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Sample records for rede neuronal artificial

  1. EXPERIMENTOS CON UNA PROTECCION BASADA EN REDES DE NEURONAS ARTIFICIALES;EXPERIMENTS WITH A PROTECTION BASED ON ARTIFICIALS NEURONS NETWORKS

    Directory of Open Access Journals (Sweden)

    Orlys Ernesto - Torres Breffe y otros

    2011-11-01

    Full Text Available En este trabajo se muestran los resultados de los experimentos físicos realizados con una protección basadatotalmente en Redes de Neuronas Artificiales para un transformador eléctrico a escala de laboratorio. Se demuestraque unas Redes de Neuronas Artificiales entrenadas, con datos provenientes de regímenes simuladosmatemáticamente, opera correctamente con señales de regímenes provenientes de casos reales, al menos a escalade laboratorio y con niveles reducidos de intensidad. Se describe la instalación experimental, tanto desde el puntode vista de hardware como software utilizando la tecnología de National Instrument. Se entrenan diferentes tipos deRedes Neuronales y todas aprendieron a proteger correctamente. Estos experimentos establecen las pautas para eldesarrollo de Relés Electrónicos Inteligentes que no se ajustarían, al menos con datos y valores de difícilcomprensión como los actuales relés, sino que se entrenarían una vez mediante la simulación matemática y laexperiencia práctica los haría cada vez mejores.In this work is shown the results of the physical experiments done with a protection totally based in Artificial NeuralNetworks for an electric transformer of the laboratory scale. Its demonstrated that some Artificial Neural Networkstrained with data coming from a mathematically simulated regimens, it operates correctly with signals coming fromreal cases, at least to laboratory scale and with reduced levels of intensity. The experimental installation is described,so much from the hardware and software point of view, using the technology of National Instrument. Different typesof Artificial Neural Nets are trained and all learned how to protect correctly. These experiments establish the rules forthe development of Intelligent Electronic Relays that would not be adjusted, at least with complex data and valueslike the current relays, they will be trained once from the mathematically simulation and the practical

  2. Recognition of faults patterns in electric generators using artificial neurons networks; Reconocimiento de patrones de fallas en generadores electricos empleando redes neuronales artificiales

    Energy Technology Data Exchange (ETDEWEB)

    Rocha Sanchez, Martha Alicia

    1999-03-01

    This work present the development of a reprocessing method to reduce the information of the original data and to maintain the essential information of the data that enter the reduction process. The obtaining of these data is performed with the aid of the ICM ++ (ICMsystems), from which vectors or n-uplos of elements are obtained. This investigation allowed to analyze an evaluation of the paradigms of artificial neural networks, with the intention of detecting which of these paradigms would evolve better with the problem of fault diagnosis in electric generators. From this a prototype system was developed called diagnosis of faults in electrical generators, which automatically will recognize faults in electrical generators by means of the interpretation of the recording of partial discharges. [Spanish] El presente trabajo presenta el desarrollo de un metodo de reprocesamiento para reducir informacion de los datos originales y mantener la informacion esencial de los datos que entran al proceso de reduccion. La obtencion de estos datos se realiza con la ayuda del ICM ++ (ICMsystems), de los cuales se obtienen vectores o n-uplos de elementos. Esta investigacion permitio analizar una evaluacion de los paradigmas de redes neuronales artificiales, con el objeto de detectar cual de estos paradigmas se desempenaria mejor con el problema de diagnostico de fallas en generadores electricos. A partir de esto se desarrollo un sistema prototipo llamado diagnostico de fallas en generadores electricos, el cual automaticamente reconocera fallas en los generadores electricos mediante la interpretacion de registro de descargas parciales.

  3. A program for assisting automatic generation control of the ELETRONORTE using artificial neural network; Um programa para assistencia ao controle automatico de geracao da Eletronorte usando rede neuronal artificial

    Energy Technology Data Exchange (ETDEWEB)

    Brito Filho, Pedro Rodrigues de; Nascimento Garcez, Jurandyr do [Para Univ., Belem, PA (Brazil). Centro Tecnologico; Charone, Junior, Wady [Centrais Eletricas do Nordeste do Brasil S.A. (ELETRONORTE), Belem, PA (Brazil)

    1994-12-31

    This work presents an application of artificial neural network as a support to decision making in the automatic generation control (AGC) of the ELETRONORTE. It uses a software to auxiliary in the decisions in real time of the AGC. (author) 2 refs., 6 figs., 1 tab.

  4. Neuronal nets in robotics; Redes neuronales en robotica

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez Sanchez, Raul

    1999-06-01

    The paper gives a generic idea of the solutions that the neuronal nets contribute to the robotics. The advantages and the inconveniences are exposed that have regarding the conventional techniques. It also describe the more excellent applications as the pursuit of trajectories, the positioning based on images, the force control or of the mobile robots management, among others.

  5. Estimação do volume de árvores utilizando redes neurais artificiais Estimate of tree volume using artificial neural nets

    Directory of Open Access Journals (Sweden)

    Eric Bastos Gorgens

    2009-12-01

    Full Text Available Rede neural artificial consiste em um conjunto de unidades que contêm funções matemáticas, unidas por pesos. As redes são capazes de aprender, mediante modificação dos pesos sinápticos, e generalizar o aprendizado para outros arquivos desconhecidos. O projeto de redes neurais é composto por três etapas: pré-processamento, processamento e, por fim, pós-processamento dos dados. Um dos problemas clássicos que podem ser abordados por redes é a aproximação de funções. Nesse grupo, pode-se incluir a estimação do volume de árvores. Foram utilizados quatro arquiteturas diferentes, cinco pré-processamentos e duas funções de ativação. As redes que se apresentaram estatisticamente iguais aos dados observados também foram analisadas quanto ao resíduo e à distribuição dos volumes e comparadas com a estimação de volume pelo modelo de Schumacher e Hall. As redes neurais formadas por neurônios, cuja função de ativação era exponencial, apresentaram estimativas estatisticamente iguais aos dados observados. As redes treinadas com os dados normalizados pelo método da interpolação linear e equalizados tiveram melhor desempenho na estimação.The artificial neural network consists of a set of units containing mathematical functions connected by weights. Such nets are capable of learning by means of synaptic weight modification, generalizing learning for other unknown archives. The neural network project comprises three stages: pre-processing, processing and post-processing of data. One of the classical problems approached by networks is function approximation. Tree volume estimate can be included in this group. Four different architectures, five pre-processings and two activation functions were used. The nets which were statistically similar to the observed data were also analyzed in relation to residue and volume and compared to the volume estimate provided by the Schumacher and Hall equation. The neural nets formed by

  6. A Neuron- and a Synapse Chip for Artificial Neural Networks

    DEFF Research Database (Denmark)

    Lansner, John; Lehmann, Torsten

    1992-01-01

    A cascadable, analog, CMOS chip set has been developed for hardware implementations of artificial neural networks (ANN's):I) a neuron chip containing an array of neurons with hyperbolic tangent activation functions and adjustable gains, and II) a synapse chip (or a matrix-vector multiplier) where...

  7. Neuronal networks for the study of buildings thermal behavior; Redes neuronales para el estudio del comportamiento termico de edificios

    Energy Technology Data Exchange (ETDEWEB)

    Marincic, Irene [Universidad de Sonora (Mexico); Del Rio, J. Antonio [Centro Morelense de Innovacion y Transferencia Tecnologica (Mexico)

    2009-07-15

    The evaluation as well as the prediction of buildings thermal behavior involves complex calculations mainly because of its enormous number of variables, many of them difficult to determine. For this type of problems, a possibility is to resort to models of the black box type, that allow the characterization of the building with very few variables, for then to be able to predict its behavior under other circumstances, with greater certainty. One of the black box models of more and more used in diverse disciplines, is the one of the artificial neuronal networks (ANN). These can be used as an alternative method of analysis and prediction, particularly for cases in which many variables take part. In this work a preliminary study is presented that analyzes the accuracy of a model of neuronal network for the prediction of the inside temperatures of a building, given the outside temperatures. A very simple network, of 3 neurons, located in 2 layers is considered. The results of the inside temperatures obtained in the learning as well as in the prediction stage are analyzed, comparing them with the ones obtained using another model of black box previously developed by the authors, the one of the function responded in the dominion of frequencies. [Spanish] Tanto la evaluacion como la prediccion del comportamiento termico de los edificios involucra calculos complejos sobre todo por su enorme numero de variables, muchas de ellas dificiles de determinar. Para este tipo de problemas, una posibilidad es recurrir a modelos del tipo caja negra, que permiten caracterizar al edificio como muy pocas variables, para luego poder predecir su comportamiento bajo otras circunstancias, como mayor certeza. Uno de los modelos de caja negra cada vez mas utilizado en diversas disciplinas, es el de las redes neuronales artificiales (ANN). Estas pueden ser usadas como metodo alternativo de analisis y sobre todo de prediccion, particularmente para los casos en que intervienen muchas variables. En

  8. Artificial spatiotemporal touch inputs reveal complementary decoding in neocortical neurons.

    Science.gov (United States)

    Oddo, Calogero M; Mazzoni, Alberto; Spanne, Anton; Enander, Jonas M D; Mogensen, Hannes; Bengtsson, Fredrik; Camboni, Domenico; Micera, Silvestro; Jörntell, Henrik

    2017-04-04

    Investigations of the mechanisms of touch perception and decoding has been hampered by difficulties in achieving invariant patterns of skin sensor activation. To obtain reproducible spatiotemporal patterns of activation of sensory afferents, we used an artificial fingertip equipped with an array of neuromorphic sensors. The artificial fingertip was used to transduce real-world haptic stimuli into spatiotemporal patterns of spikes. These spike patterns were delivered to the skin afferents of the second digit of rats via an array of stimulation electrodes. Combined with low-noise intra- and extracellular recordings from neocortical neurons in vivo, this approach provided a previously inaccessible high resolution analysis of the representation of tactile information in the neocortical neuronal circuitry. The results indicate high information content in individual neurons and reveal multiple novel neuronal tactile coding features such as heterogeneous and complementary spatiotemporal input selectivity also between neighboring neurons. Such neuronal heterogeneity and complementariness can potentially support a very high decoding capacity in a limited population of neurons. Our results also indicate a potential neuroprosthetic approach to communicate with the brain at a very high resolution and provide a potential novel solution for evaluating the degree or state of neurological disease in animal models.

  9. Modelagem do sistema de resfriamento por imersão de carcaças de frangos utilizando redes neurais artificiais = Modeling of the poultry carcass immersion chilling system using artificial neural networks

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    Túlio Klassen

    2009-04-01

    Full Text Available A modelagem matemática fenomenológica do processo de resfriamento decarcaças de frango em chillers é complexa pela quantidade de variáveis que interferem no processo, além de tratar de um problema que envolve transferência de calor e de massa em regime transeniente. Uma alternativa para modelar este tipo de sistema é o emprego deRedes Neurais Artificiais. Neste trabalho foram investigadas diversas estruturas de redes com uma camada intermediária para modelar o processo de resfriamento de frangos. Foram testadas diferentes arquiteturas alterando os números de neurônios das camadas de entrada e intermediária. Foram utilizados dados coletados na empresa Sadia–Toledo, Estado do Paraná, para treinamento e validação das redes. As variáveis de entrada da rede eram: massa da carcaça, temperatura antes do resfriamento, temperatura da camisa de propilenoglicol,vazão de água em cada módulo, tempo de residência e temperatura da água de renovação; a temperatura do frango na saída do último tanque de resfriamento era a variável de saída. Os resultados obtidos mostraram que as redes representam apropriadamente o processo e que arede com estrutura 8-24-1 foi a que melhor modelou o sistema investigado.The process of cooling chicken carcasses by immersing themin mixture of cold water and ice (chillers is complex. It is very difficult to represent it by a transport phenomenon model. In this work, artificial neural networks were used with an intermediary layer in the description and modeling of the cooling process of chickens.Different architectures of the neural network were tested, altering the numbers of input and hidden units. Data supplied by the Sadia-Toledo Company were used for training and validation of the neural networks. The input variables selected for the model were thefollowing: carcass weight, initial temperature, propylene glycol temperature with external circulation, water flow rate of water in each tank, renewal

  10. able utilizando redes neuronales artificiales; UTILIZATION OF ARTIFICIAL NEURAL NETWORK IN THE SIMULATION AND CONTROL OF WIND TURBINE GENERATORS WITH VARIABLE SPEED AND VARIABLE PITCH.

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    Osley López González

    2011-02-01

    Full Text Available Con el objetivo de aprovechar al máximo la energía del viento y, a la vez, llevar a cabo un control rápido ypreciso de la potencia máxima suministrada al aumentar la misma se han venido utilizando cada vez mássistemas de control capaces de operar en el punto óptimo de entrega de potencia para determinadosvalores de velocidad del viento y limitarla cuando éste supera su valor máximo. Este sistema de control,considerado en su conjunto, debe responder con la exactitud, estabilidad y rapidez necesaria ante lavariabilidad y aleatoriedad del viento. La relación entre sus variables de salida (velocidad de la turbina ypaso de la pala y la de entrada (velocidad del viento que sea capaz de aprovechar la máxima potenciadisponible en el viento en una zona de trabajo y de limitarla en otra, es altamente complicada puesdepende de factores constructivos y de diseño de la turbina y del generador. Esta característica es muydifícil de representar (sea con el objetivo de simulación o con el de control mediante relacionesfuncionales matemáticas convencionales.En este trabajo los autores proponen representar dicha relaciónmediante la utilización de Redes Neuronales Artificiales entrenadas para ser capaces de responderadecuadamente ante cualquier entrada. Basados en los parámetros y características de un aerogeneradorreal de velocidad y paso variables y utilizando el toolbox de Redes Neuronales del MATLAB SIMULINK losautores obtuvieron un modelo neuronal del sistema de control de la velocidad y el paso de la turbinacomprobando su correcta operación ante diferentes perturbaciones de la red eléctrica mediante estemismo lenguaje de simulación. Se demostró que estas redes pueden ser utilizadas con éxito en lasimulación y el control de este tipo de máquinas en cualquier condición de operación. In order to capture the maximum energy from the wind, control systems operating always at an optimumpower has been utilized. This control system

  11. A utilização de uma rede neural artificial para previsão da incidência da malária no município de Cantá, estado de Roraima Use of an artificial neural network to predict the incidence of malaria in the city of Cantá, state of Roraima

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    Guilherme Bernardino da Cunha

    2010-10-01

    Full Text Available INTRODUÇÃO: A malária é uma doença endêmica na Amazônia Legal Brasileira, apresentando riscos diferentes para cada região. O Município de Cantá, no Estado de Roraima, apresentou para todo o período estudado, um dos maiores índices parasitários anuais do Brasil, com valor sempre maior que 50. O presente estudo visa à utilização de uma rede neural artificial para previsão da incidência da malária nesse município, a fim de auxiliar os coordenadores de saúde no planejamento e gestão dos recursos. MÉTODOS: Os dados foram coletados no site do Ministério da Saúde, SIVEP - Malária entre 2003 e 2009. Estruturou-se uma rede neural artificial com três neurônios na camada de entrada, duas camadas intermediárias e uma camada de saída com um neurônio. A função de ativação foi à sigmoide. No treinamento, utilizou-se o método backpropagation, com taxa de aprendizado de 0,05 e momentum 0,01. O critério de parada foi atingir 20.000 ciclos ou uma meta de 0,001. Os dados de 2003 a 2008 foram utilizados para treinamento e validação. Comparam-se os resultados com os de um modelo de regressão logística. RESULTADOS: Os resultados para todos os períodos previstos mostraram-se que as redes neurais artificiais obtiveram um menor erro quadrático médio e erro absoluto quando comparado com o modelo de regressão para o ano de 2009. CONCLUSÕES: A rede neural artificial se mostrou adequada para um sistema de previsão de malária no município estudado, determinando com pequenos erros absolutos os valores preditivos, quando comparados ao modelo de regressão logística e aos valores reais.INTRODUCTION: Malaria is endemic in the Brazilian Amazon region, with different risks for each region. The City of Cantá, State of Roraima, presented one of the largest annual parasite indices in Brazil for the entire study period, with a value always greater than 50. The present study aimed to use an artificial neural network to predict the

  12. Estimação da evapotranspiração de referência no estado do Rio de Janeiro usando redes neurais artificiais Reference evapotranspiration estimate in Rio de Janeiro state using artificial neural networks

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    Sidney S. Zanetti

    2008-04-01

    Full Text Available Propor uma rede neural artificial (RNA para estimar a evapotranspiração de referência (ETo em função das coordenadas de posição geográfica e da temperatura do ar no Estado do Rio de Janeiro, motivou a realização do presente estudo. Os dados utilizados no treinamento da rede foram obtidos de 17 séries históricas de elementos climáticos localizadas nesse Estado. A ETo diária calculada pelo método de Penman-Monteith (FAO-56 foi utilizada como referência para treinar as redes. As RNAs, do tipo perceptron de múltiplas camadas, foram treinadas para estimar a ETo em função da latitude, longitude, altitude, temperatura média do ar, amplitude térmica diária e dia do ano. Após o treinamento com várias configurações de rede, selecionou-se a que apresentou o melhor desempenho, a qual é composta de apenas uma camada intermediária (com vinte neurônios e função de ativação do tipo sigmóide logística e uma camada de saída (com um neurônio e função de ativação linear. Pelos resultados obtidos conclui-se que, levando-se em consideração apenas as coordenadas de posição geográfica e a temperatura do ar, pode-se estimar a ETo (valores diários em 17 localidades do Estado do Rio de Janeiro usando uma RNA.This work was performed with the aim of proposing an artificial neural network (ANN to estimate the reference evapotranspiration (ETo as a function of geographic position coordinates and air temperature in the State of Rio de Janeiro. Data used for the network training were collected from 17 historical time series of climatic elements located in the State of Rio de Janeiro. The daily ETo calculated by Penman-Monteith (FAO-56 method was used as a reference for network training. ANNs of multilayer perceptron type were trained to estimate ETo as a function of latitude, longitude, altitude, mean air temperature, thermal daily amplitude and day of the year. After training with different network configurations, the one showing

  13. Artificial Neural Networks for Predicting Real Estate Prices || Redes neuronales artificiales para la predicción de precios inmobiliarios

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    Núñez Tabales, Julia M.

    2013-01-01

    Full Text Available Econometric models, in the estimation of real estate prices, are a useful and realistic approach for buyers and for local and fiscal authorities. From the classical hedonic models to more data driven procedures, based on Artificial Neural Networks (ANN, many papers have appeared in economic literature trying to compare the results attained with both approaches. We insist on the use of ANN, when there is enough statistical information, and will detail some comparisons to hedonic modeling, in a medium size city in the South of Spain, with an extensive set of data spanning over several years, collected before the actual downturn of the market. Exogenous variables include each dwelling's external and internal data (both numerical and qualitative, and data from the building in which it is located and its surroundings. Alternative models are estimated for several time intervals, and enabling the comparison of the effects of the rising prices during the bull market over the last decade. || Los modelos econométricos en la valoración de precios inmobiliarios constituyen una herramienta útil tanto para los compradores como para las autoridades locales y fiscales. Desde los modelos hedónicos clásicos hasta los planteamientos actuales a través de redes neuronales artificiales (RNA, han tenido lugar numerosas aportaciones en la literatura económica que tratan de comparar los resultados de ambos métodos. Insistimos en el empleo de RNA en el caso de disponer de suficiente información estadística. En este trabajo se aplica dicha metodología en una ciudad de tamaño medio situada en el sur de España, utilizando una extensa muestra de datos que comprende varios años precedentes a la crisis actual. Las variables utilizadas -tanto cuantitativas como cualitativas- incluyen datos externos e internos de la vivienda, del edificio en el que está localizada, así como de su entorno. Se construyen varios modelos alternativos para distintos intervalos de

  14. Performance of networks of artificial neurons: The role of clustering

    International Nuclear Information System (INIS)

    Kim, Beom Jun

    2004-01-01

    The performance of the Hopfield neural network model is numerically studied on various complex networks, such as the Watts-Strogatz network, the Barabasi-Albert network, and the neuronal network of Caenorhabditis elegans. Through the use of a systematic way of controlling the clustering coefficient, with the degree of each neuron kept unchanged, we find that the networks with the lower clustering exhibit much better performance. The results are discussed in the practical viewpoint of application, and the biological implications are also suggested

  15. Uso da rede neural artificial no planejamento cirúrgico da correção do estrabismo Neural network approach for planning surgical correction of strabismus

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    Murilo Barreto Souza

    2004-06-01

    Full Text Available OBJETIVO: Desenvolver uma rede neural artificial para planejar a estratégia cirúrgica em pacientes portadores de estrabismo sensorial, com desvio horizontal. MÉTODOS: Foi realizado estudo retrospectivo envolvendo 95 pacientes portadores de estrabismo sensorial, atendidos no Ambulatório de Motilidade Ocular Extrínseca do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. Foi construída uma rede neural artificial utilizando-se o Java Neural Network 1.1. Foram utilizados 68 pacientes para treinamento e validação da rede e 27 para testar o seu funcionamento. RESULTADOS: Dos 68 pacientes utilizados no treinamento da rede, 37 apresentavam exotropia e 31 esotropia. O método utilizado para treinamento da rede foi o "backpropagation". A taxa de aprendizado utilizada foi de 0,6, e a taxa de tolerância de erro 0,05. Dos 27 pacientes utilizados para avaliação da eficácia da rede, 18 apresentavam exotropia, e 9 esotropia. A eficácia da rede foi avaliada pela média da diferença entre os resultados fornecidos pela rede, e as indicações originais. Nos pacientes com exotropia o erro médio foi de 0,4 mm (±0,4, para o retrocesso do músculo reto lateral, e de 0,3 mm (±0,3, para a ressecção do músculo reto medial. Nas esotropias, o erro médio foi de 0,2 mm (±0,2, para o retrocesso do músculo reto medial e de 0,5 mm (±0,3, para ressecção do músculo reto lateral. CONCLUSÃO: A rede neural artificial, por sua característica de simular o sistema nervoso central biológico, e sua capacidade de realizar tarefas cognitivas, é opção viável para auxiliar no planejamento cirúrgico da cor-reção do estrabismo.PURPOSE: To develop a neural network model for planning of the surgical strategy of patients with sensorial strabismus. METHODS: In this retrospective study, medical records of 95 patients with sensorial strabismus were reviewed. All patients were seen at the Strabismus Sector of the Hospital das Cl

  16. Rapid Integration of Artificial Sensory Feedback during Operant Conditioning of Motor Cortex Neurons.

    Science.gov (United States)

    Prsa, Mario; Galiñanes, Gregorio L; Huber, Daniel

    2017-02-22

    Neuronal motor commands, whether generating real or neuroprosthetic movements, are shaped by ongoing sensory feedback from the displacement being produced. Here we asked if cortical stimulation could provide artificial feedback during operant conditioning of cortical neurons. Simultaneous two-photon imaging and real-time optogenetic stimulation were used to train mice to activate a single neuron in motor cortex (M1), while continuous feedback of its activity level was provided by proportionally stimulating somatosensory cortex. This artificial signal was necessary to rapidly learn to increase the conditioned activity, detect correct performance, and maintain the learned behavior. Population imaging in M1 revealed that learning-related activity changes are observed in the conditioned cell only, which highlights the functional potential of individual neurons in the neocortex. Our findings demonstrate the capacity of animals to use an artificially induced cortical channel in a behaviorally relevant way and reveal the remarkable speed and specificity at which this can occur. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  17. Redes neurais artificiais na classificação de frutos: cenário bidimensional Fruit sorting using artificial neural networks: bidimensional case

    Directory of Open Access Journals (Sweden)

    Jean Paulo Silva Ramos

    2003-04-01

    Full Text Available Inúmeras são as atividades agrícolas que necessitam de interação humana nos processos decisórios, e entre elas encontra-se a classificação de frutos. O consumo de frutos "in natura" exige altíssimo nível de qualidade, demandando um processo classificatório mais acurado. A classificação de frutos depende do reconhecimento de padrões natural ou artificial, de acordo com algumas categorias pré-definidas. Uma vez que um padrão de um fruto está sendo classificado, esse deve ser comparado com algum outro padrão armazenado. A maior parte da classificação de frutos é baseada na classificação humana.Este trabalho apresenta a possibilidade de uso de redes neurais artificiais no desenvolvimento de modelos de classificação de frutos por meio de vetores de padrões. Este trabalho foi desenvolvido no Departamento de Máquinas Agrícolas da Faculdade de Engenharia Agrícola da Universidade Estadual de Campinas, as redes neurais armazenaram os vetores de padrões de frutos peso, diâmetro. Esses componentes vetoriais associados entre si interagiram, determinando um vetor padrão de saída de acordo com os padrões de frutos armazenados. Para atingir esses objetivos, foi usada uma rede Perceptron de múltiplas camadas, com algoritmo de treinamento tipo retro-propagação para armazenar os vetores de padrões de frutos e para classificação desses padrões de entrada. A rede treinada conseguiu aprender a relação entre vetores de entrada e saída, demonstrando a potencialidade do uso de tais ferramentas na classificação artificial.Agriculture is one of the economic activities that more require the presence human being in the decision taking. Innumerable are the processes that require some type of human being interference in the conclusion of the processes. Fruit Sorting depends on human or artificial pattern recognition according to some pre defined categories. Once a fruit pattern is under classification, this one must be compared to

  18. Orientation of a 3D object: implementation with an artificial neural network using a programmable logic device;Orientacion de un objeto 3D : implementacion de redes neuronales artificiales utilizando logica programable

    Energy Technology Data Exchange (ETDEWEB)

    Carnevale, Federico J [Universidad Nacional de Cuyo, Instituto Balseiro, Centro Atomico Bariloche (Argentina)

    2010-07-01

    Complex information extraction from images is a key skill of intelligent machines, with wide application in automated systems, robotic manipulation and human-computer interaction. However, solving this problem with traditional, geometric or analytical, strategies is extremely difficult. Therefore, an approach based on learning from examples seems to be more appropriate. This thesis addresses the problem of 3D orientation, aiming to estimate the angular coordinates of a known object from an image shot from any direction. We describe a system based on artificial neural networks to solve this problem in real time. The implementation is performed using a programmable logic device. The digital system described in this paper has the ability to estimate two rotational coordinates of a 3D known object, in ranges from -80{sup 0} to 80{sup 0}. The operation speed allows a real time performance at video rate. The system accuracy can be successively increased by increasing the size of the artificial neural network and using a larger number of training examples;La extraccion de informacion compleja a partir de imagenes es una habilidad clave en las maquinas inteligentes con vasta aplicacion en los sistemas automatizados, la manipulacion robotica y la interaccion humano-computadora. Sin embargo, resulta una tarea extremadamente dificil de resolver con estrategias clasicas, geometricas o analiticas. Por lo tanto, un enfoque basado en aprendizaje a partir de ejemplos parece mas adecuado. Esta tesis trata acerca del problema de orientacion 3D, cuyo objetivo consiste en estimar las coordenadas angulares de un objeto conocido, a partir de una imagen tomada desde cualquier direccion. Se describe un sistema, basado en redes neuronales artificiales, para resolver este problema en tiempo real. La implementacion, capaz de funcionar a frecuencia de video, se realiza utilizando un dispositivo de logica programable. El sistema digital final demuestra la capacidad de estimar dos coordenadas

  19. O Uso de Famílias de Circuitos e Rede Neural Artificial para Previsão de Demanda de Energia Elétrica

    Directory of Open Access Journals (Sweden)

    José Leomar Todesco

    2004-08-01

    denominado método indireto de previsão da carga, e dele decorrem todos os cálculos elétricos do circuito para aferir seu desempenho quanto à qualidade dos níveis de tensão, do carregamento dos equipamentos e condutores, do balanceamento da carga, bem como das perdas elétricas. Este artigo apresenta uma proposta de estudo das famílias de circuitos (residencial, comercial, industrial, rural, público e outros utilizando informações sobre o consumo de energia através da aplicação de algoritmos de clustering e, posteriormente, da aplicação de uma Rede Neural Artificial (RNA para a aproximação das curvas de demanda para as famílias identificadas. A RNA utilizada foi a Radial Basis Function (RBF, por ser um aproximador universal. São também apresentados no artigo testes comparativos realizados com o modelo de regressão linear simples e a RBF.

  20. Artificial neuron-glia networks learning approach based on cooperative coevolution.

    Science.gov (United States)

    Mesejo, Pablo; Ibáñez, Oscar; Fernández-Blanco, Enrique; Cedrón, Francisco; Pazos, Alejandro; Porto-Pazos, Ana B

    2015-06-01

    Artificial Neuron-Glia Networks (ANGNs) are a novel bio-inspired machine learning approach. They extend classical Artificial Neural Networks (ANNs) by incorporating recent findings and suppositions about the way information is processed by neural and astrocytic networks in the most evolved living organisms. Although ANGNs are not a consolidated method, their performance against the traditional approach, i.e. without artificial astrocytes, was already demonstrated on classification problems. However, the corresponding learning algorithms developed so far strongly depends on a set of glial parameters which are manually tuned for each specific problem. As a consequence, previous experimental tests have to be done in order to determine an adequate set of values, making such manual parameter configuration time-consuming, error-prone, biased and problem dependent. Thus, in this paper, we propose a novel learning approach for ANGNs that fully automates the learning process, and gives the possibility of testing any kind of reasonable parameter configuration for each specific problem. This new learning algorithm, based on coevolutionary genetic algorithms, is able to properly learn all the ANGNs parameters. Its performance is tested on five classification problems achieving significantly better results than ANGN and competitive results with ANN approaches.

  1. Rede residencial

    DEFF Research Database (Denmark)

    Charbonnier, Benoit; Wessing, Henrik; Lanoo, Bart

    2012-01-01

    Com a proliferação dos serviços a distância sobre as redes das operadoras e conectividade de alta velocidade entre dispositivos como TVs, centros de mídia ou PCs, é cada vez maior a pressão sobre as redes residenciais, que no futuro deverão suportar elevadas taxas de dados (acima de 1 Gbit/s), Qo...

  2. Redes empresariales

    OpenAIRE

    Sibylla Brodzinski

    2015-01-01

    Sofisticadas redes semiprivadas de telecomunicaciones que hasta hace pocos años eran ideas irrealizables, hoy cruzan las fronteras y enlazan los países intercambiando datos y agilitando la toma de decisiones. Hoy, la mayoría de las grandes y algunas pequeñas empresas que operan en la región han descubierto las ventajas de estar conectadas al mundo directamente a través de redes digitales.

  3. Artificial Induction of Associative Olfactory Memory by Optogenetic and Thermogenetic Activation of Olfactory Sensory Neurons and Octopaminergic Neurons in Drosophila Larvae.

    Science.gov (United States)

    Honda, Takato; Lee, Chi-Yu; Honjo, Ken; Furukubo-Tokunaga, Katsuo

    2016-01-01

    The larval brain of Drosophila melanogaster provides an excellent system for the study of the neurocircuitry mechanism of memory. Recent development of neurogenetic techniques in fruit flies enables manipulations of neuronal activities in freely behaving animals. This protocol describes detailed steps for artificial induction of olfactory associative memory in Drosophila larvae. In this protocol, the natural reward signal is substituted by thermogenetic activation of octopaminergic neurons in the brain. In parallel, the odor signal is substituted by optogenetic activation of a specific class of olfactory receptor neurons. Association of reward and odor stimuli is achieved with the concomitant application of blue light and heat that leads to activation of both sets of neurons in living transgenic larvae. Given its operational simplicity and robustness, this method could be utilized to further our knowledge on the neurocircuitry mechanism of memory in the fly brain.

  4. Desenvolvimento e análise de uma rede neural artificial para estimativa da erosividade da chuva para o Estado de São Paulo Estimates of rainfall erosivity in São Paulo state by an artificial neural network

    Directory of Open Access Journals (Sweden)

    Michel Castro Moreira

    2006-12-01

    Full Text Available O conhecimento do valor da erosividade da chuva (R de determinada localidade é fundamental para a estimativa das perdas de solo feitas a partir da Equação Universal de Perdas de Solo, sendo, portanto, de grande importância no planejamento conservacionista. A fim de obter estimativas do valor de R para localidades onde este é desconhecido, desenvolveu-se uma rede neural artificial (RNA e analisou-se a acurácia desta com o método de interpolação "Inverso de uma Potência da Distância" (ID. Comparando a RNA desenvolvida com o método de interpolação ID, verificou-se que a primeira apresentou menor erro relativo médio na estimativa de R e melhor índice de confiança, classificado como "Ótimo", podendo, portanto, ser utilizada no planejamento de uso, manejo e conservação do solo no Estado de São Paulo.Knowledge on rainfall erosivity (R of particular sites is fundamental for soil loss estimation by the Universal Soil Loss Equation (USLE and therefore highly important in conservation planning. In order to obtain the R value estimates for places where it is unknown, an artificial neural network (ANN was developed for the state of São Paulo, and its accuracy compared with the Inverse Distance Weighted (IDW interpolation method. The developed ANN presented a smaller mean relative error in the R estimation and a confidence index classified as "excellent", better than the IDW. ANN can therefore be used to estimate R values for soil use planning, management and conservation in São Paulo state.

  5. COMPUTER DYNAMICS SIMULATION OF DRUG DEPENDENCE THROUGH ARTIFICIAL NEURONAL NETWORK: PEDAGOGICAL AND CLINICAL IMPLICATIONS

    Directory of Open Access Journals (Sweden)

    G. SANTOS

    2008-05-01

    Full Text Available To develop and to evaluate the efficiency of a software able to simulate a virtual patient at different stages of addition was the main goal and challenge of this work. We developed the software in Borland™ Delphi  5®  programming language. Techniques of artificial intelligence, neuronal networks and expert systems, were responsible for modeling the neurobiological structures and mechanisms of the interaction with the drugs used. Dynamical simulation and  hypermedia were designed to increase the software’s interactivity which was able to show graphical information from virtual instrumentation and from realistic functional magnetic resonance imaging display. Early, the program was designed to be used by undergraduate students to improve their neurophysiologic learn, based not only in an interaction of membrane receptors with drugs, but in such a large behavioral simulation. The experimental manipulation of the software was accomplished by: i creating a virtual patient from a normal mood to a behavioral addiction, increasing gradatively: alcohol, opiate or cocaine doses. ii designing an approach to treat the patient, to get total or partial remission of behavioral disorder by combining psychopharmacology and psychotherapy. Integration of dynamic simulation with hypermedia and artificial intelligence has been able to point out behavioral details as tolerance, sensitization and level of addiction to drugs of abuse and so on, turned into a potentially useful tool in the development of teaching activities on several ways, such as education as well clinical skills, in which it could assist patients, families and health care to improve and test their knowledge and skills about different faces supported by drugs dependency. Those features are currently under investigation.

  6. Redes convergentes

    Directory of Open Access Journals (Sweden)

    Ángela Marcela Mejía Fajardo

    2004-01-01

    Full Text Available Las redes convergentes o redes de multiservicio hacen referencia a la integración de los servicios de voz, datos y video sobre una sola red basada en IP como protocolo de nivel de red. En este artículo se presenta la integración de servicios de voz sobre redes IP (VoIP como ejemplo de red convergente. La arquitectura de esta red está constituida básicamente, por el media gateway, el controlador de media gateway, el gateway de señalización y el gatekeeper. Las redes de convergencia han tenido y tendrán aún dificultades técnicas qué superar ya que los distintos servicios por ofrecer tienen diferentes características y requerimientos de red, por tanto es importante hablar aquí de ingeniería de tráfico y mecanismos que garanticen calidades de servicio.

  7. Previsão de estabilidade de óleos vegetais através da rede de inteligência artificial

    Directory of Open Access Journals (Sweden)

    VALE Cauê M.

    2000-01-01

    Full Text Available Redes Neurais Artificiais são técnicas computacionais que se utilizam de um modelo matemático capaz de adquirir conhecimentos pela experiência; esse comportamento inteligente da rede provém das interações entre unidades de processamento, denominadas de neurônios artificiais. O objetivo deste trabalho foi criar uma rede neural capaz de prever a estabilidade de óleos vegetais, a partir de dados de suas composições químicas, visando um modelo para a previsão da shelf-life de óleos vegetais, tendo como parâmetros apenas dados de suas composições químicas. Os primeiros passos do processo de desenvolvimento da rede consistiram na coleta de dados relativos ao problema e sua separação em um conjunto de treinamento e outro de testes. Estes conjuntos apresentaram como variáveis dados de composição química, que incluíram os valores totais em ácidos graxos, fenóis, tocoferóis e a composição individual em ácidos graxos. O passo seguinte foi a execução do treinamento, onde o padrão de entrada apresentado à rede como parâmetro de estabilidade foi o índice de peróxido, determinado experimentalmente por um período de 16 dias de armazenagem na ausência de luz, a 65ºC. Após o treinamento foi testada a capacidade de previsão adquirida pela rede, em função do parâmetro de estabilidade adotado, mas com um novo grupo de óleos. Seguindo o teste, foi determinada a correlação linear entre os valores de estabilidade previstos pela rede e aqueles determinados experimentalmente. Com os resultados obtidos, pode-se confirmar a viabilidade de previsão da estabilidade de óleos vegetais pela rede neural, a partir de dados de sua composição química, utilizando como parâmetro de estabilidade o índice de peróxido.

  8. ESTUDIO DE SERIES TEMPORALES DE CONTAMINACIÓN AMBIENTAL MEDIANTE TÉCNICAS DE REDES NEURONALES ARTIFICIALES TIME SERIES ANALYSIS OF ATMOSPHERE POLLUTION DATA USING ARTIFICIAL NEURAL NETWORKS TECHNIQUES

    Directory of Open Access Journals (Sweden)

    Giovanni Salini Calderón

    2006-12-01

    Full Text Available Se diseñó una red neuronal artificial (RNA para hacer predicciones de valores de concentraciones horarias de material particulado fino en la atmósfera. El estudio está basado en los datos de tres años de series de tiempo de pm2.5 (material particulado suspendido de 2,5 micrones de diámetro, obtenidos en una estación céntrica de la Red MACAM de la ciudad de Santiago de Chile, entre los años 1994 y 1996. Para obtener el espaciamiento óptimo de los datos, así como el número de datos hacia atrás necesarios para pronosticar el valor futuro, se aplicaron dos test estándar usados en estudio de sistemas dinámicos, como Información Mutua promedio (AMI y Falsos Vecinos más Cercanos (FNN. De esta manera se encontró que lo más conveniente era considerar como entrada los datos de PM2.5 cada seis horas durante un día (cuatro datos, y en base a ellos predecir el dato siguiente. Una vez fijo el número de variables de entrada y elegida la variable a pronosticar, se diseñó un modelo predictivo basado en la técnica de RNA. El tipo de modelo de RNA usado fue uno de multicapas, alimentado hacia adelante y entrenado mediante la técnica de propagación hacia atrás. Se probaron redes sin capa oculta y con una y dos capas ocultas. El mejor modelo resultó ser con una capa oculta, a diferencia de lo obtenido en trabajo anterior que reportaba que la red sin capa oculta era más eficiente. Los resultados fueron más precisos que los obtenidos con un modelo de persistencia (el valor en seis horas más será el mismo que el actual.An artificial neural network for the forecasting of concentrations of fine particulate matter in the atmosphere was designed. The data set analyzed corresponds to three years of pm2.5 time series (particulate matter in suspension with aerodynamic diameter less than 2,5 microns, measured in a station that belongs to Santiago's monitoring network (Red MACAM and is located near downtown. We consider measurements of

  9. A Hybrid Fuzzy Time Series Approach Based on Fuzzy Clustering and Artificial Neural Network with Single Multiplicative Neuron Model

    Directory of Open Access Journals (Sweden)

    Ozge Cagcag Yolcu

    2013-01-01

    Full Text Available Particularly in recent years, artificial intelligence optimization techniques have been used to make fuzzy time series approaches more systematic and improve forecasting performance. Besides, some fuzzy clustering methods and artificial neural networks with different structures are used in the fuzzification of observations and determination of fuzzy relationships, respectively. In approaches considering the membership values, the membership values are determined subjectively or fuzzy outputs of the system are obtained by considering that there is a relation between membership values in identification of relation. This necessitates defuzzification step and increases the model error. In this study, membership values were obtained more systematically by using Gustafson-Kessel fuzzy clustering technique. The use of artificial neural network with single multiplicative neuron model in identification of fuzzy relation eliminated the architecture selection problem as well as the necessity for defuzzification step by constituting target values from real observations of time series. The training of artificial neural network with single multiplicative neuron model which is used for identification of fuzzy relation step is carried out with particle swarm optimization. The proposed method is implemented using various time series and the results are compared with those of previous studies to demonstrate the performance of the proposed method.

  10. ESTIMACIÓN DE LA CARGA DE TRANSFORMADORES DE POTENCIA UTILIZANDO UNA RED NEURONAL ARTIFICIAL

    OpenAIRE

    Agudelo, Laura; Velilla, Esteban; López, Jesús M

    2014-01-01

    En este artículo se presenta una metodología para estimar la curva de carga de transformadores de potencia utilizando redes neuronales artificiales. Para implementar la metodología propuesta se utilizaron datos reales de dos transformadores ubicados en diferentes zonas geográficas y con diferentes condiciones de operación. La técnica de estimación de carga fue implementada con datos históricos de la empresa Interconexión Eléctrica S.A (ISA). Para realizar la predicción de las curvas de carga ...

  11. Artificial neuron operations and spike-timing-dependent plasticity using memristive devices for brain-inspired computing

    Science.gov (United States)

    Marukame, Takao; Nishi, Yoshifumi; Yasuda, Shin-ichi; Tanamoto, Tetsufumi

    2018-04-01

    The use of memristive devices for creating artificial neurons is promising for brain-inspired computing from the viewpoints of computation architecture and learning protocol. We present an energy-efficient multiplier accumulator based on a memristive array architecture incorporating both analog and digital circuitries. The analog circuitry is used to full advantage for neural networks, as demonstrated by the spike-timing-dependent plasticity (STDP) in fabricated AlO x /TiO x -based metal-oxide memristive devices. STDP protocols for controlling periodic analog resistance with long-range stability were experimentally verified using a variety of voltage amplitudes and spike timings.

  12. The characteristic patterns of neuronal avalanches in mice under anesthesia and at rest: An investigation using constrained artificial neural networks

    Science.gov (United States)

    Knöpfel, Thomas; Leech, Robert

    2018-01-01

    Local perturbations within complex dynamical systems can trigger cascade-like events that spread across significant portions of the system. Cascades of this type have been observed across a broad range of scales in the brain. Studies of these cascades, known as neuronal avalanches, usually report the statistics of large numbers of avalanches, without probing the characteristic patterns produced by the avalanches themselves. This is partly due to limitations in the extent or spatiotemporal resolution of commonly used neuroimaging techniques. In this study, we overcome these limitations by using optical voltage (genetically encoded voltage indicators) imaging. This allows us to record cortical activity in vivo across an entire cortical hemisphere, at both high spatial (~30um) and temporal (~20ms) resolution in mice that are either in an anesthetized or awake state. We then use artificial neural networks to identify the characteristic patterns created by neuronal avalanches in our data. The avalanches in the anesthetized cortex are most accurately classified by an artificial neural network architecture that simultaneously connects spatial and temporal information. This is in contrast with the awake cortex, in which avalanches are most accurately classified by an architecture that treats spatial and temporal information separately, due to the increased levels of spatiotemporal complexity. This is in keeping with reports of higher levels of spatiotemporal complexity in the awake brain coinciding with features of a dynamical system operating close to criticality. PMID:29795654

  13. Aplicação de gorduras "low trans" à base de soja, formuladas utilizando rede neural artificial, em biscoitos laminados

    OpenAIRE

    Alessandra Afonso Teixeira Penteado

    2012-01-01

    Resumo: Após as crescentes divulgações na mídia dos malefícios à saúde causados pela ingestão de gorduras trans e a Resolução RDC 360, de 23 de dezembro de 2003, que estabelece a obrigatoriedade de declaração dos níveis de gordura trans nos rótulos dos alimentos industrializados, nota-se uma crescente demanda por produtos sem ácidos graxos trans (¿low trans¿). O objetivo principal deste projeto foi aplicar a tecnologia de Redes Neurais Artificiais (RNAs) para a obtenção de blends de gorduras ...

  14. Artificial neural networks for prediction of quality in resistance spot welding; Redes neuronales artificiales para la prediccion de la calidad en soldadura por resistencia por puntos

    Energy Technology Data Exchange (ETDEWEB)

    Martin, O.; Lopez, M.; Martin, F.

    2006-07-01

    An artificial neural network is proposed as a tool for predicting from three parameters (weld time, current intensity and electrode sort) if the quality of a resistance spot weld reaches a certain level or not. The quality is determined by cross tension testing. The fact of reaching this quality level or not is the desired output that goes with each input of the artificial neural network during its supervised learning. The available data set is made up of input/desired output pairs and is split randomly into a training subset (to update synaptic weight values) and a validation subset (to avoid overfitting phenomenon by means of cross validation). (Author) 44 refs.

  15. Operant Conditioning: A Minimal Components Requirement in Artificial Spiking Neurons Designed for Bio-Inspired Robot’s Controller

    Directory of Open Access Journals (Sweden)

    André eCyr

    2014-07-01

    Full Text Available We demonstrate the operant conditioning (OC learning process within a basic bio-inspired robot controller paradigm, using an artificial spiking neural network (ASNN with minimal component count as artificial brain. In biological agents, OC results in behavioral changes that are learned from the consequences of previous actions, using progressive prediction adjustment triggered by reinforcers. In a robotics context, virtual and physical robots may benefit from a similar learning skill when facing unknown environments with no supervision. In this work, we demonstrate that a simple ASNN can efficiently realise many OC scenarios. The elementary learning kernel that we describe relies on a few critical neurons, synaptic links and the integration of habituation and spike-timing dependent plasticity (STDP as learning rules. Using four tasks of incremental complexity, our experimental results show that such minimal neural component set may be sufficient to implement many OC procedures. Hence, with the described bio-inspired module, OC can be implemented in a wide range of robot controllers, including those with limited computational resources.

  16. Data mining utilizando redes neuronales

    OpenAIRE

    Ale, Juan María; Bot, Romina Laura

    2004-01-01

    Las Redes Neuronales son ampliamente utilizadas para tareas relacionadas con reconocimiento de patrones y clasificación. Aunque son clasificadores muy precisos, no son comúnmente utilizadas para Data Mining porque producen modelos de aprendizaje inexplicables. El algoritmo TREPAN extrae hipótesis explicables de una Red Neuronal entrenada. Las hipótesis producidas por el algoritmo se representan con un árbol de decisión que aproxima a la red. Los árboles de decisión extraídos por TREPAN no pue...

  17. A nuclear reactor core fuel reload optimization using Artificial-Ant-Colony Connective Networks; Recarga de reatores nucleares utilizando redes conectivas de colonias de formigas artificiais

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Alan M.M. de; Schirru, Roberto [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear]. E-mail: alan@lmp.ufrj.br; schirru@lmp.ufrj.br

    2005-07-01

    A Pressurized Water Reactor core must be reloaded every time the fuel burnup reaches a level when it is not possible to sustain nominal power operation. The nuclear core fuel reload optimization consists in finding a burned-up and fresh-fuel-assembly pattern that maximizes the number of full operational days. This problem is NP-hard, meaning that complexity grows exponentially with the number of fuel assemblies in the core. Besides that, the problem is non-linear and its search space is highly discontinual and multimodal. In this work a parallel computational system based on Ant Colony System (ACS) called Artificial-Ant-Colony Networks is introduced to solve the nuclear reactor core fuel reload optimization problem. ACS is a system based on artificial agents that uses the reinforcement learning technique and was originally developed to solve the Traveling Salesman Problem, which is conceptually similar to the nuclear fuel reload problem. (author)

  18. Artificial brains. A million spiking-neuron integrated circuit with a scalable communication network and interface.

    Science.gov (United States)

    Merolla, Paul A; Arthur, John V; Alvarez-Icaza, Rodrigo; Cassidy, Andrew S; Sawada, Jun; Akopyan, Filipp; Jackson, Bryan L; Imam, Nabil; Guo, Chen; Nakamura, Yutaka; Brezzo, Bernard; Vo, Ivan; Esser, Steven K; Appuswamy, Rathinakumar; Taba, Brian; Amir, Arnon; Flickner, Myron D; Risk, William P; Manohar, Rajit; Modha, Dharmendra S

    2014-08-08

    Inspired by the brain's structure, we have developed an efficient, scalable, and flexible non-von Neumann architecture that leverages contemporary silicon technology. To demonstrate, we built a 5.4-billion-transistor chip with 4096 neurosynaptic cores interconnected via an intrachip network that integrates 1 million programmable spiking neurons and 256 million configurable synapses. Chips can be tiled in two dimensions via an interchip communication interface, seamlessly scaling the architecture to a cortexlike sheet of arbitrary size. The architecture is well suited to many applications that use complex neural networks in real time, for example, multiobject detection and classification. With 400-pixel-by-240-pixel video input at 30 frames per second, the chip consumes 63 milliwatts. Copyright © 2014, American Association for the Advancement of Science.

  19. A Spray-On Carbon Nanotube Artificial Neuron Strain Sensor for Composite Structural Health Monitoring

    Directory of Open Access Journals (Sweden)

    Gyeongrak Choi

    2016-07-01

    Full Text Available We present a nanocomposite strain sensor (NCSS to develop a novel structural health monitoring (SHM sensor that can be easily installed in a composite structure. An NCSS made of a multi-walled carbon nanotubes (MWCNT/epoxy composite was installed on a target structure with facile processing. We attempted to evaluate the NCSS sensing characteristics and benchmark compared to those of a conventional foil strain gauge. The response of the NCSS was fairly good and the result was nearly identical to the strain gauge. A neuron, which is a biomimetic long continuous NCSS, was also developed, and its vibration response was investigated for structural damage detection of a composite cantilever. The vibration response for damage detection was measured by tracking the first natural frequency, which demonstrated good result that matched the finite element (FE analysis.

  20. Application of Artificial Neural Networks to the Analysis of NORM Samples; Aplicación de las Redes Neuronales al Análisis de Muestras NORM

    Energy Technology Data Exchange (ETDEWEB)

    Moser, H.; Peyrés, V.; Mejuto, M.; García-Toraño, E.

    2015-07-01

    This work describes the application of artificial neural networks (ANNs) to analyze the raw data of gamma-ray spectra of NORM samples and decide if the activity content of a certain nuclide is above or below the exemption limit of 1 Bq/g. The main advantage of using an ANN for this purpose is that for the user no specialized knowledge in the field of gamma-ray spectrometry is necessary. In total a number of 635 spectra consisting of varying activity concentrations, seven different materials and three densities each have been generated by Monte Carlo simulation to provide training material to the ANN. These spectra have been created using the simulation code PENELOPE. Validation was carried out with a number of NORM samples previously characterized by conventional gamma-ray spectrometry with peak fitting.

  1. Spectrometry and dosimetry of isotopic sources of neutrons by means of artificial neural networks; Espectrometria y dosimetria de fuentes isotopicas de neutrones mediante redes neuronales artificiales

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H. R.; Ortiz R, J. M.; Hernandez D, V. M; Martinez B, M. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Gallego, E.; Lorente, A. [Universidad Politecnica de Madrid, Departamento de Ingenieria Nuclear, C/Jose Gutierrez Abascal No. 2, 28006 Madrid (Spain); Barquero, R., E-mail: fermineutron@yahoo.co [Hospital del Rio Hortega, C/Dulzaina No. 2, 47012 Valladolid (Spain)

    2010-09-15

    The artificial neural networks technology has been applied to reconstruct the neutrons spectra of two isotopic sources: {sup 252}Cf, and {sup 241}Am-Be. Also, this technology has been applied to obtain the effective dose, E, and the personal dose equivalents, Hp(10) and environmental, H *(10). To obtain the spectra and the doses only were used the count rates produced in a Bonner Spheres spectrometer with a scintillator of {sup 6}LiI(Eu) of 0.4 {phi} x 0.4 cm{sup 2}. The equivalent environmental dose and the spectra of the sources were also obtained by means of the reconstruction code BUNKIUT. When comparing the results obtained by means of both procedures it was found that they are consistent. (Author)

  2. Application of artificial neural networks on the characterization of radioactive waste drums; Aplicacao de redes neurais artificiais na caracterizacao de tambores de rejeito radioativo

    Energy Technology Data Exchange (ETDEWEB)

    Potiens Junior, Ademar Jose; Hiromoto, Goro, E-mail: apotiens@ipen.b, E-mail: hiromoto@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-10-26

    The methodology consist of system simulation of drum-detector by Monte Carlo for obtention of counting efficiency. The obtained data were treated and a neural artificial network (RNA) were constructed for evaluation of total activity of drum. For method evaluation measurements were performed in ten position parallel to the drum axis and the results submitted to the RNA. The developed methodology showed to be effective for isotopic characterization of gamma emitter radioactive wastes distributed in a heterogeneous way in a 200 litters drum. The objective of this work as to develop a methodology of analyse for quantification and localization of radionuclides not homogeneous distributed in a 200 liters drum based on the mathematical techniques

  3. Modern drug design: the implication of using artificial neuronal networks and multiple molecular dynamic simulations

    Science.gov (United States)

    Yakovenko, Oleksandr; Jones, Steven J. M.

    2018-01-01

    We report the implementation of molecular modeling approaches developed as a part of the 2016 Grand Challenge 2, the blinded competition of computer aided drug design technologies held by the D3R Drug Design Data Resource (https://drugdesigndata.org/). The challenge was focused on the ligands of the farnesoid X receptor (FXR), a highly flexible nuclear receptor of the cholesterol derivative chenodeoxycholic acid. FXR is considered an important therapeutic target for metabolic, inflammatory, bowel and obesity related diseases (Expert Opin Drug Metab Toxicol 4:523-532, 2015), but in the context of this competition it is also interesting due to the significant ligand-induced conformational changes displayed by the protein. To deal with these conformational changes we employed multiple simulations of molecular dynamics (MD). Our MD-based protocols were top-ranked in estimating the free energy of binding of the ligands and FXR protein. Our approach was ranked second in the prediction of the binding poses where we also combined MD with molecular docking and artificial neural networks. Our approach showed mediocre results for high-throughput scoring of interactions.

  4. LAS REDES NEURONALES Y LA EVALUACIÓN DEL RIESGO DE CRÉDITO

    Directory of Open Access Journals (Sweden)

    Fredy Ocaris Pérez Ramírez

    2007-01-01

    Full Text Available A pesar del escepticismo del mundo académico sobre los avances de la inteligencia artificial, las redes neuronales han abierto un campo de exploración bursátil que aún tiene mucho por investigar. Atendiendo a las ventajas del uso de las redes neuronales artificiales (ANN, por sus siglas en inglés y a su capacidad para estimar modelos no lineales, en este artículo se muestra la aplicación de las redes neuronales a la cuantificación del riesgo de crédito. Además, se hace el desarrollo teórico de los fundamentos básicos de las redes neuronales. Para presentar las metodologías de medición de riesgo de crédito basados en redes neuronales, y aplicarlas a la base de datos de una cartera comercial, fue necesario elaborar un análisis exploratorio de cada una de las variables e investigar la correlación entre ellas. El objetivo del análisis es encontrar algunas relaciones para grupos determinados de la población, de acuerdo con sus características particulares. Por tanto, se cruzan variables de cada cliente, del crédito y del comportamiento contra la variable default (fallidos y no fallidos. Variable que establece un procedimiento de clasificación, y permite determinar las ponderaciones necesarias y, además, establece la probabilidad de fallido.In spite of the skepticism of the academic world on the advances of artificial intelligence, the neuronal networks have opened up a field of stock-exchange exploration that has still so much to research. Upon expounding the advantages of the usage of artificial neuronal network (ANN and its capacity to estimate nonlinear models this article shows the application of the neuronal networks on the quantification of the credit risk. Furthermore, the article carries out a theoretical development of the basic foundations of neuronal networks. In order to present the methodologies of measurements of credit risk, based upon the neuronal networks and to apply the to the data base of a commercial

  5. Empirical modeling of a dewaxing system of lubricant oil using Artificial Neural Network (ANN); Modelagem empirica de um sistema de desparafinacao de oleo lubrificante usando redes neurais artificiais

    Energy Technology Data Exchange (ETDEWEB)

    Fontes, Cristiano Hora de Oliveira; Medeiros, Ana Claudia Gondim de; Silva, Marcone Lopes; Neves, Sergio Bello; Carvalho, Luciene Santos de; Guimaraes, Paulo Roberto Britto; Pereira, Magnus; Vianna, Regina Ferreira [Universidade Salvador (UNIFACS), Salvador, BA (Brazil). Dept. de Engenharia e Arquitetura]. E-mail: paulorbg@unifacs.br; Santos, Nilza Maria Querino dos [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)]. E-mail: nilzaq@petrobras.com.br

    2003-07-01

    The MIBK (m-i-b-ketone) dewaxing unit, located at the Landulpho Alves refinery, allows two different operating modes: dewaxing ND oil removal. The former is comprised of an oil-wax separation process, which generates a wax stream with 2 - 5% oil. The latter involves the reprocessing of the wax stream to reduce its oil content. Both involve a two-stage filtration process (primary and secondary) with rotative filters. The general aim of this research is to develop empirical models to predict variables, for both unit-operating modes, to be used in control algorithms, since many data are not available during normal plant operation and therefore need to be estimated. Studies have suggested that the oil content is an essential variable to develop reliable empirical models and this work is concerned with the development of an empirical model for the prediction of the oil content in the wax stream leaving the primary filters. The model is based on a feed forward Artificial Neural Network (ANN) and tests with one and two hidden layers indicate very good agreement between experimental and predicted values. (author)

  6. Determination of the influence of the variation of reducing and non-reducing sugars on coffee quality with use of artificial neural network Determinação da influência da variação de açúcar redutor e não redutor na qualidade da bebida do café com utilização de rede neural artificial

    Directory of Open Access Journals (Sweden)

    José A. T. Messias

    2012-04-01

    Full Text Available The present study aimed at evaluating the use of Artificial Neural Network to correlate the values resulting from chemical analyses of samples of coffee with the values of their sensory analyses. The coffee samples used were from the Coffea arabica L., cultivars Acaiá do Cerrado, Topázio, Acaiá 474-19 and Bourbon, collected in the southern region of the state of Minas Gerais. The chemical analyses were carried out for reducing and non-reducing sugars. The quality of the beverage was evaluated by sensory analysis. The Artificial Neural Network method used values from chemical analyses as input variables and values from sensory analysis as output values. The multiple linear regression of sensory analysis values, according to the values from chemical analyses, presented a determination coefficient of 0.3106, while the Artificial Neural Network achieved a level of 80.00% of success in the classification of values from the sensory analysis.Este trabalho teve como objetivo avaliar a utilização de Rede Neural Artificial para correlacionar os valores resultantes de análises químicas de amostras de café com os valores de sua análise sensorial. As amostras de café utilizadas foram referentes ao café Coffea arabica L., cultivar Acaiá do Cerrado, Topázio, Acaiá 474-19 e Bourbon, coletados na região sul de Minas Gerais. As análises químicas foram de açúcar não redutor e açúcar redutor, sendo a qualidade da bebida avaliada pela análise sensorial. O método de Rede Neural Artificial utilizou os valores das análises químicas como variáveis de entrada e os valores da análise sensorial como valores de saída. A regressão linear múltipla dos valores de análise sensorial, em função dos valores das análises químicas, teve coeficiente de determinação de 0,3106, enquanto o método de Rede Neural Artificial empregado obteve um nível de acerto na classificação dos valores da análise sensorial de 80,00%.

  7. Seguridad en redes WLAN

    OpenAIRE

    Muñoz Villa, Diego Geovanny

    2006-01-01

    En nuestro medio es común ver que cada vez se implementan más redes inalámbricas (WLAN), en las empresas como complemento de las redes Lan. Las redes WLAN actualmente son una alternativa real y económica para implementar una red de computadores, sus características de flexibilidad, movilidad, adaptabilidad, y facilidad de instalación han sido la razón, para su buena aceptación en el mercado lo que ha producido una disminución en los costos de estos equipos. Pero sin embargo pocas personas ...

  8. Intensidad exportadora e interacción entre fortalezas del marketing mix: un análisis basado en redes neuronales artificiales || Export Intensity and Interaction between Marketing Mix: An Analysis based on Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    Gutiérrez-Villar, Belén

    2014-12-01

    Full Text Available Entre los factores determinantes de la actuación exportadora de las empresas, numerosos estudios han subrayado la relevancia del mix de marketing. Generalmente, la mayoría de los estudios abordan el análisis de las variables centrado en estrategias específicas, en particular fenómenos de estandarización-adaptación. El presente estudio analiza si existe un efecto interactivo de fortalezas generadas en las diferentes variables del mix de marketing que pueda asociarse a diferentes perfiles exportadores. Para ello, se ha empleado el algoritmo Extreme Learning Machine (ELM dentro de los procedimientos Perceptrón Multicapa (MLP de Redes Neuronales Artificiales (RNA. Asimismo, el análisis se combina con un novedoso procedimiento de análisis de sensibilidad desarrollado ad hoc para este estudio, el cual permite conocer los efectos individuales e interactivos de las variables predictoras sobre la variable dependiente en problemas clasificatorios de naturaleza dicotómica. Los resultados obtenidos nos permiten corroborar la existencia de los efectos interactivos postulados, poniendo al mismo tiempo de manifiesto la utilidad de las RNA y del análisis de sensibilidad propuesto para la investigación en el área de marketing y, específicamente, para los estudios de internacionalización de empresas. || Among the determining factors in export activity, many studies have highlighted the relevance of the marketing mix. Generally, the majority of them use a variables analysis to focus on specific strategies, in particular, standardized-adaptations. This paper analyzes if there is an interactive effect of strength generated in different variables of the marketing mix that can be associated with different export profiles. The Extreme Learning Machine (ELM algorithm has been used within the Multilayer Perceptron (MLP of Artificial Neural Networks (ANN. In addition, the analyses combine a novel approach for sensitivity analysis developed ad hoc for this

  9. Redes neuronales artificiales para el análisis de componentes principales. La red de OJA

    Directory of Open Access Journals (Sweden)

    Piedad Tolmos Rodríguez-Piñero

    2000-01-01

    Full Text Available El análisis de componentes principales es una herramienta estadísticomatemática de gran utilidad en multitud de campos, especialmente en el de la compresión de datos. En este artículo se estudia el proceso de la extracción de componentes principales, y se detalla una Red Neuronal Artificial, la red de Oja, diseñada específicamente para el cálculo de la primera componente principal de la matriz de momentos de segundo orden asociada al vector de datos. Se concluye exponiendo algunas redes que generalizan la red de Oja, y permiten extraer el número deseado de componentes principales. Finalmente se explican algunas aplicaciones, fundamentalmente la del procesamiento de imágenes, y la compresión de datos.

  10. Composicion de redes ambientales a partir de la calidad de servicio

    OpenAIRE

    Palleja Muñoz, Angel; Barba Martí, Antonio

    2009-01-01

    Las redes ambientales definen una iniciativa europea para la cuarta generación de omunicaciones móviles. En esos entornos, la composición de redes heterogéneas para posibilitar comunicaciones con calidad de servicio es un tema fundamental. En este artículo se presenta una propuesta para el diseño de composiciones basándose en el uso de técnicas de inteligencia artificial. Esta ubicuidad se proporciona mediante la omposición de redes ambientales se realiza mediante redes neuronales, algoritm...

  11. Rede neural artificial aplicada à previsão de vazão da Bacia Hidrográfica do Rio Piancó Artificial neural network applied to the forecast of streamflow in the Piancó River Basin

    Directory of Open Access Journals (Sweden)

    Wanderson dos S. Sousa

    2010-02-01

    Full Text Available A previsão de vazão em um sistema hídrico não é apenas uma das técnicas utilizadas para minimizar o impacto das incertezas do clima sobre o gerenciamento dos recursos hídricos mas, também, um dos principais desafios relacionados ao conhecimento integrado da climatologia e da hidrologia de uma bacia hidrográfica. O objetivo deste trabalho foi modelar a relação não-linear entre chuva e vazão na bacia hidrográfica do rio Piancó, no semiárido paraibano, através da técnica de Redes Neurais Artificiais (RNA. Aqui se avaliou a capacidade da RNA modelar o processo chuva-vazão em base mensal e se considerou, durante o seu treinamento, a influência da arquitetura da rede e da inicialização dos pesos. No final do treinamento foi escolhida a melhor arquitetura para modelar vazões médias mensais na bacia estudada, com base no desempenho do modelo. A arquitetura de RNA que produziu melhor resultado foi a RC315L, com valores para o coeficiente de determinação, de eficiência e erro padrão da estimativa de 92,0, 77,0% e 8,29, respectivamente.Streamflow forecasting in a water system is one of the techniques used to reduce the impact of the uncertainties of the climate on administration of the water resources. That technique can be considered as one of the principal challenges related to the integrated knowledge of the climatology and of the hydrology of the river basin. The aim of this work was to model the non-linear relationship between rainfall and streamflow in the Piancó River Basin, in the Paraíba semiarid, using the technique of Artificial Neural Networks (ANN. Here the ability of ANN was evaluated to model the rainfall-runoff process on a monthly basis. During training of the ANN, the network architecture and weights initialization influence were considered. At the end of the training the best architecture was chosen, to model the streamflow monthly mean in the studied basin, based upon the performance of the model. The ANN

  12. Detecção e classificação de curto-circuitos em sistemas de distribuição usando rede neural artificial ARTMAP nebulosa

    OpenAIRE

    Martins, João Roberto Deroco [UNESP

    2010-01-01

    Este trabalho apresenta uma metodologia para detecção e classificação de faltas do tipo curto-circuito. Esta operação de diagnóstico tem como principal operador um banco de redes neurais artificiais (RNAs) do tipo ARTMAP Nebulosa. Tal ferramenta segue a principal filosofia das RNAs: o reconhecimento de padrões, através de um trei- namento supervisionado inicial, responsável por atualizar os parâmetros das redes con- comitantemente com os resultados desejados. Finalizada a fase de adaptação, a...

  13. Uma abordagem híbrida baseada em casos e redes neurais. Uma aplicação: escolha e configuração de modelos de redes neurais

    OpenAIRE

    Ricardo Barz Sovat

    2002-01-01

    Nesta tese, é pesquisada a integração entre dois paradigmas da área de Inteligência Artificial, Raciocínio Baseado em Casos e Redes Neurais Artificiais. Essa pesquisa dá-se em dois sentidos. Primeiro, o estudo da aplicação da metodologia de Raciocínio Baseado em Casos ao problema da escolha e configuração de um modelo de Rede Neural Artificial. Em segundo lugar, a viabilidade da introdução de uma Rede Neural Artificial no interior do ciclo de funcionamento de um sistema baseado em casos. As s...

  14. Genetic algorithms used to optimize an artificial neural network design used in neutron spectrometry; Algoritmos geneticos utilizados para optimizar un diseno de red neuronal artificial usado en espectrometria de neutrones

    Energy Technology Data Exchange (ETDEWEB)

    Arteaga A, T.; Ortiz R, J. M.; Vega C, H. R., E-mail: tarcicio70@yahoo.co.uk [Universidad Autonoma de Zacatecas, Av. Lopez Velarde 117, 98600 Zacatecas, Zac. (Mexico)

    2016-10-15

    Artificial neural networks (Ann) are widely used; it which consist of an input layer, one or more hidden layers and an output layer; these layers contain neurons and each has connections called weights, where the knowledge are allowed and let to Ann solve problems proposed. These Ann is used to reconstruction of the energy spectrum of neutrons from count rates and develop Bonner sphere neutron dosimetry. Currently, we have developed Ann with high performance and generalization ability. Determine your optimal architecture is usually a difficult task, an exhaustive search of all possible combinations of parameters is rarely possible further training of the neural network with random initial weights can cause two major drawbacks: it can stuck in local minima or converge very slowly. In this project it will be used Genetic Algorithms (Ga); which are based on the principle or analogy of evolution through natural selection and has shown to be very effective in optimizing complex search functions and large spaces or to find a near optimal overall efficiency. The aim is to decrease the architecture in number of hidden neurons and therefore the total number of connections is reducing. The benefits obtained by optimizing the network are that the number of connections would be considerably smaller and thus the computational complexity, hardware integration, resources will be lower such that will allow to be even more viable implemented. To use the Ga three problems must be solve: 1) coding the problem into chromosomes. 2) Construct a fitness function. 3) Proper selection of genetic operators; crossover, selection, mutation. As a result, the scientific knowledge obtained can to be applied to similar problems having a reference parameters used and their impact on the optimization would to be generated. It concluded that the input layer and output are subject to the problem; the Ga propose the optimal number of neurons in the hidden layer without losing the quality of the

  15. Ajuste do modelo de Schumacher e Hall e aplicação de redes neurais artificiais para estimar volume de árvores de eucalipto Adjustment of the Schumacher and Hall model and application of artificial neural networks to estimate volume of eucalypt trees

    Directory of Open Access Journals (Sweden)

    Mayra Luiza Marques da Silva

    2009-12-01

    Full Text Available Objetivou-se, neste trabalho, avaliar o ajuste do modelo volumétrico de Schumacher e Hall por diferentes algoritmos, bem como a aplicação de redes neurais artificiais para estimação do volume de madeira de eucalipto em função do diâmetro a 1,30 m do solo (DAP, da altura total (Ht e do clone. Foram utilizadas 21 cubagens de povoamentos de clones de eucalipto com DAP variando de 4,5 a 28,3 cm e altura total de 6,6 a 33,8 m, num total de 862 árvores. O modelo volumétrico de Schumacher e Hall foi ajustado nas formas linear e não linear, com os seguintes algoritmos: Gauss-Newton, Quasi-Newton, Levenberg-Marquardt, Simplex, Hooke-Jeeves Pattern, Rosenbrock Pattern, Simplex, Hooke-Jeeves e Rosenbrock, utilizado simultaneamente com o método Quasi-Newton e com o princípio da Máxima Verossimilhança. Diferentes arquiteturas e modelos (Multilayer Perceptron MLP e Radial Basis Function RBF de redes neurais artificiais foram testados, sendo selecionadas as redes que melhor representaram os dados. As estimativas dos volumes foram avaliadas por gráficos de volume estimado em função do volume observado e pelo teste estatístico L&O. Assim, conclui-se que o ajuste do modelo de Schumacher e Hall pode ser usado na sua forma linear, com boa representatividade e sem apresentar tendenciosidade; os algoritmos Gauss-Newton, Quasi-Newton e Levenberg-Marquardt mostraram-se eficientes para o ajuste do modelo volumétrico de Schumacher e Hall, e as redes neurais artificiais apresentaram boa adequação ao problema, sendo elas altamente recomendadas para realizar prognose da produção de florestas plantadas.This research aimed at evaluating the adjustment of Schumacher and Hall volumetric model by different algorithms and the application of artificial neural networks to estimate the volume of wood of eucalyptus according to the diameter at breast height (DBH, total height (Ht of the clone. For such, 21 scalings of stands of eucalyptus clones were used with

  16. Use of artificial neuronal networks for prediction of the control parameters in the process of anaerobic digestion with thermal pretreatment.

    Science.gov (United States)

    Flores-Asis, Rita; Méndez-Contreras, Juan M; Juárez-Martínez, Ulises; Alvarado-Lassman, Alejandro; Villanueva-Vásquez, Daniel; Aguilar-Lasserre, Alberto A

    2018-04-19

    This article focuses on the analysis of the behavior patterns of the variables involved in the anaerobic digestion process. The objective is to predict the impact factor and the behavior pattern of the variables, i.e., temperature, pH, volatile solids (VS), total solids, volumetric load, and hydraulic residence time, considering that these are the control variables for the conservation of the different groups of anaerobic microorganisms. To conduct the research, samples of physicochemical sludge were taken from a water treatment plant in a poultry processing factory, and, then, the substrate was characterized, and a thermal pretreatment was used to accelerate the hydrolysis process. The anaerobic digestion process was analyzed in order to obtain experimental data of the control variables and observe their impact on the production of biogas. The results showed that the thermal pre-hydrolysis applied at 90°C for 90 min accelerated the hydrolysis phase, allowing a significant 52% increase in the volume of methane produced. An artificial neural network was developed, and it was trained with the database obtained by monitoring the anaerobic digestion process. The results obtained from the artificial neural network showed that there is an adjustment between the real values and the prediction of validation based on 60 samples with a 96.4% coefficient of determination, and it was observed that the variables with the major impact on the process were the loading rate and VS, with impact factors of 36% and 23%, respectively.

  17. Aplicación de las redes neuronales artificiales para la estratificación de riesgo de mortalidad hospitalaria Application of artificial neural networks for risk stratification of hospital mortality

    Directory of Open Access Journals (Sweden)

    J. Trujillano

    2003-12-01

    Full Text Available Objetivo: Comparar la capacidad de predicción de mortalidad hospitalaria de una red neuronal artificial (RNA con el Acute Physiology and Chronic Health Evaluation II (APACHE II y la regresión logística (RL, y comparar la asignación de probabilidades entre los distintos modelos. Método: Se recogen de forma prospectiva las variables necesarias para el cálculo del APACHE II. Disponemos de 1.146 pacientes asignándose aleatoriamente (70 y 30% al grupo de Desarrollo (800 y al de Validación (346. Con las mismas variables se genera un modelo de RL y de RNA (perceptrón de 3 capas entrenado por algoritmo de backpropagation con remuestreo bootstrap y con 9 nodos en la capa oculta en el grupo de desarrollo. Se comparan los tres modelos en función de los criterios de discriminación con el área bajo la curva ROC (ABC [IC del 95%] y de calibración con el test de Hosmer-Lemeshow C (HLC. Las diferencias entre las probabilidades se valoran con el test de Bland-Altman. Resultados: En el grupo de validación, el APACHE II con ABC de 0,79 (0,75-0,84 y HLC de 11 (p = 0,329; modelo RL, ABC de 0,81 (0,76-0,85 y HLC de 29 (p = 0,0001, y en RNA, ABC de 0,82 (0,77-0,86 y HLC de 10 (p = 0,404. Los pacientes con mayores diferencias en la asignación de probabilidad entre RL y RN (8% del total son pacientes con problemas neurológicos. Los peores resultados se obtienen en los pacientes traumáticos (ABC inferior a 0,75 en todos los modelos. En los pacientes respiratorios, la RNA alcanza los mejores resultados (ABC = 0,87 [0,78-0,91]. Conclusiones: Una RNA es capaz de estratificar el riesgo de mortalidad hospitalaria utilizando las variables del sistema APACHE II. La RNA consigue mejores resultados frente a RL, sin alcanzar significación, ya que no trabaja con restricciones lineales ni de independencia de variables, con una diferente asignación de probabilidad individual entre los modelos.Objective: To compare the ability of an artificial neural network (ANN to

  18. REDES SOCIALES Y POBREZA

    Directory of Open Access Journals (Sweden)

    Camilo Madariaga Orozco

    2000-01-01

    Full Text Available El ser humano tiene una gran capacidad de adaptarse y transformar las condiciones ambientales para vivir de mejor forma, aun en las situacines más adversas. Estos procesos de transmisión de conocimiento son pasados de generación en generación y se constituyen en el principal mecanismo de adaptación de la especie humana; cada cultura crea un estilo de vida que permite a sus integrantes sobrevivir y reproducirse en un entorno particular. En los ambientes de pobreza, a través de los años de investigaciones que hemos terminado en el marco del Centro de investigaciones en Desarrolo Humano, las redes sociales ha sido uno de los mecanismos más acertados e interesantes que los pobladores de las comunidades pobres practican para superar sus problemas. Producto de las investigaciones hemos hecho un análisis específico de cómo se comportan las redes en esos ambientes de pobreza crítica.

  19. Introduction to Concepts in Artificial Neural Networks

    Science.gov (United States)

    Niebur, Dagmar

    1995-01-01

    This introduction to artificial neural networks summarizes some basic concepts of computational neuroscience and the resulting models of artificial neurons. The terminology of biological and artificial neurons, biological and machine learning and neural processing is introduced. The concepts of supervised and unsupervised learning are explained with examples from the power system area. Finally, a taxonomy of different types of neurons and different classes of artificial neural networks is presented.

  20. Redes inalámbricas

    OpenAIRE

    Pérez Quintero, Edwin Alejandro

    2008-01-01

    Este módulo proporciona una introducción a las redes inalámbricas en general y a las redes inalámbricas de área local en particular. Describe y explica lo que son las diferentes tecnologías inalámbricas, sus principales características, problemas de seguridad, ventajas, desventajas y usos o aplicaciones.

  1. An artificial neural network strategy for monitoring of gas/oil systems in slug flow pattern; Aplicacao de redes neurais artificiais no monitoramento do escoamento de sistemas gas/oleo em regime de golfadas

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, Fernando H.B. [Universidade Tiradentes (UNIT), Aracaju, SE (Brazil). Instituto de Tecnologia e Pesquisa; Universidade Federal de Campina Grande (UFCG), PB (Brazil); Silva, Rosivania P.; Fortuny, Montserrat; Santos, Alexandre F. [Universidade Tiradentes (UNIT), Aracaju, (Brazil). Instituto de Tecnologia e Pesquisa; Nunes, Giovani C. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2008-07-01

    In the petroleum industry, the design of multiphase production systems requires an accurate estimation of the gas-oil ratio (GOR) in the transporting pipelines. However, existing GOR estimation methods are often inadequate in terms of desired accuracy and application range, due to the complex phase distributions and the wide range of fluid properties encountered in production operations. In this paper, the effectiveness of using artificial neural networks in determining GOR values is evaluated, proving to be a reasonable way to monitor this property during oil transportation. (author)

  2. Análise computacional para auxílio ao diagnóstico de osteoartrite de coluna lombar baseado em redes neurais artificiais Computational analysis based on artificial neural networks for aiding in diagnosing osteoarthritis of the lumbar spine

    Directory of Open Access Journals (Sweden)

    Carlos Cassiano Denipotti Veronezi

    2011-04-01

    Full Text Available OBJETIVOS: Conhecer as vantagens da utilização das redes neurais artificiais no reconhecimento de padrões em radiografias de coluna lombar na incidência perfil para auxiliar no diagnóstico da osteoartrite primária. MÉTODO: Estudo transversal, descritivo, analítico, de abordagem quantitativa e com ênfase diagnóstica. O conjunto de treinamento foi composto por imagens coletadas no período de janeiro a julho de 2009 de pacientes submetidos a radiografias digitais de coluna lombar na incidência em perfil provenientes de um serviço de radiologia localizado no município de Criciúma (SC. Das 260 imagens coletadas, foram excluídas: as radiografias distorcidas, as patologias que alteram a arquitetura da coluna lombar e os padrões de difícil caracterização, resultando em um total de 206 imagens. O banco de imagens (n = 206 foi subdividido, resultando em 68 radiografias para a etapa de treinamento, 68 para testes e 70 para validação. Foi utilizada uma rede neural híbrida baseada em mapas auto-organizáveis de Kohonen e redes Multilayer Perceptron. RESULTADOS: Após 90 ciclos, foi realizada a validação com o melhor teste, alcançando acurácia de 62,85%, sensibilidade de 65,71% e especificidade de 60%. CONCLUSÃO: Apesar da demonstração de uma eficácia mediana, por se tratar de estudo de caráter inovador, seus valores mostram um futuro promissor da técnica utilizada, com sugestão para trabalhos futuros com abrangência na metodologia de processamento das imagens e ciclos com uma quantidade maior de radiografias.OBJECTIVE: To ascertain the advantages of applying artificial neural networks to recognize patterns on lumbar column radiographs in order to aid in the process of diagnosing primary osteoarthritis. METHODS: This was a cross-sectional descriptive analytical study with a quantitative approach and an emphasis on diagnosis. The training set was composed of images collected between January and July 2009 from patients who had

  3. Identificación del estado de madurez de las frutas con redes neuronales artificiales, una revisión

    Directory of Open Access Journals (Sweden)

    Gustavo Andrés Figueredo-Ávila

    2016-01-01

    Full Text Available La aplicación de las Redes Neuronales Artificiales (RNA y de la visión artificial tiene cada vez más acogida en la industria de productos alimenticios; estas técnicas priorizan la clasificación, el reconocimiento de patrones y la predicción de las cosechas y de los cambios físicos de sus productos. En este artículo se define el concepto de red neuronal y se describen sus principales características y modelos, y, por otro lado, se define el concepto de procesamiento de imágenes digitales y las diferentes etapas que lo componen. Complementariamente, se exponen las generalidades de la inspección de frutas (enfocada en Colombia y sus técnicas. Finalmente, se especifican diferentes trabajos en los que se aplicaron técnicas de RNA y visión artificial en el campo de los productos alimenticios, dispuestos por áreas de  aplicación, y se identifica de manera concluyente el impacto que estas dos técnicas tienen para la clasificación, el reconocimiento de patrones y la predicción en el sector de productos alimenticios.

  4. Design of an artificial neural network, with the topology oriented to the reconstruction of neutron spectra; Diseno de una red neuronal artificial, con la topologia orientada a la reconstruccion del espectro de neutrones

    Energy Technology Data Exchange (ETDEWEB)

    Arteaga A, T.; Ortiz R, J.M.; Vega C, H.R.; Hernandez D, V.M.; Manzanares A, E.; Mercado S, G.A. [Unidades Academicas de Estudios Nucleares, Ingenieria Electrica y Matematicas, Universidad de Zacatecas, A.P. 336, 98000 Zacatecas (Mexico)]. e-mail: tarcicio70@yahoo.co.uk

    2006-07-01

    People that live in high places respect to the sea level, in latitudes far from the equator or that they travel by plane, they are exposed to atmospheres of high radiation generated by the cosmic rays. Another atmosphere with radiation is the medical equipment, particle accelerators and nuclear reactors. The evaluation of the biological risk for neutron radiation requires an appropriate and sure dosimetry. A commonly used system is the Bonner Sphere Spectrometer (EEB) with the purpose of reconstructing the spectrum that is important because the equivalent dose for neutrons depends strongly on its energy. The count rates obtained in each sphere are treated, in most of the cases, for iterative methods, Monte Carlo or Maximum Entropy. Each one of them has difficulties that it motivates to the development of complementary procedures. Recently it has been used Artificial Neural Networks, ANN) and not yet conclusive results have been obtained. In this work it was designed an ANN to obtain the neutron energy spectrum neutrons starting from the counting rate of count of an EEB. The ANN was trained with 129 reference spectra obtained of the IAEA (1990, 2001), 24 were built as defined energy, including isotopic sources of neutrons of reference and operational, of accelerators, reactors, mathematical functions, and of defined energy with several peaks. The spectrum was transformed from lethargy units to energy and were reaccommodated in 31 energies using the Monte Carlo code 4C. The reaccommodated spectra and the response matrix UTA4 were used to calculate the prospective count rates in the EEB. These rates were used as entrance and its respective spectrum was used as output during the net training. The net design is Retropropagation type with 5 layers of 7, 140, 140, 140 and 31 neurons, transfer function logsig, tansig, logsig, logsig, logsig respectively. Training algorithm, traingdx. After the training, the net was proven with a group of training spectra and others that

  5. A tabela periódica dos elementos químicos prevista por redes neurais artificiais de Kohonen Periodic table of the elements in the perspective of artificial neural networks

    Directory of Open Access Journals (Sweden)

    Maurício Ruv Lemes

    2008-01-01

    Full Text Available Although several chemical elements were not known by end of the 18th century, Mendeleyev came up with an astonishing achievement: the periodic table of elements. He was not only able to predict the existence of (then new elements but also to provide accurate estimates of their chemical and physical properties. This is certainly a relevant example of the human intelligence. Here, we intend to shed some light on the following question: Can an artificial intelligence system yield a classification of the elements that resembles, in some sense, the periodic table? To achieve our goal, we have fed a self-organized map (SOM with information available at Mendeleyev's time. Our results show that similar elements tend to form individual clusters. Thus, SOM generates clusters of halogens, alkaline metals and transition metals that show a similarity with the periodic table of elements.

  6. A methodology for extracting knowledge rules from artificial neural networks applied to forecast demand for electric power; Uma metodologia para extracao de regras de conhecimento a partir de redes neurais artificiais aplicadas para previsao de demanda por energia eletrica

    Energy Technology Data Exchange (ETDEWEB)

    Steinmetz, Tarcisio; Souza, Glauber; Ferreira, Sandro; Santos, Jose V. Canto dos; Valiati, Joao [Universidade do Vale do Rio dos Sinos (PIPCA/UNISINOS), Sao Leopoldo, RS (Brazil). Programa de Pos-Graduacao em Computacao Aplicada], Emails: trsteinmetz@unisinos.br, gsouza@unisinos.br, sferreira, jvcanto@unisinos.br, jfvaliati@unisinos.br

    2009-07-01

    We present a methodology for the extraction of rules from Artificial Neural Networks (ANN) trained to forecast the electric load demand. The rules have the ability to express the knowledge regarding the behavior of load demand acquired by the ANN during the training process. The rules are presented to the user in an easy to read format, such as IF premise THEN consequence. Where premise relates to the input data submitted to the ANN (mapped as fuzzy sets), and consequence appears as a linear equation describing the output to be presented by the ANN, should the premise part holds true. Experimentation demonstrates the method's capacity for acquiring and presenting high quality rules from neural networks trained to forecast electric load demand for several amounts of time in the future. (author)

  7. Redes sociais e conflito organizacional

    OpenAIRE

    Lima, Jorge Ávila de

    2016-01-01

    As organizações são redes sociais cujos membros estabelecem entre si ligações de diversos tipos, formais e informais, positivas e negativas. O conflito entre atores é um processo comum que pode ser explicado com base num conjunto diverso de fatores. Contudo, o conflito interno às organizações tem sido pouco estudado, numa perspetiva de redes sociais. Para além disto, o conflito interorganizacional, analisado ao nível dos atores individuais, tem sido ainda menos estudado. No presente artigo, p...

  8. Efectividad en las redes empresariales

    OpenAIRE

    Álvarez Rey, Natalia; Correal López, Ana María; García Algarra, Laura Ximena

    2014-01-01

    Este estudio tiene como objetivo identificar cuáles son las variables que repercuten en la efectividad de las redes empresariales. Esto, con base en la búsqueda de literatura existente de la efectividad en equipos, en organizaciones y en las redes interorganizacionales, así como el análisis de modelos y estudios empíricos que permitieron el análisis. De acuerdo con la búsqueda, se encontró que variables como la estructura de la red, la estabilidad del sistema, el compromiso de los empleados e...

  9. Geração de Isolinhas, com dados obtidos por levantamento GPS/L1L2, mediante a técnica de Redes Neurais Artificiais = Generation of Isolines using GPS/L1L2 data and Artificial Neural Network technique

    Directory of Open Access Journals (Sweden)

    Elaine Cristine Barros de Souza

    2006-07-01

    Full Text Available O objetivo deste trabalho é mostrar uma alternativa para o processo deinterpolação empregado em Modelagem Digital do Terreno. Utilizando-se dados de levantamentos GPS coletados por meio de posicionamento relativo cinemático realizou-se um processo de interpolação por meio de Redes Neurais Artificiais (RNA. Os resultados foram comparados com os dados obtidos usando-se o algoritmo de interpolação Inverso doQuadrado de uma Distância (IQD para avaliar o comportamento das grades geradas por meio de análises qualitativas (isolinhas e MDT e quantitativas (resíduos. Conclui-se que o método testado é viável se comparado com o algoritmo IQD e, portanto, o uso de RNA apresenta-se adequado para a interpolação de dados GPS provenientes do processamento de fase das portadoras L1 e L2.The objective of this work is to show an alternative for theinterpolation process used in Digital Terrain Modeling. GPS surveying data of a kinematic relative positioning were interpolated by means of Artificial Neural Networks (ANN algorithm. The performance of the generated gridding was compared to the Inverse Square Distance interpolation algorithm data by means of qualitative (isolines and DTM and quantitative (residuals analyses. In conclusion, the tested method is viable if compared to the algorithm Inverse of the Square of a Distance. Therefore, the use of ANN is suitable for the interpolation of GPS data obtained from the L1 and L2 carriers phase processing.

  10. Artificial neural network based model to calculate the environmental variables of the tobacco drying process; Modelo basado en redes neuronales artificiales para el cálculo de parámetros ambientales en el proceso de curado del tabaco

    Directory of Open Access Journals (Sweden)

    Víctor Martínez-Martínez

    2013-06-01

    Full Text Available This paper presents an Artificial Neural Network (ANN based model for environmental variables related to the tobacco drying process. A fitting ANN was used to estimate and predict temperature and relative humidity inside the tobacco dryer: the estimation consists of calculating the value of these variables in different locations of the dryer and the prediction consists of forecasting the value of these variables with different time horizons. The proposed model has been validated with temperature and relative humidity data obtained from a real tobacco dryer using a Wireless Sensor Network (WSN. On the one hand, an error under 2% was achieved, obtaining temperature as a function of temperature and relative humidity in other locations in the estimation task. Besides, an error around 1.5 times lower than the one obtained with an interpolation method was achieved in the prediction task when the temperature inside the tobacco mass was predicted with time horizons over 2.5 hours as a function of its present and past values. These results show that ANN-based models can be used to improve the tobacco drying process because with these types of models the value of environmental variables can be predicted in the near future and can be estimated in other locations with low errors.

  11. Optimization of artificial neural networks for the reconstruction of the neutrons spectrum and their equivalent doses; Optimizacion de redes neuronales artificiales para la reconstruccion del espectro de neutrones y sus dosis equivalentes

    Energy Technology Data Exchange (ETDEWEB)

    Reyes A, A.; Ortiz R, J. M.; Reyes H, A.; Castaneda M, R.; Solis S, L. O.; Vega C, H. R., E-mail: art8291@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Ingenieria Electrica, Av. Lopez Velarde No. 801, Col. Centro, 98000 Zacatecas (Mexico)

    2014-08-15

    In this work was used the robust design methodology of artificial neural networks to determine a good topology of net able to solve with efficiency the problems of neutrons spectrometry and dosimetry. For the design of the topology of optimized net 36 different net architectures based on an orthogonal arrangement with a configuration L{sub 9}(3{sup 4}), L{sub 4}(3{sup 2}) were trained. For the training of the neural networks, was used a computer code developed in the ambient of Mat lab programming, which automates the process and analysis of the information, reducing the time used in this activity considerably for the investigator. For the training of the propagation nets forward was utilized a neutrons spectrum compendium published by the International Atomic Energy Agency, where of the total 80% was used for the training and 20% for the test, it trained with an inverse propagation algorithm being the entrance data the count rates corresponding to the 7 spheres of the spectrometric system of Bonner spheres, as exit data, the neural network obtains the neutrons spectrum expressed in 60 energy groups and are calculated of simultaneous way 15 dosimetric quantities. (Author)

  12. Artificial neural networks applied to the prediction of spot prices in the market of electric energy; Redes neurais artificiais aplicadas na previsao de precos spot no mercado de energia eletrica

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Alcantaro Lemes; Grimoni, Jose Aquiles Baesso [Univesidade de Sao Paulo (USP), SP (Brazil). Inst. de Eletrotecnica e Energia], emails: alcantaro@iee.usp.br, aquiles@iee.usp.br

    2010-07-01

    The commercialization of electricity in Brazil as well as in the world has undergone several changes over the past 20 years. In order to achieve an economic balance between supply and demand of the good called electricity, stakeholders in this market follow both rules set by society (government, companies and consumers) and set by the laws of nature (hydrology). To deal with such complex issues, various studies have been conducted in the area of computational heuristics. This work aims to develop a software to forecast spot market prices in using artificial neural networks (ANN). ANNs are widely used in various applications especially in computational heuristics, where non-linear systems have computational challenges difficult to overcome because of the effect named 'curse of dimensionality'. This effect is due to the fact that the current computational power is not enough to handle problems with such a high combination of variables. The challenge of forecasting prices depends on factors such as: (a) foresee the demand evolution (electric load); (b) the forecast of supply (reservoirs, hydrology and climate), capacity factor; and (c) the balance of the economy (pricing, auctions, foreign markets influence, economic policy, government budget and government policy). These factors are considered be used in the forecasting model for spot market prices and the results of its effectiveness are tested and huge presented. (author)

  13. Qualitative analysis of the maintenance politics of the systems of a typical PWR by artificial neural networks; Analise qualitativa da politica de manutencoes dos sistemas de um PWR tipico por redes neurais artificiais

    Energy Technology Data Exchange (ETDEWEB)

    Lourenco, Victor Hugo Moreno

    2010-02-15

    Proceedings and techniques in order to maximize the reliability and the availability of industrial plants have been used along the last decades by specialists and professionals of maintenance. However, the modem industrial systems' sizing, and the increasing complexity and interdependence among its components have become this activity's planning a more and more difficult task. Considering this scenario, the objective of the present work is to provide a computational tool which is able to help about the taking decision's task, and about planning policies of maintenance practiced in thermonuclear plants. The tool developed is based on the artificial neural networks (ANN) for the recognition of standards and establishment of correlations among events occurred in the components of pressurized water reactor (PWR) typical systems. The ANN work as miners of database of failure events, and are able to identify connections and to establish imperceptible inferences even for the most experienced specialists in maintenance of nuclear systems. The results were attained from realistic data and are confronted against the maintenance's classic policies which are practiced nowadays on PWR thermonuclear plants. These results show the solidity of the technique in valuing and predicting failures in a real power plant, and is able to be used as a tool for supporting decisions about planning maintenance policies on a typical PWR. (author)

  14. Reconocimiento de imágenes utilizando redes neuronales artificiales

    OpenAIRE

    García García, Pedro Pablo

    2013-01-01

    Este trabajo describe el proceso de extracción de patrones característicos de imágenes,mediante la ayuda de Redes Neuronales Artificiales. La información de la Red Neuronal junto con datos adicionales de las imágenes, serán almacenados en una base de datos y consumidos por un servicio web. Un teléfono móvil con sistema operativo Android consumirá la información almacenada en el servicio web. Posteriormente al realizar una captura de imagen con la cámara del teléfono, este procesará la imag...

  15. Processamento da rede neocognitron para reconhecimento facial em ambiente de alto desempenho GPU

    OpenAIRE

    Gustavo Poli Lameirão da Silva

    2007-01-01

    Neste trabalho é apresentada a implementação da Rede Neural Neocognitron, usando uma arquitetura de computação de alto desempenho baseada em GPU (Graphics Processing Unit). O Neocognitron é uma rede neural artificial, proposta por Fukushima e colaboradores, constituída de vários estágios de camadas de neurônios, organizados em matrizes bidimensionais denominadas planos celulares. Para o processamento de alto desempenho da aplicação de reconhecimento facial usando neocognitron foi utilizado o ...

  16. Plan de marketing para la herramienta de inteligencia artificial Parlakuy

    OpenAIRE

    Farro Flores, César Augusto; Gonzales Gaspar, Juan Francisco

    2017-01-01

    Parlakuy es una empresa tecnológica en formación dedicada a utilizar herramientas de inteligencia artificial, específicamente machine learning, en las redes sociales. Tiene por objetivo ayudar a resolver las necesidades de las empresas y personas para que puedan entender a sus clientes en redes sociales, identificar temas importantes para su estudio y tomar acciones preventivas ante un suceso o acontecimiento en tiempo real. Para esto crea la herramienta Parlakuy, que tiene el mismo nombre...

  17. Discriminación entre strain y temperatura en un sistema BOTDA mediante redes neuronales artificiales

    OpenAIRE

    Ruiz Lombera, Rubén; Piccolo, Arianna; Fuentes Cayón, Alberto; López Higuera, José Miguel; Mirapeix Serrano, Jesús María

    2017-01-01

    RESUMEN: En este artículo se propone el uso de un enfoque basado en inteligencia artificial, en particular en redes neuronales artificiales, para conseguir una discriminación automática en medidas de strain y temperatura en sistemas sensores distribuidos basados en la dispersión estimulada de Brillouin en fibra óptica, en particular en implementaciones BOTDA. ABSTRACT: We present in this paper the employment of artificial intelligence, in particular artificial neural networks, as a possibl...

  18. Application of of artificial neural networks for estimation of soil-plant transfer factor for {sup 137}Cs; Aplicacao de redes neurais artificiais para a previsao de valores do fator de transferencia solo-planta para {sup 137}Cs

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Anna Karla Gomes dos

    2016-07-01

    The knowledge of radionuclide behavior in soils is fundamental to calculate the dose due to food ingestion and to evaluate the risks of radioactive exposure of the population. This knowledge associated to the socio-economic characteristics of the affected region will set the radio protective measures to be taken in case of radioactive contamination of rural areas. The soil-plant transfer factor (TF) is the specific parameter value of radiological models to numerically integrate the dynamic processes that occur within the radionuclides in the soil plant system. This measurement, specific to each radionuclide and soil type, is defined ratio between a specific radionuclide activity in the edible part of the plant and its soil activity. However, the absence of linearity between soil concentrations and the measurements in plants indicate the complexity of the transfer process of radionuclide from soil to a plant, making it difficult to forecast the TF ratio in a specific scenario. One of the main radionuclides associated to nuclear accidents impacting rural areas is {sup 137}Cs. This is one of the most worrisome radionuclides because of its physiochemical properties and its chemical similarity with potassium (K) and its extended physical mid-life (t1/2 = 30,17 years) that allows great environmental dispersion, ecological mobility and environmental endurance. Radiological studies related to {sup 137}Cs transfer factor show that pedological parameters that considerably explain the behavior of {sup 137}Cs in soil-plant system are: exchangeable K, clayed minerals, organic matter content and pH in soils. In this work, the computational method of artificial neural network (ANN) was applied to evaluate the possibility to forecast the TF of {sup 137}Cs in cereals, associated to pedological parameters considered potential indicators of its phyto availability: cationic exchange capacity (CEC), exchangeable K and pH. This study demonstrated that the ANN, having only as entry data

  19. Aproximación de los problemas de optimización por redes neuronales artificiales

    Directory of Open Access Journals (Sweden)

    Caballero Fernandez, Rafael

    2001-01-01

    Full Text Available En el presente artículo, pretendemos aportar un conocimiento de cómo puede aproximarse un problema de optimización mediante la dinámica de las redes neuronales artificiales, específicamente mediante las redes de tipo Hopfield. La elección de este tipo de redes radica en el objetivo que nos hemos propuesto en el presente trabajo, la resolución on-line de los problemas de optimización lineal, cuadrática, no lineal y combinatoria. Construimos, desarrollamos y justificamos formalmente una metodología integral que permite recoger los distintos tipos de problemas de optimización y construir una red neuronal de tipo Hopfield que los resuelva de una manera computacionalmente adecuada y formalmente correcta, comparando los resultados obtenidos con los publicados más recientemente.

  20. Redes sociais ganham muito poder

    OpenAIRE

    Propaganda & Marketing

    2015-01-01

    Se a internet já era uma dor de cabeça para mídias de agências e anunciantes descobrirem onde e quando colocar suas campanhas para atingir o público exato, imagine agora, em que as redes sociais contam com veículos fortes que caminham a passos largos para estar entre as líderes do mercado de mísia brasileiro.

  1. Redes sociales y mujeres mayores

    OpenAIRE

    Fernández Campomanes, María

    2012-01-01

    Estudio de carácter cualitativo sobre la influencia de las redes sociales en la mejora de la calidad de vida de las mujeres mayores, que responden al perfil de mujeres de más de 55 años de edad, cuidadoras y cuyo acceso a las TIC no guarda relación con el empleo ni con el ámbito académico.

  2. Redes de ciudades y externalidades

    Directory of Open Access Journals (Sweden)

    Rafael Boix Domènech

    2004-01-01

    Full Text Available El concepto de «economías de aglomeración» explica la existencia de ventajas derivadas de la concentración de la población y la actividad. Sin embargo, no explica la existencia de economías externas espacialmente dinámicas. Las economías de red generadas en redes de ciudades corresponden a este último tipo, puesto que se generan por la interacción entre unidades urbanas, entre las que existe un vínculo de red. El objetivo de la presente investigación es avanzar en el estudio de la relación entre las redes de ciudades y la generación de economías externas. La investigación se divide en cuatro partes: en la primera se expone la relación entre las redes de ciudades y las economías externas. La segunda parte plantea un modelo para la medición conjunta de las economías de concentración y de red. La tercera parte explica los resultados de aplicar el modelo a un caso de estudio: la red de ciudades de Cataluña. Los resultados sugieren que existe una relación causal entre la organización de las unidades urbanas formando redes de ciudades y la generación de economías externas que afectan al crecimiento y desarrollo económico. Finalmente, se exponen las conclusiones y sus implicaciones en el diseño de políticas económicas.

  3. Redes sociais e conflito organizacional

    Directory of Open Access Journals (Sweden)

    Jorge Ávila de Lima

    2016-06-01

    Full Text Available As organizações são redes sociais cujos membros estabelecem entre si ligações de diversos tipos, formais e informais, positivas e negativas. O conflito entre atores é um processo comum que pode ser explicado com base num conjunto diverso de fatores. Contudo, o conflito interno às organizações tem sido pouco estudado, numa perpetiva de redes sociais. Para além disto, o conflito interorganizacional, analisado ao nível dos atores individuais, tem sido ainda menos estudado. No presente artigo, procuramos abordar o modo como as redes sociais das organizações estão associadas a perceções de conflito, quer intra-organizacional, quer interorganizacional, num contexto de proximidade física entre organizações. O estudo empírico, que envolveu duas organizações que partilhavam o mesmo espaço físico, mostra que, apesar da grande proximidade espacial entre ambas, os laços de amizade tendiam a concentrar-se no interior de cada organização e as perceções de conflito eram maiores entre as organizações do que no interior das mesmas. Os resultados são discutidos à luz das teses sobre os efeitos da propinquidade física sobre a atração interpessoal entre membros de grupos distintos

  4. Redes sociales para educomunicadores : recursos y experiencias

    OpenAIRE

    Universitat Autònoma de Barcelona. Máster en Comunicación y Educación (online)

    2013-01-01

    Las redes sociales han sido universalmente acogidas entre los usuarios de internet como una manera comprometerse en eventos, grupos sociales y temas de interés. Estos usuarios han encontrado en las redes un espacio para compartir información, socializar y, en muchos casos, construir verdaderas redes de cooperación y colaboración, un uso que puede ampliarse aún más en la medida en que madure la alfabetización mediática de sus participantes. Este informe muestra las principales redes sociales, ...

  5. Aplicación de análisis de conglomerados y redes neuronales artificiales para la clasificación y selección de candidatos a residencias médicas Cluster analysis and artificial neural networks for residency candidates classification and selection

    Directory of Open Access Journals (Sweden)

    Raúl A. Borracci

    2005-03-01

    Full Text Available Introducción: Los programas educacionales han recurrido a distintos modelos de regresión lineal múltiple, de selección asistida por computadora y más recientemente, de redes neuronales artificiales para la confección de listados preliminares de mérito entre los postulantes a la residencia. Objetivo: evaluar y rediseñar un sistema para la selección y clasificación de aspirantes a un programa de residencias universitarias por medio de la aplicación de modelos de análisis multivariante y de redes neuronales artificiales. Material y Método: El diseño consistió en un estudio retrospectivo-transversal, realizado en un hospital universitario. Se evaluó una muestra al azar de 213 aspirantes a un programa de residencias médicas universitarias teniendo en cuenta el promedio de la carrera de grado, el resultado del examen de ingreso a la residencia, los antecedentes curriculares y biográficos, el internado y el puntaje de las entrevistas. Se aplicó un análisis de conglomerados jerárquico (clúster análisis para la clasificación y selección de los candidatos en un orden de mérito en base a los puntajes estandarizados de las 5 variables. Resultados: El análisis de conglomerados jerárquico clasificó 209 aspirantes en 12 conglomerados en base al promedio estandarizado de los valores obtenidos de las 5 variables. Este análisis se usó para construir una clasificación descriptiva de los grupos y una lista final por mérito de acuerdo a la posición relativa de cada candidato por encima o debajo de los puntajes promedios. Se imitó la solución de conglomerados por medio de una red perceptrón multicapa con una sensibilidad y especificidad de 94.1 y 99.1% respectivamente. Conclusiones: El análisis de conglomerados jerárquico fue un método útil y novedoso para clasificar una muestra de aspirantes a la residencia en conglomerados de acuerdo a la posición relativa de sus puntajes estandarizados por encima o por debajo de la media

  6. Prediction of incrustation thickness in pipes used in transport of petroleum using gamma radiation and artificial neural network; Predição da espessura de incrustação em tubulações usadas no transporte de petróleo utilizando radiação gama e rede neural artificial

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Tâmara Porfíro

    2018-05-01

    This work presents a methodology for predicting concentric and eccentric scales in pipelines used in the offshore oil industry. The approximation is based on the principles of gamma densitometry and artificial neural networks. A preliminary study model was developed to define the compositions of the duct and scale. In order to do so, the influence of pipeline transmission with four different types of steel used in oil platforms was evaluated, as well as the influence of the main inorganic deposit formations. The divergence of the radioactive source was also considered in this evaluation, with collimation openings of 2 mm to 7 mm, with steps of 2.5 mm. After defining the composition of the duct and scale, a measurement geometry was defined by means of the MCNP-X code to calculate the scale thickness by means of analytical equations, independent of the fluids present in the duct (salt water, gas and oil). The representative geometry uses a duct composed of iron, with inorganic scale formed by barium sulfate (BaSO{sub 4}). Concentric scale models were simulated and the data obtained were used for training and validation of an artificial neural network, as well as eccentric scale models. The simulated detection system consisted of a narrow-beam geometry with a 2 mm collimation aperture, comprising a gamma ray source ({sup 137}Cs) and 2 x 2 “NaI (Tl) sensors suitably positioned around the duct-scale-fluid system for calculation of the scale thickness considering the transmitted beam and the scattered beam. Compton scattering was considered in cases of eccentric scale to aid in the determination and location of maximum scale thicknesses. The theoretical models were developed using the mathematical code MCNP-X and used for training, testing and validation of artificial neural networks. The proposed methodology was able to predict the concentric and eccentric scale thicknesses with satisfactory results for these two types of inorganic formations. (author)

  7. Redes neuronales de propagación inversa

    Directory of Open Access Journals (Sweden)

    Jesús Alberto Delgado Rivera

    1992-05-01

    Full Text Available Este artículo presenta la red neuronal por capas, su algoritmo de aprendizaje y una aplicación. Para lograr este propósito se inicia con la neurona natural y su modelo Entrada/Salida denominado neurona artificial.

  8. Single neuron computation

    CERN Document Server

    McKenna, Thomas M; Zornetzer, Steven F

    1992-01-01

    This book contains twenty-two original contributions that provide a comprehensive overview of computational approaches to understanding a single neuron structure. The focus on cellular-level processes is twofold. From a computational neuroscience perspective, a thorough understanding of the information processing performed by single neurons leads to an understanding of circuit- and systems-level activity. From the standpoint of artificial neural networks (ANNs), a single real neuron is as complex an operational unit as an entire ANN, and formalizing the complex computations performed by real n

  9. Posibilidades educativas de las redes sociales

    OpenAIRE

    Dans Álvarez de Sotomayor, Isabel

    2016-01-01

    [Resumen] El choque entre la realidad personal de la generación que sólo ha conocido un mundo con Internet y las redes sociales al alcance provoca cierta incertidumbre en la educación. Por un lado, se trata de hacerse con las redes sociales sin abandonar los fines educativos y, por otro, de aprovechar los medios para alcanzar metas más altas. En la primera parte se revisa la literatura sobre el tema tratando conceptos como sociedad del conocimiento, tecnología, identidad, web social, redes so...

  10. Artificial Astrocytes Improve Neural Network Performance

    Science.gov (United States)

    Porto-Pazos, Ana B.; Veiguela, Noha; Mesejo, Pablo; Navarrete, Marta; Alvarellos, Alberto; Ibáñez, Oscar; Pazos, Alejandro; Araque, Alfonso

    2011-01-01

    Compelling evidence indicates the existence of bidirectional communication between astrocytes and neurons. Astrocytes, a type of glial cells classically considered to be passive supportive cells, have been recently demonstrated to be actively involved in the processing and regulation of synaptic information, suggesting that brain function arises from the activity of neuron-glia networks. However, the actual impact of astrocytes in neural network function is largely unknown and its application in artificial intelligence remains untested. We have investigated the consequences of including artificial astrocytes, which present the biologically defined properties involved in astrocyte-neuron communication, on artificial neural network performance. Using connectionist systems and evolutionary algorithms, we have compared the performance of artificial neural networks (NN) and artificial neuron-glia networks (NGN) to solve classification problems. We show that the degree of success of NGN is superior to NN. Analysis of performances of NN with different number of neurons or different architectures indicate that the effects of NGN cannot be accounted for an increased number of network elements, but rather they are specifically due to astrocytes. Furthermore, the relative efficacy of NGN vs. NN increases as the complexity of the network increases. These results indicate that artificial astrocytes improve neural network performance, and established the concept of Artificial Neuron-Glia Networks, which represents a novel concept in Artificial Intelligence with implications in computational science as well as in the understanding of brain function. PMID:21526157

  11. Artificial astrocytes improve neural network performance.

    Directory of Open Access Journals (Sweden)

    Ana B Porto-Pazos

    Full Text Available Compelling evidence indicates the existence of bidirectional communication between astrocytes and neurons. Astrocytes, a type of glial cells classically considered to be passive supportive cells, have been recently demonstrated to be actively involved in the processing and regulation of synaptic information, suggesting that brain function arises from the activity of neuron-glia networks. However, the actual impact of astrocytes in neural network function is largely unknown and its application in artificial intelligence remains untested. We have investigated the consequences of including artificial astrocytes, which present the biologically defined properties involved in astrocyte-neuron communication, on artificial neural network performance. Using connectionist systems and evolutionary algorithms, we have compared the performance of artificial neural networks (NN and artificial neuron-glia networks (NGN to solve classification problems. We show that the degree of success of NGN is superior to NN. Analysis of performances of NN with different number of neurons or different architectures indicate that the effects of NGN cannot be accounted for an increased number of network elements, but rather they are specifically due to astrocytes. Furthermore, the relative efficacy of NGN vs. NN increases as the complexity of the network increases. These results indicate that artificial astrocytes improve neural network performance, and established the concept of Artificial Neuron-Glia Networks, which represents a novel concept in Artificial Intelligence with implications in computational science as well as in the understanding of brain function.

  12. Artificial astrocytes improve neural network performance.

    Science.gov (United States)

    Porto-Pazos, Ana B; Veiguela, Noha; Mesejo, Pablo; Navarrete, Marta; Alvarellos, Alberto; Ibáñez, Oscar; Pazos, Alejandro; Araque, Alfonso

    2011-04-19

    Compelling evidence indicates the existence of bidirectional communication between astrocytes and neurons. Astrocytes, a type of glial cells classically considered to be passive supportive cells, have been recently demonstrated to be actively involved in the processing and regulation of synaptic information, suggesting that brain function arises from the activity of neuron-glia networks. However, the actual impact of astrocytes in neural network function is largely unknown and its application in artificial intelligence remains untested. We have investigated the consequences of including artificial astrocytes, which present the biologically defined properties involved in astrocyte-neuron communication, on artificial neural network performance. Using connectionist systems and evolutionary algorithms, we have compared the performance of artificial neural networks (NN) and artificial neuron-glia networks (NGN) to solve classification problems. We show that the degree of success of NGN is superior to NN. Analysis of performances of NN with different number of neurons or different architectures indicate that the effects of NGN cannot be accounted for an increased number of network elements, but rather they are specifically due to astrocytes. Furthermore, the relative efficacy of NGN vs. NN increases as the complexity of the network increases. These results indicate that artificial astrocytes improve neural network performance, and established the concept of Artificial Neuron-Glia Networks, which represents a novel concept in Artificial Intelligence with implications in computational science as well as in the understanding of brain function.

  13. Simulation of lung motions using an artificial neural network; Utilisation d'un reseau de neurones artificiels pour la simulation des mouvements pulmonaires

    Energy Technology Data Exchange (ETDEWEB)

    Laurent, R.; Henriet, J.; Sauget, M.; Gschwind, R.; Makovicka, L. [IRMA/ENISYS/FEMTO-ST, UMR 6174 CNRS, pole universitaire des Portes du Jura, BP 71427, 25211 Montbeliard cedex (France); Salomon, M. [AND/LIFC, universite de Franche-Comte, BP 527, rue Engel-Gros, 90016 Belfort cedex (France); Nguyen, F. [Service de radiotherapie, CHU Jean-Minjoz, 3, boulevard Fleming, 25030 Besancon cedex (France)

    2011-04-15

    Purpose. A way to improve the accuracy of lung radiotherapy for a patient is to get a better understanding of its lung motion. Indeed, thanks to this knowledge it becomes possible to follow the displacements of the clinical target volume (CTV) induced by the lung breathing. This paper presents a feasibility study of an original method to simulate the positions of points in patient's lung at all breathing phases. Patients and methods. This method, based on an artificial neural network, allowed learning the lung motion on real cases and then to simulate it for new patients for which only the beginning and the end breathing data are known. The neural network learning set is made up of more than 600 points. These points, shared out on three patients and gathered on a specific lung area, were plotted by a MD. Results. - The first results are promising: an average accuracy of 1 mm is obtained for a spatial resolution of 1 x 1 x 2.5 mm{sup 3}. Conclusion. We have demonstrated that it is possible to simulate lung motion with accuracy using an artificial neural network. As future work we plan to improve the accuracy of our method with the addition of new patient data and a coverage of the whole lungs. (authors)

  14. Redes Atm de Alto Desempenho

    Directory of Open Access Journals (Sweden)

    Flávia Oliveira Santos de Sá Lisboa

    2015-12-01

    Full Text Available A tendência atual de integração de serviços de dados, voz e vídeo, estimulada pelo pleno sucesso da Internet, aumentou a demanda por maior banda e melhor desempenho nas redes de comunicação de dados. Neste contexto, a tecnologia ATM (Asynchronous Transfer Mode vem sendo utilizada na implementação de backbone de LANs e WANs, justamente por oferecer a possibilidade de integração de serviços com qualidade, alta escalabilidade e altas taxas de transferência em banda larga. Neste artigo serão abordados os principais conceitos relacionados à tecnologia ATM, suas vantagens e desvantagens em face de outras tecnologias (como Fast e Gigabit Ethernet, além de casos de sua utilização em empresas e instituições de ensino.

  15. The principles of artificial neural network information processing

    International Nuclear Information System (INIS)

    Dai, Ru-Wei

    1993-01-01

    In this article, the basic structure of an artificial neuron is first introduced. In addition, principles of artificial neural network as well as several important artificial neural models such as perception, back propagation model, Hopfield net, and ART model are briefly discussed and analyzed. Finally the application of artificial neural network for Chinese character recognition is also given. (author)

  16. The principles of artificial neural network information processing

    International Nuclear Information System (INIS)

    Dai, Ru-Wei

    1993-01-01

    In this article, the basic structure of an artificial neuron is first introduced. In addition, principles of artificial neural network as well as several important artificial neural models such as Perceptron, Back propagation model, Hopfield net, and ART model are briefly discussed and analyzed. Finally, the application of artificial neural network for Chinese Character Recognition is also given. (author)

  17. Las redes sociales presentes en las bibliotecas

    Directory of Open Access Journals (Sweden)

    Magda Cecilia Sandí S.

    2012-01-01

    Full Text Available El presente artículo pretende evidenciar la importancia del uso de las redes sociales en las bibliotecas como una herramienta y un canal de comunicación entre el bibliotecólogo y la comunidad de usuarios. Las redes sociales son una nueva forma de comunicarnos entre las y los usuarios del Internet, su uso es irrestricto y cada vez aumenta la comunidad de usuarios de estas herramientas en la red.

  18. Las redes sociales presentes en las bibliotecas

    Directory of Open Access Journals (Sweden)

    Magda Cecilia Sandí Sandí

    2012-07-01

    Full Text Available El presente artículo pretende evidenciar la importancia del uso de las redes sociales en las bibliotecas como una herramienta y un canal de comunicación entre el bibliotecólogo y la comunidad de usuarios. Las redes sociales son una nueva forma de comunicarnos entre las y los usuarios del Internet, su uso es irrestricto y cada vez aumenta la comunidad de usuarios de estas herramientas en la red.

  19. El sujeto posmoderno en las redes sociales

    OpenAIRE

    Elizondo, Mauricio; Picot, Carla

    2011-01-01

    Nuestro recorrido comienza con las características contemporáneas de los conceptos de vida pública y vida privada, y bajo el marco de las redes sociales, cómo estos ámbitos se reflejan en las subjetividades de los usuarios. En suma, intentaremos desarrollar qué son y cómo son utilizadas estas redes sociales en la actualidad por este sujeto posmoderno.

  20. Las redes sociales presentes en las bibliotecas

    OpenAIRE

    Magda Cecilia Sandí S.

    2012-01-01

    El presente artículo pretende evidenciar la importancia del uso de las redes sociales en las bibliotecas como una herramienta y un canal de comunicación entre el bibliotecólogo y la comunidad de usuarios. Las redes sociales son una nueva forma de comunicarnos entre las y los usuarios del Internet, su uso es irrestricto y cada vez aumenta la comunidad de usuarios de estas herramientas en la red.

  1. Artificial intelligence

    CERN Document Server

    Hunt, Earl B

    1975-01-01

    Artificial Intelligence provides information pertinent to the fundamental aspects of artificial intelligence. This book presents the basic mathematical and computational approaches to problems in the artificial intelligence field.Organized into four parts encompassing 16 chapters, this book begins with an overview of the various fields of artificial intelligence. This text then attempts to connect artificial intelligence problems to some of the notions of computability and abstract computing devices. Other chapters consider the general notion of computability, with focus on the interaction bet

  2. Aplicação de redes neurais para avaliação do teor de carne mecanicamente separada em salsicha de frango Application of neural network for evaluation of the amount of mechanically deboned poultry meat in sausage

    Directory of Open Access Journals (Sweden)

    Erlandsson Anthony de Sousa

    2003-12-01

    Full Text Available A carne mecanicamente separada (CMS de frango é uma matéria-prima cárnea produzida através de equipamentos próprios do tipo desossadores mecânicos, utilizando partes de frango de baixo valor comercial como o dorso e o pescoço. Para determinação do teor de CMS utilizada na composição de produtos cárneos comerciais construímos uma rede neural artificial do tipo Backpropagation (BP. O objetivo deste trabalho foi treinar, testar e aplicar uma rede do tipo BP, com três camadas de neurônios, para previsão do teor de CMS a partir do teor de minerais de salsichas formuladas com diferentes teores de carne de frango mecanicamente separada. Utilizamos a composição mineral de 29 amostras de salsicha contendo diferentes teores de CMS e 22 amostras de produtos cárneos comerciais. A topologia da rede foi 5-5-1. O erro quadrático médio no conjunto de treinamento foi de 2,4% e na fase de teste foi de apenas 3,8%. No entanto, a aplicação da rede às amostras comerciais foi inadequada devido à diferença de ingredientes das salsichas usadas no treinamento e os ingredientes das amostras comerciais. A rede neural construída para determinação do teor de carne mecanicamente separada mostrou-se eficiente durante a fase de treinamento e teste da rede.Mechanically Deboned Poultry Meat (MDPM is constituted of the neck and back from chicken carcasses that are extracted in machine. An artificial neural network of the Back-Propagation type was built to determine the amount of MDPM in the composition of commercial foods. The objective of this work was to train, evaluate and apply a network of the Back-Propagation type, with three layers of neurons, in predicting the amount of MDPM in relation to the amount of minerals in the sausage. We used the mineral composition of 29 product samples that contained different amounts of MDPM and 23 commercial samples. The topology of the network was a 5-5-1. The average quadratic error in the training group was of

  3. Reconstruction of the neutron spectrum using an artificial neural network in CPU and GPU; Reconstruccion del espectro de neutrones usando una red neuronal artificial (RNA) en CPU y GPU

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez D, V. M.; Moreno M, A.; Ortiz L, M. A. [Universidad de Cordoba, 14002 Cordoba (Spain); Vega C, H. R.; Alonso M, O. E., E-mail: vic.mc68010@gmail.com [Universidad Autonoma de Zacatecas, 98000 Zacatecas, Zac. (Mexico)

    2016-10-15

    The increase in computing power in personal computers has been increasing, computers now have several processors in the CPU and in addition multiple CUDA cores in the graphics processing unit (GPU); both systems can be used individually or combined to perform scientific computation without resorting to processor or supercomputing arrangements. The Bonner sphere spectrometer is the most commonly used multi-element system for neutron detection purposes and its associated spectrum. Each sphere-detector combination gives a particular response that depends on the energy of the neutrons, and the total set of these responses is known like the responses matrix Rφ(E). Thus, the counting rates obtained with each sphere and the neutron spectrum is related to the Fredholm equation in its discrete version. For the reconstruction of the spectrum has a system of poorly conditioned equations with an infinite number of solutions and to find the appropriate solution, it has been proposed the use of artificial intelligence through neural networks with different platforms CPU and GPU. (Author)

  4. Comparison between artificial neural networks and maximum likelihood classification in digital soil mapping Comparação entre redes neurais artificiais e classificação por máxima verossimilhança no mapeamento digital de solos

    Directory of Open Access Journals (Sweden)

    César da Silva Chagas

    2013-04-01

    Full Text Available Soil surveys are the main source of spatial information on soils and have a range of different applications, mainly in agriculture. The continuity of this activity has however been severely compromised, mainly due to a lack of governmental funding. The purpose of this study was to evaluate the feasibility of two different classifiers (artificial neural networks and a maximum likelihood algorithm in the prediction of soil classes in the northwest of the state of Rio de Janeiro. Terrain attributes such as elevation, slope, aspect, plan curvature and compound topographic index (CTI and indices of clay minerals, iron oxide and Normalized Difference Vegetation Index (NDVI, derived from Landsat 7 ETM+ sensor imagery, were used as discriminating variables. The two classifiers were trained and validated for each soil class using 300 and 150 samples respectively, representing the characteristics of these classes in terms of the discriminating variables. According to the statistical tests, the accuracy of the classifier based on artificial neural networks (ANNs was greater than of the classic Maximum Likelihood Classifier (MLC. Comparing the results with 126 points of reference showed that the resulting ANN map (73.81 % was superior to the MLC map (57.94 %. The main errors when using the two classifiers were caused by: a the geological heterogeneity of the area coupled with problems related to the geological map; b the depth of lithic contact and/or rock exposure, and c problems with the environmental correlation model used due to the polygenetic nature of the soils. This study confirms that the use of terrain attributes together with remote sensing data by an ANN approach can be a tool to facilitate soil mapping in Brazil, primarily due to the availability of low-cost remote sensing data and the ease by which terrain attributes can be obtained.O levantamento de solos é a principal fonte de informação espacial sobre solos para diferentes usos

  5. El impacto de la estructura de las redes sociales sobre el acceso de los individuos al mercado laboral

    Directory of Open Access Journals (Sweden)

    García-Valdecasas, José Ignacio

    2014-08-01

    Full Text Available This work attempts to analyse the effect of social networks structure on the access to the labour market for individuals through the diffusion of information which takes place in such networks (an aspect of social capital. For that purpose, it combines agent-based modelling and social network analysis in order to carry out virtual experiments with artificial networks. The results show that not only the type of structure (small world, free scale networks, random networks and regular networks, but also certain structural properties such as the density of network, the index of globalization in links or the degree of inequality in the distribution of links affect deeply on the opportunities of agents in order to achieve employment.Este trabajo pretende analizar el efecto de la estructura de las redes sociales sobre el acceso de los individuos al mercado laboral a través de la difusión de la información que tiene lugar en dichas redes (un aspecto del capital social. Para realizar tal análisis, se ha llevado a cabo una serie de experimentos virtuales con redes artificiales, utilizando para ello la simulación basada en agentes y el análisis de redes sociales. Los resultados muestran que no solo el tipo de estructura (mundos pequeños, redes de libre escala, redes aleatorias y redes regulares, sino también ciertas propiedades estructurales como la densidad de red, el índice de globalización de vínculos o el grado de desigualdad en la distribución de vínculos influyen considerablemente sobre las oportunidades de los agentes de conseguir empleo.

  6. Desenvolvimento de uma aplicação para reconhecer significado de palavras homônimas utilizando redes neurais artificiais

    Directory of Open Access Journals (Sweden)

    Eduardo Gabriel Côrtes

    2016-07-01

    Full Text Available Este trabalho propõe desenvolver uma aplicação para auxiliar no entendimento do significado de palavras ambíguas da língua portuguesa, que dependem necessariamente do contexto para serem identificadas. A aplicação foi implementada na linguagem de programação JAVA, utilizando a IDE NetBeans, juntamente com a ferramenta ADReNA, que permitiu modelar e treinar a rede neural artificial backpropagation. Foram desenvolvidas duas versões da aplicação, que se diferenciam pela forma que representam a camada de entrada da rede neural artificial. Testes realizados mostraram que a forma que a rede neural é representada gera influência em seus resultados. Após a realização dos testes, a aplicação se mostrou promissora no reconhecimento de significados de palavras homônimas.

  7. Inteligência artificial aplicada à Zootecnia Artificial intelligence in Animal Science

    Directory of Open Access Journals (Sweden)

    Ernane José Xavier Costa

    2009-07-01

    Full Text Available Os sistemas biológicos são surpreendentemente flexíveis pra processar informação proveniente do mundo real. Alguns organismos biológicos possuem uma unidade central de processamento denominada de cérebro. O cérebro humano consiste de 10(11 neurônios e realiza processamento inteligente de forma exata e subjetiva. A Inteligência Artificial (IA tenta trazer para o mundo da computação digital a heurística dos sistemas biológicos de várias maneiras, mas, ainda resta muito para que isso seja concretizado. No entanto, algumas técnicas como Redes neurais artificiais e lógica fuzzy tem mostrado efetivas para resolver problemas complexos usando a heurística dos sistemas biológicos. Recentemente o numero de aplicação dos métodos da IA em sistemas zootécnicos tem aumentado significativamente. O objetivo deste artigo é explicar os princípios básicos da resolução de problemas usando heurística e demonstrar como a IA pode ser aplicada para construir um sistema especialista para resolver problemas na área de zootecnia.Biological systems are surprising flexible in processing information in the real world. Some biological organisms have a central unit processing named brain. The human's brain, consisting of 10(11 neurons, realizes intelligent information processing based on exact and commonsense reasoning. Artificial intelligence (AI has been trying to implement biological intelligence in computers in various ways, but is still far from real one. Therefore, there are approaches like Symbolic AI, Artificial Neural Network and Fuzzy system that partially successful in implementing heuristic from biological intelligence. Many recent applications of these approaches show an increased interest in animal science research. The main goal of this article is to explain the principles of heuristic problem-solving approach and to demonstrate how they can be applied to building knowledge-based systems for animal science problem solving.

  8. Artificial Intelligence and brain.

    Science.gov (United States)

    Shapshak, Paul

    2018-01-01

    From the start, Kurt Godel observed that computer and brain paradigms were considered on a par by researchers and that researchers had misunderstood his theorems. He hailed with displeasure that the brain transcends computers. In this brief article, we point out that Artificial Intelligence (AI) comprises multitudes of human-made methodologies, systems, and languages, and implemented with computer technology. These advances enhance development in the electron and quantum realms. In the biological realm, animal neurons function, also utilizing electron flow, and are products of evolution. Mirror neurons are an important paradigm in neuroscience research. Moreover, the paradigm shift proposed here - 'hall of mirror neurons' - is a potentially further productive research tactic. These concepts further expand AI and brain research.

  9. Neural Network Molecule: a Solution of the Inverse Biometry Problem through Software Support of Quantum Superposition on Outputs of the Network of Artificial Neurons

    Directory of Open Access Journals (Sweden)

    Vladimir I. Volchikhin

    2017-12-01

    Full Text Available Introduction: The aim of the study is to accelerate the solution of neural network biometrics inverse problem on an ordinary desktop computer. Materials and Methods: To speed up the calculations, the artificial neural network is introduced into the dynamic mode of “jittering” of the states of all 256 output bits. At the same time, too many output states of the neural network are logarithmically folded by transitioning to the Hamming distance space between the code of the image “Own” and the codes of the images “Alien”. From the database of images of “Alien” 2.5 % of the most similar images are selected. In the next generation, 97.5 % of the discarded images are restored with GOST R 52633.2-2010 procedures by crossing parent images and obtaining descendant images from them. Results: Over a period of about 10 minutes, 60 generations of directed search for the solution of the inverse problem can be realized that allows inversing matrices of neural network functionals of dimension 416 inputs to 256 outputs with restoration of up to 97 % information on unknown biometric parameters of the image “Own”. Discussion and Conclusions: Supporting for 10 minutes of computer time the 256 qubit quantum superposition allows on a conventional computer to bypass the actual infinity of analyzed states in 5050 (50 to 50 times more than the same computer could process realizing the usual calculations. The increase in the length of the supported quantum superposition by 40 qubits is equivalent to increasing the processor clock speed by about a billion times. It is for this reason that it is more profitable to increase the number of quantum superpositions supported by the software emulator in comparison with the creation of a more powerful processor.

  10. Análise de Rede Social

    Directory of Open Access Journals (Sweden)

    Carlos Leonardo Kelmer Mathias

    2014-06-01

    Full Text Available http://dx.doi.org/10.5007/1807-1384.2014v11n1p131 Em linhas gerais, o artigo tem por escopo empreender um debate historiográfico acerca da metodologia de análise de rede social. Mais do que responder a perguntas utilizando tal metodologia, o artigo busca introduzir o historiador à bibliografia fundadora das discussões sobre a análise de rede social. Comumente empregada por sociólogos em estudos atrelados à sociometria desde a publicação do célebre artigo de John Barnes em 1954, a análise de rede social é uma metodologia pouco difundida entre os historiadores brasileiros. Nesse sentido, o texto se propõe realizar um breve debate entre as principais linhas interpretativas da análise de rede social visando introduzir o historiador assim na metodologia em si, como na bibliografia que serviu de base das discussões atinente ao tema. Para tanto, o texto inicia com uma introdução acerca da análise de rede social para, em seguida, empreender uma discussão mais precisa sobre o tema. Por fim, o artigo esboça algumas das principais críticas sofridas pela metodologia em questão.

  11. Artificial Intelligence.

    Science.gov (United States)

    Information Technology Quarterly, 1985

    1985-01-01

    This issue of "Information Technology Quarterly" is devoted to the theme of "Artificial Intelligence." It contains two major articles: (1) Artificial Intelligence and Law" (D. Peter O'Neill and George D. Wood); (2) "Artificial Intelligence: A Long and Winding Road" (John J. Simon, Jr.). In addition, it contains two sidebars: (1) "Calculating and…

  12. CARACTERIZACIÓN DE CAFÉ CEREZA EMPLEANDO TÉCNICAS DE VISIÓN ARTIFICIAL AN ARTIFICIAL VISION SYSTEM FOR CLASSIFICATION OF COFFEE BEANS

    Directory of Open Access Journals (Sweden)

    Zulma Liliana Sandoval Niño

    2007-12-01

    Full Text Available Se desarrolló un sistema de visión artificial para la clasificación de frutos de café en once categorías dependiendo de su estado de madurez. Para la descripción de la forma, el color y la textura de cada fruto de café se extrajeron 208 características. La reducción del conjunto de características de 208 a 9 se hizo con base en los resultados de dos métodos de selección de características, uno univariado y otro multivariado. Las características seleccionadas corresponden a 4 características de textura, 3 de color y 2 de forma. Este conjunto final de características se evaluó en dos técnicas de clasificación: Bayesiano y redes neuronales. Con el clasificador Bayesiano se obtuvo un error de clasificación del 5,43% y requirió un tiempo de clasificación de 5,5 ms, mientras que usando redes neuronales el error de clasificación fue de 7,46%, pero disminuyó el tiempo de clasificación a 0,8 ms.An artificial vision system for classification of coffee beans, in eleven categories, according to its state of maturity was developed. The description of the coffee beans was done by using 208 characteristics (form, color and texture characteristics. The reduction of the set of characteristics from 208 to 9 was done by using two methods of characteristic selection. The final set of characteristics is composed by 4 texture characteristics, 3 color characteristics and 2 shape characteristics. This final set was evaluated in two classifiers: The Bayesian and a neuronal networks classifier. The classification error obtained by the Bayesian classifier was 5,43%, it required 5,5 ms for the classification process, while the error obtained by neuronal networks classifier was 7,46% and the classification time decreased to 0,8 ms.

  13. Evaluación asimétrica de una red neuronal: aplicación al caso de la inflación en Colombia

    Directory of Open Access Journals (Sweden)

    Maria Clara Aristizábal

    2006-12-01

    Full Text Available El objetivo de este trabajo es explorar la relación no lineal entre el dinero y la inflación en Colombia a través de una red neuronal artificial, utilizando información mensual de la variación del Índice de Precios al Consumidor y del agregado monetario M3, desde enero de 1982 hasta febrero de 2005. Las redes neuronales artificiales aparecen como una excelente alternativa para las autoridades monetarias de contar con los mejores modelos para pronosticar la inflación y guiar sus decisiones de política. El presente artículo incorpora algunas innovaciones en la modelación del dinero e inflación que permiten generar pronósticos más confiables, debido a que el modelo se aproxima con mayor exactitud a la realidad.

  14. Seguridad en redes inalámbricas

    OpenAIRE

    Aguirre Briones, Geannina Jackeline; Sanclemente Ordoñez, Angela Isabel; Ureta Arreaga, Laura Alexandra; Espinal Santana, Albert

    2009-01-01

    El constante avance tecnológico nos exige mejorar ciertas actividades e implementar nuevas tecnologías, como es la implementación de las redes inalambricas. Por ésta razón, nosotras hemos realizado un profundo estudio sobre los niveles de seguridad que se deben considerar en la implementación de las redes inalámbricas, los cual le permitirá a una empresar garantizar la seguridad de la información que por ella transita. Nuestro objetivo es dar a conocer los diferentes tipos de ataques info...

  15. Estudio sobre redes sociales y estudiantes

    OpenAIRE

    Toledo Morales, Purificación; Sánchez García, José Manuel

    2012-01-01

    En este estudio pretendemos analizar cómo una muestra de 150 estudiantes utiliza las redes sociales, y explorar el impacto de estas en el rendimiento académico de los mismos. Los datos recogidos de la aplicación y análisis de una escala de opinión revelaron que mas de la mitad de los estudiantes encuestados utilizan internet con una finalidad puramente recreativa, y las redes sociales para estar en contacto con los amigos. La mayoría de los encuestados rechazan las solicitudes de amistad de d...

  16. Las redes sociales y su modelado matemático

    OpenAIRE

    Ortega Guerrero, Juan Carlos

    2017-01-01

    Las tecnologías de la información y comunicación (TIC) han venido a cambiar el potencial de las redes sociales. Su diversidad, alcance y características resultan impactantes y su análisis matemático es importante para comprenderlas. En este capítulo se revisan los conceptos básicos de las redes, veremos cómo se generan las redes complejas y sus características principales; en especial se analizan las redes de mundo pequeño y su uso para modelar las redes sociales, finalmente se enuncian algun...

  17. Impactos dos nomes nas propriedades de redes sociais: um estudo em rede de coautoria sobre sustentabilidade

    Directory of Open Access Journals (Sweden)

    Rafael Garcia Barbastefano

    Full Text Available A identificação correta dos autores é fator crítico em estudos de Análise de Redes Sociais (ARS que envolvem redes de coautoria. O objetivo do trabalho é apresentar as diferenças de propriedades entre três redes de coautoria geradas com formas distintas de considerar o nome dos autores. Foi adotado o método bibliométrico. As redes foram construídas com base em 28.916 artigos sobre sustentabilidade, indexados no ISI/Web of Science, fazendo uso do software Pajek. Na análise, foram comparadas as seguintes propriedades: densidade, grau médio, componente gigante, distribuição dos graus, distância média, diâmetro da rede e coeficiente de clusterização de Watts-Strogatz. Os resultados indicaram grandes diferenças entre as redes, sugerindo que estudos de coautoria, fazendo uso de ARS, podem ter resultados comprometidos, caso não haja o tratamento adequado dos nomes dos autores. Diante do crescimento das aplicações de ARS, faz-se necessário o desenvolvimento de estudos e ferramentas voltados para mitigar a ocorrência desses erros.

  18. Redes neuronales en espectrometría y dosimetría de neutrones

    OpenAIRE

    Torre López, Jesús Alberto de la

    2017-01-01

    Este Trabajo de Fin de Grado tiene como objetivo fundamental la realización de experimentos y simulaciones que ayuden a la comprensión acerca de una de las herramientas de predicción de valores más potentes de la inteligencia artificial como son las Redes Neuronales Artificiales. Su aplicación en este trabajo será muy concreta, en el campo de la espectrometría y dosimetría de neutrones, sin embargo, sus posibles aplicaciones abarcan un campo mucho más amplio, lo cual hace de ellas una herr...

  19. Integración de inteligencia en la MIB del Modelo OSI para la gestión de redes de telecomunicaciones

    OpenAIRE

    León de Mora, Carlos; López, Alejandro; Martín Montes, Antonio

    2012-01-01

    La Gestión de red se define como el conjunto de actividades dedicadas al control y vigilancia de los recursos existentes en las redes de telecomunicaciones. En los complejos sistemas actuales, es necesario realizar una gestión de la red asistida por un software avanzado. La Inteligencia Artificial se incorpora a la gestión de las redes, con el fin de facilitar labores de administración y control de toda la información que proviene de los recursos gestionados, dando origen a la Ges...

  20. Sistema de seguridad en redes locales utilizando sistemas multiagentes distribuidos. Net-Mass

    Directory of Open Access Journals (Sweden)

    Daniel Horfan Álvarez

    2005-01-01

    Full Text Available La seguridad en las redes de datos es uno de los elementos neurálgicos dentro de una organización, ya que requiere de diferentes estrategias de protección para salvaguardar puntos vulnerables, y de la coordinación y distribución de esfuerzos para cercar todas las posibles formas de ataques informáticos. En este artículo se propone un sistema multiagente distribuido como herramienta de protección para redes con diferentes sistemas operativos y susceptibilidad de diversos ataques.El sistema propuesto está conformado por un grupo de agentes autónomos heterogéneos con características particulares en cuanto a sus estrategias de detección de intrusos y protección de los sistemas primordiales de la red, se tiene planeado que estos agentes basen sus decisiones en la aplicación de diferentes técnicas de inteligencia artificial como heurística de sistemas expertos, algoritmos evolutivos y redes neuronales.

  1. Artificial Consciousness or Artificial Intelligence

    OpenAIRE

    Spanache Florin

    2017-01-01

    Artificial intelligence is a tool designed by people for the gratification of their own creative ego, so we can not confuse conscience with intelligence and not even intelligence in its human representation with conscience. They are all different concepts and they have different uses. Philosophically, there are differences between autonomous people and automatic artificial intelligence. This is the difference between intelligence and artificial intelligence, autonomous versus a...

  2. [Artificial organs].

    Science.gov (United States)

    Raguin, Thibaut; Dupret-Bories, Agnès; Debry, Christian

    2017-01-01

    Research has been fighting against organ failure and shortage of donations by supplying artificial organs for many years. With the raise of new technologies, tissue engineering and regenerative medicine, many organs can benefit of an artificial equivalent: thanks to retinal implants some blind people can visualize stimuli, an artificial heart can be proposed in case of cardiac failure while awaiting for a heart transplant, artificial larynx enables laryngectomy patients to an almost normal life, while the diabetic can get a glycemic self-regulation controlled by smartphones with an artificial device. Dialysis devices become portable, as well as the oxygenation systems for terminal respiratory failure. Bright prospects are being explored or might emerge in a near future. However, the retrospective assessment of putative side effects is not yet sufficient. Finally, the cost of these new devices is significant even if the advent of three dimensional printers may reduce it. © 2017 médecine/sciences – Inserm.

  3. Parvalbumin+ Neurons and Npas1+ Neurons Are Distinct Neuron Classes in the Mouse External Globus Pallidus.

    Science.gov (United States)

    Hernández, Vivian M; Hegeman, Daniel J; Cui, Qiaoling; Kelver, Daniel A; Fiske, Michael P; Glajch, Kelly E; Pitt, Jason E; Huang, Tina Y; Justice, Nicholas J; Chan, C Savio

    2015-08-26

    Compelling evidence suggests that pathological activity of the external globus pallidus (GPe), a nucleus in the basal ganglia, contributes to the motor symptoms of a variety of movement disorders such as Parkinson's disease. Recent studies have challenged the idea that the GPe comprises a single, homogenous population of neurons that serves as a simple relay in the indirect pathway. However, we still lack a full understanding of the diversity of the neurons that make up the GPe. Specifically, a more precise classification scheme is needed to better describe the fundamental biology and function of different GPe neuron classes. To this end, we generated a novel multicistronic BAC (bacterial artificial chromosome) transgenic mouse line under the regulatory elements of the Npas1 gene. Using a combinatorial transgenic and immunohistochemical approach, we discovered that parvalbumin-expressing neurons and Npas1-expressing neurons in the GPe represent two nonoverlapping cell classes, amounting to 55% and 27% of the total GPe neuron population, respectively. These two genetically identified cell classes projected primarily to the subthalamic nucleus and to the striatum, respectively. Additionally, parvalbumin-expressing neurons and Npas1-expressing neurons were distinct in their autonomous and driven firing characteristics, their expression of intrinsic ion conductances, and their responsiveness to chronic 6-hydroxydopamine lesion. In summary, our data argue that parvalbumin-expressing neurons and Npas1-expressing neurons are two distinct functional classes of GPe neurons. This work revises our understanding of the GPe, and provides the foundation for future studies of its function and dysfunction. Until recently, the heterogeneity of the constituent neurons within the external globus pallidus (GPe) was not fully appreciated. We addressed this knowledge gap by discovering two principal GPe neuron classes, which were identified by their nonoverlapping expression of the

  4. Parvalbumin+ Neurons and Npas1+ Neurons Are Distinct Neuron Classes in the Mouse External Globus Pallidus

    Science.gov (United States)

    Hernández, Vivian M.; Hegeman, Daniel J.; Cui, Qiaoling; Kelver, Daniel A.; Fiske, Michael P.; Glajch, Kelly E.; Pitt, Jason E.; Huang, Tina Y.; Justice, Nicholas J.

    2015-01-01

    Compelling evidence suggests that pathological activity of the external globus pallidus (GPe), a nucleus in the basal ganglia, contributes to the motor symptoms of a variety of movement disorders such as Parkinson's disease. Recent studies have challenged the idea that the GPe comprises a single, homogenous population of neurons that serves as a simple relay in the indirect pathway. However, we still lack a full understanding of the diversity of the neurons that make up the GPe. Specifically, a more precise classification scheme is needed to better describe the fundamental biology and function of different GPe neuron classes. To this end, we generated a novel multicistronic BAC (bacterial artificial chromosome) transgenic mouse line under the regulatory elements of the Npas1 gene. Using a combinatorial transgenic and immunohistochemical approach, we discovered that parvalbumin-expressing neurons and Npas1-expressing neurons in the GPe represent two nonoverlapping cell classes, amounting to 55% and 27% of the total GPe neuron population, respectively. These two genetically identified cell classes projected primarily to the subthalamic nucleus and to the striatum, respectively. Additionally, parvalbumin-expressing neurons and Npas1-expressing neurons were distinct in their autonomous and driven firing characteristics, their expression of intrinsic ion conductances, and their responsiveness to chronic 6-hydroxydopamine lesion. In summary, our data argue that parvalbumin-expressing neurons and Npas1-expressing neurons are two distinct functional classes of GPe neurons. This work revises our understanding of the GPe, and provides the foundation for future studies of its function and dysfunction. SIGNIFICANCE STATEMENT Until recently, the heterogeneity of the constituent neurons within the external globus pallidus (GPe) was not fully appreciated. We addressed this knowledge gap by discovering two principal GPe neuron classes, which were identified by their nonoverlapping

  5. Arquitectura de Seguridad para las redes de Telecomunicaciones

    Directory of Open Access Journals (Sweden)

    Caridad Anías Calderón

    2011-01-01

    Full Text Available Normal 0 21 false false false ES X-NONE X-NONE MicrosoftInternetExplorer4 La industria de las telecomunicaciones necesita disponer de normas de trabajo para la gestión de seguridad, acordes a los requerimientos y particularidades de las redes modernas. En este artículo se propone una arquitectura de seguridad general, sencilla y flexible que constituye una herramienta para la gestión de seguridad en las redes de telecomunicaciones. Se presentan sus principales componentes, características y aportes, y se discuten los casos de su aplicación en las redes de datos tradicionales, y en las Redes de Próxima Generación (NGN, por sus siglas en inglés, principal tendencia de esta industria. Palabras claves: arquitectura de seguridad, gestión de redes, gestión de seguridad, NGN, redes, seguridad, telecomunicaciones.

  6. Artificial intelligence

    CERN Document Server

    Ennals, J R

    1987-01-01

    Artificial Intelligence: State of the Art Report is a two-part report consisting of the invited papers and the analysis. The editor first gives an introduction to the invited papers before presenting each paper and the analysis, and then concludes with the list of references related to the study. The invited papers explore the various aspects of artificial intelligence. The analysis part assesses the major advances in artificial intelligence and provides a balanced analysis of the state of the art in this field. The Bibliography compiles the most important published material on the subject of

  7. Artificial Reefs

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — An artificial reef is a human-made underwater structure, typically built to promote marine life in areas with a generally featureless bottom, control erosion, block...

  8. CACTI: MONITORAMENTO PREDITIVO DE ATIVOS DE REDE

    Directory of Open Access Journals (Sweden)

    Gian Sávio Morais

    2016-11-01

    Full Text Available Este trabalho trata da adoção da ferramenta de monitoramento de ativos de rede Cacti na rede de computadores de uma empresa localizada em Santa Rita do Sapucaí – MG, onde foram detectados problemas de interrupção em serviços classificados como críticos para o contínuo andamento das demais atividades da empresa. O objetivo da ferramenta é monitorar preditivamente esses dispositivos em missão crítica a fim de reduzir as possíveis falhas que possam vir a ocorrer, facilitando a detecção de mal funcionamento e viabilizando ações preventivas e corretivas. O Cacti coleta, armazena e apresenta informações sobre o funcionamento dos dispositivos através de gráficos, se comunicando com os ativos na rede através do protocolo SNMP. Com essa solução, é possível modificar a ferramenta de modo a se adequar ao cenário à ser implantado, permitindo melhores resultados. O foco dos resultados é reduzir consideravelmente as ações corretivas e manter maior disponibilidade nos serviços críticos da empresa.

  9. Estudo de topologias para redes WDM-PON

    OpenAIRE

    Guilherme Enéas Vaz Silva

    2010-01-01

    A demanda de largura de banda exigida pelos usuários de redes de acesso vem aumentando rapidamente e a rede óptica passiva baseada em multiplexação por divisão de comprimento de onda (WDM-PON) tem se destacado como a tecnologia capaz de suprir essa demanda. Dessa forma, este trabalho conduz, inicialmente, uma comparação entre uma rede WDM-PON ideal e uma rede TDM-PON, discutindo também aspectos de segurança desta última, bem como estratégias de migração entre estes dois esquemas. Devido ao cu...

  10. Redes sociales de las mujeres mayores en dos contextos urbanos

    OpenAIRE

    González, M.M. (María)

    2009-01-01

    La enfermera de atención primaria es la responsable de la elaboración de un plan de cuidados adaptado a la población que atendemos,por lo que debe conocer las redes sociales de las personas ya que tener amplias redes puede significar la existencia de personas que ayuden con la medicación, las compras, la limpieza, mejora su seguridad y tienen apoyo en caso de urgencia. Este trabajo investiga esas redes sociales. Analizar las redes sociales de un grupo de mujeres mayores que viven en una i...

  11. SISTEMA PARA EL ENTRENAMIENTO PARALELO DE REDES NEURONALES DE PROPAGACIÓN HACIA ATRÁS

    Directory of Open Access Journals (Sweden)

    Alejandro Rosete Suárez

    2006-04-01

    Full Text Available

    El objetivo principal de este trabajo es la exploración del uso de la programación paralela en la instrumentación de redes neuronales, específicamente este artículo trata del uso de tal procesamiento para acelerar la fase de entrenamiento de una red de propagación hacia atrás (BPN. Se describe la implementación y los resultados obtenidos con la red neuronal antes mencionada. El sistema está realizado de manera tal, que el usuario pueda ejecutarlo eficientemente con un amplio rango de aplicaciones neuronales. Para probar el algoritmo paralelo implementado se utilizó una aplicación neuronal real y los resultados obtenidos muestran lo beneficioso de usar el entrenamiento paralelo.

  12. Natural - synthetic - artificial!

    DEFF Research Database (Denmark)

    Nielsen, Peter E

    2010-01-01

    The terms "natural," "synthetic" and "artificial" are discussed in relation to synthetic and artificial chromosomes and genomes, synthetic and artificial cells and artificial life.......The terms "natural," "synthetic" and "artificial" are discussed in relation to synthetic and artificial chromosomes and genomes, synthetic and artificial cells and artificial life....

  13. Uso de redes neuronales para optimizar simulaciones en un modelo de flujo de pasajeros en aeropuertos

    Directory of Open Access Journals (Sweden)

    Joaquin Pacheco

    2002-01-01

    Full Text Available Uno de nuestros principales objetivos es el diseño de métodos de aprendizaje de redes neuronales que sean rápidos a la vez que den buenas soluciones o vectores de pesos. Una de las aplicaciones donde se necesita un método rápido (on-line de aprendizaje de las redes neuronales es en la optimización de simulaciones. En este informe se proponen un sencillo algoritmo de búsqueda local para optimizar simulaciones, con una aplicación a un interesante modelo de flujo de pasajeros en un aeropuerto. En este problema se contemplan la minimización del tiempo de recorrido de los pasajeros con una adecuada distribución de los recursos. Este método incorpora el uso de una red neuronal para acelerar la optimización. Se va a comparar el efecto del uso de los pesos obtenidos por diferentes métodos de aprendizaje de la red neuronal, propuestos recientemente para este fin.

  14. Redes Neuronales Artificiales en la predicción de errores, aplicado a redes de computadoras

    OpenAIRE

    Aguilar Durán, Rosendo Arturo

    2002-01-01

    Las redes de computadoras son vitales para los negocios, ya que me permiten compartir y acceder información, además de tener una amplia comunicación con las personas, día a día el avance de la tecnología hace que las redes de computadoras tengan mayor velocidad por lo tanto sean mas complejas, todo esto conlleva a que administrarlas sea todo un reto. Para tener una buena administración no importando la complejidad de la misma, es necesario contar con ...

  15. Experiencia de intercambio docente en dos asignaturas de Inteligencia Artificial en universidades argentinas

    OpenAIRE

    Mariño, Sonia Itatí; Rambo, Alice

    2014-01-01

    En ámbitos de Educación Superior se propicia la generación de redes de intercambio y difusión de conocimientos y experiencias. Se describe una iniciativa docente desarrollada en dos asignaturas que abordan temas de Inteligencia Artificial.

  16. Artificial sweeteners

    DEFF Research Database (Denmark)

    Raben, Anne Birgitte; Richelsen, Bjørn

    2012-01-01

    Artificial sweeteners can be a helpful tool to reduce energy intake and body weight and thereby risk for diabetes and cardiovascular diseases (CVD). Considering the prevailing diabesity (obesity and diabetes) epidemic, this can, therefore, be an important alternative to natural, calorie-containin......Artificial sweeteners can be a helpful tool to reduce energy intake and body weight and thereby risk for diabetes and cardiovascular diseases (CVD). Considering the prevailing diabesity (obesity and diabetes) epidemic, this can, therefore, be an important alternative to natural, calorie......-containing sweeteners. The purpose of this review is to summarize the current evidence on the effect of artificial sweeteners on body weight, appetite, and risk markers for diabetes and CVD in humans....

  17. The straintronic spin-neuron

    International Nuclear Information System (INIS)

    Biswas, Ayan K; Bandyopadhyay, Supriyo; Atulasimha, Jayasimha

    2015-01-01

    In artificial neural networks, neurons are usually implemented with highly dissipative CMOS-based operational amplifiers. A more energy-efficient implementation is a ‘spin-neuron’ realized with a magneto-tunneling junction (MTJ) that is switched with a spin-polarized current (representing weighted sum of input currents) that either delivers a spin transfer torque or induces domain wall motion in the soft layer of the MTJ to mimic neuron firing. Here, we propose and analyze a different type of spin-neuron in which the soft layer of the MTJ is switched with mechanical strain generated by a voltage (representing weighted sum of input voltages) and term it straintronic spin-neuron. It dissipates orders of magnitude less energy in threshold operations than the traditional current-driven spin neuron at 0 K temperature and may even be faster. We have also studied the room-temperature firing behaviors of both types of spin neurons and find that thermal noise degrades the performance of both types, but the current-driven type is degraded much more than the straintronic type if both are optimized for maximum energy-efficiency. On the other hand, if both are designed to have the same level of thermal degradation, then the current-driven version will dissipate orders of magnitude more energy than the straintronic version. Thus, the straintronic spin-neuron is superior to current-driven spin neurons. (paper)

  18. Artificial Intelligence

    CERN Document Server

    Warwick, Kevin

    2011-01-01

    if AI is outside your field, or you know something of the subject and would like to know more then Artificial Intelligence: The Basics is a brilliant primer.' - Nick Smith, Engineering and Technology Magazine November 2011 Artificial Intelligence: The Basics is a concise and cutting-edge introduction to the fast moving world of AI. The author Kevin Warwick, a pioneer in the field, examines issues of what it means to be man or machine and looks at advances in robotics which have blurred the boundaries. Topics covered include: how intelligence can be defined whether machines can 'think' sensory

  19. Artificial intelligence

    International Nuclear Information System (INIS)

    Perret-Galix, D.

    1992-01-01

    A vivid example of the growing need for frontier physics experiments to make use of frontier technology is in the field of artificial intelligence and related themes. This was reflected in the second international workshop on 'Software Engineering, Artificial Intelligence and Expert Systems in High Energy and Nuclear Physics' which took place from 13-18 January at France Telecom's Agelonde site at La Londe des Maures, Provence. It was the second in a series, the first having been held at Lyon in 1990

  20. Developments in REDES: The Rocket Engine Design Expert System

    Science.gov (United States)

    Davidian, Kenneth O.

    1990-01-01

    The Rocket Engine Design Expert System (REDES) was developed at NASA-Lewis to collect, automate, and perpetuate the existing expertise of performing a comprehensive rocket engine analysis and design. Currently, REDES uses the rigorous JANNAF methodology to analyze the performance of the thrust chamber and perform computational studies of liquid rocket engine problems. The following computer codes were included in REDES: a gas properties program named GASP; a nozzle design program named RAO; a regenerative cooling channel performance evaluation code named RTE; and the JANNAF standard liquid rocket engine performance prediction code TDK (including performance evaluation modules ODE, ODK, TDE, TDK, and BLM). Computational analyses are being conducted by REDES to provide solutions to liquid rocket engine thrust chamber problems. REDES was built in the Knowledge Engineering Environment (KEE) expert system shell and runs on a Sun 4/110 computer.

  1. Spiking Neurons for Analysis of Patterns

    Science.gov (United States)

    Huntsberger, Terrance

    2008-01-01

    Artificial neural networks comprising spiking neurons of a novel type have been conceived as improved pattern-analysis and pattern-recognition computational systems. These neurons are represented by a mathematical model denoted the state-variable model (SVM), which among other things, exploits a computational parallelism inherent in spiking-neuron geometry. Networks of SVM neurons offer advantages of speed and computational efficiency, relative to traditional artificial neural networks. The SVM also overcomes some of the limitations of prior spiking-neuron models. There are numerous potential pattern-recognition, tracking, and data-reduction (data preprocessing) applications for these SVM neural networks on Earth and in exploration of remote planets. Spiking neurons imitate biological neurons more closely than do the neurons of traditional artificial neural networks. A spiking neuron includes a central cell body (soma) surrounded by a tree-like interconnection network (dendrites). Spiking neurons are so named because they generate trains of output pulses (spikes) in response to inputs received from sensors or from other neurons. They gain their speed advantage over traditional neural networks by using the timing of individual spikes for computation, whereas traditional artificial neurons use averages of activity levels over time. Moreover, spiking neurons use the delays inherent in dendritic processing in order to efficiently encode the information content of incoming signals. Because traditional artificial neurons fail to capture this encoding, they have less processing capability, and so it is necessary to use more gates when implementing traditional artificial neurons in electronic circuitry. Such higher-order functions as dynamic tasking are effected by use of pools (collections) of spiking neurons interconnected by spike-transmitting fibers. The SVM includes adaptive thresholds and submodels of transport of ions (in imitation of such transport in biological

  2. Laboratorio de Automatizaciones y Redes Industriales

    OpenAIRE

    Macias García, Manuel E.; Vallejo Guevara, Antonio Jr.

    2013-01-01

    Este proyecto es una iniciativa para el desarrollo de una solución de bajo costo a la necesidad de equipamiento de laboratorios, al implementar plataformas tecnológicas de vanguardia en innovación y tecnología educativa. El proyecto consiste en equipar un laboratorio de automatización y redes industriales con equipo industrial y empleo de máquinas de realidad virtual para entrenamiento local. Las máquinas de realidad virtual son modelos de maquinaria o procesos reales emulados por medio de so...

  3. Redes sociales y educación

    OpenAIRE

    Trujillo Torres, Juan Manuel

    2014-01-01

    De manera global, una red social es una organización social formada por personas o entidades vinculadas y unidas entre sí por algún tipo de estructura, relación o interés común. Se han convertido en un fenómeno global donde se establecen vínculos entre personas que comparten y establecen nodos relacionales que promueven la reciprocidad y la comunicación social, dando sentido a la red en sí misma. Tal y como afirman Castañeda y Gutiérrez (2010) las redes sociales (Social Networking Sites) son,...

  4. La escritura en las redes sociales

    OpenAIRE

    Lagneaux, Milagros

    2017-01-01

    Desde su surgimiento, las nuevas tecnologías modificaron distintas prácticas sociales y culturales. La escritura, más precisamente la escritura literaria, es también parte de un nuevo cambio de paradigma en el que nos vemos inmersos. La idea de este artículo es visibilizar cuáles son las nuevas prácticas actuales en relación a la lecto-escritura y cómo las redes sociales adquieren una participación fundamental para la producción, el desarrollo y la creación de estos nuevos contenidos. Cent...

  5. Los Protocolos en las redes de ordenadores

    OpenAIRE

    Salavert Casamor, Antonio

    2003-01-01

    El objetivo de este libro es dar a conocer los protocolos de las redes de datos y de los de comunicaciones directamente relacionados con los mismos. Con el fin de facilitar este conocimiento al mayor número de personas, independientemente de su grado de formación técnica sobre estos temas, la exposición de los mismos no es ni muy exhaustiva ni muy técnica, excepto en algunos protocolos concretos como pueden ser los de Internet. Las especificaciones de estos protocolos es pública y por tanto d...

  6. Redes sociales y sociedad del conocimiento

    OpenAIRE

    Vélez Cuartas, Gabriel Jaime

    2009-01-01

    Esta segunda edición de Innovación RICEC integra 5 de los artículos presentados en la mesa "Redes Sociales y Sociedad del Conocimiento" del "4to Congreso de Sistemas de Innovación para la Competitividad 2009: SINNCO" realizado por el CONCYTEG (Consejo de Ciencia y Tecnología de Guanajuato - México). Dos artículos sobre avances de investigación cercanas al concepto de controversia de Callon y por tanto al de teoría del actor red; y finalmente una reseña de la escuela de verano de la red intern...

  7. Redes de amistad, felicidad y familia

    Directory of Open Access Journals (Sweden)

    FÉLIX REQUENA SANTOS

    1994-01-01

    Full Text Available Usando los datos reticulares obtenidos de la encuesta de octubre de 1993 por "cires", se ha actualizado la relación entre felicidad, redes de amistad y relaciones familiares. Se pone de manifiesto que el gasto de felicidad aumenta con el número de amigos pero no con la intensidad de la amistad. Las relaciones más intensas las proporciona mejor la familia. Estos efectos se mantienen después de establecer diferencias según algunos atributos de los respondentes, como sexo, edad, religión. Sin embargo, este efecto se invierte cuando se controla por el "status" socioeconómico.

  8. Redes, cultura, e identidad en las organizaciones

    Directory of Open Access Journals (Sweden)

    Xavier Coller

    2002-01-01

    Full Text Available La interacción entre cultura y estructura informal de la organización tiene efectos diversos en la vida diaria de las instituciones. Algunos de ellos son el desarrollo de una cierta identidad organizativa y la aparición de relaciones de poder informal. Este artículo avanza varias líneas de investigación sobre estos dos aspectos aprovechando algunas de las aportaciones del análisis de redes. Los autores aventuran algunas hipótesis de trabajo que pueden ayudar a orientar investigaciones empíricas en el futuro.

  9. Artificial Intelligence.

    Science.gov (United States)

    Wash, Darrel Patrick

    1989-01-01

    Making a machine seem intelligent is not easy. As a consequence, demand has been rising for computer professionals skilled in artificial intelligence and is likely to continue to go up. These workers develop expert systems and solve the mysteries of machine vision, natural language processing, and neural networks. (Editor)

  10. Doubly stochastic Poisson processes in artificial neural learning.

    Science.gov (United States)

    Card, H C

    1998-01-01

    This paper investigates neuron activation statistics in artificial neural networks employing stochastic arithmetic. It is shown that a doubly stochastic Poisson process is an appropriate model for the signals in these circuits.

  11. Development of an artificial neural network for monitoring and diagnosis of sensor fault and detection in the IEA-R1 research reactor at IPEN; Utilizacao de redes neurais artificiais na monitoracao e deteccao de falhas em sensores do reator IEA-R1

    Energy Technology Data Exchange (ETDEWEB)

    Bueno, Elaine Inacio

    2006-07-01

    The increasing demand on quality in production processes has encouraged the development of several studies on Monitoring and Diagnosis Systems in industrial plant, where the interruption of the production due to some unexpected change can bring risk to the operator's security besides provoking economic losses, increasing the costs to repair some damaged equipment. Because of these two points, the economic losses and the operator's security, it becomes necessary to implement Monitoring and Diagnosis Systems. In this work, a Monitoring and Diagnosis Systems was developed based on the Artificial Neural Networks methodology. This methodology was applied to the IEA-R1 research reactor at IPEN. The development of this system was divided in three stages: the first was dedicated to monitoring, the second to the detection and the third to diagnosis of failures. In the first stage, several Artificial Neural Networks were trained to monitor the temperature variables, nuclear power and dose rate. Two databases were used: one with data generated by a theoretical model and another one with data to a typical week of operation of the IEA-R1 reactor. In the second stage, the neural networks used to monitor the variables was tested with a fault database. The faults were inserted artificially in the sensors signals. As the value of the maximum calibration error for special thermocouples is {+-}0,5 deg C, it had been inserted faults of {+-} 10 C in the sensors for the reading of the variables T3 and T4. In the third stage a Fuzzy System was developed to carry out the faults diagnosis, where were considered three conditions: a normal condition, a fault of {sub 1}0 C , and a fault of + 10 C . This system will indicate which thermocouple is faulty. (author)

  12. Arquitetura para interconexão entre fibra óptica e redes pessoais sem fio

    NARCIS (Netherlands)

    Huiszoon, B.; Fledderus, E.; Khoe, G.D.; Waardt, de H.; Koonen, A.M.J.

    2007-01-01

    A necessidade de maior largura de banda, combinada com o aumento da busca por mobilidade, requer novos conceitos de interconexao de redes. Neste artigo e discutido o conceito de rede pessoal, uma rede inerentemente movel mas que necessita da rede de acesso como backbone de banda larga. O autor

  13. Artificial Consciousness or Artificial Intelligence

    Directory of Open Access Journals (Sweden)

    Spanache Florin

    2017-05-01

    Full Text Available Artificial intelligence is a tool designed by people for the gratification of their own creative ego, so we can not confuse conscience with intelligence and not even intelligence in its human representation with conscience. They are all different concepts and they have different uses. Philosophically, there are differences between autonomous people and automatic artificial intelligence. This is the difference between intelligence and artificial intelligence, autonomous versus automatic. But conscience is above these differences because it is neither conditioned by the self-preservation of autonomy, because a conscience is something that you use to help your neighbor, nor automatic, because one’s conscience is tested by situations which are not similar or subject to routine. So, artificial intelligence is only in science-fiction literature similar to an autonomous conscience-endowed being. In real life, religion with its notions of redemption, sin, expiation, confession and communion will not have any meaning for a machine which cannot make a mistake on its own.

  14. Experimentos con una protección basada en redes de neuronas artificiales

    Directory of Open Access Journals (Sweden)

    Orlys Ernesto Torres Breffe

    2011-10-01

    Full Text Available En este trabajo se muestran los resultados de los experimentos físicos realizados con una protección basada totalmente en Redes de Neuronas Artificiales para un transformador eléctrico a escala de laboratorio. Se demuestra que unas Redes de Neuronas Artificiales entrenadas, con datos provenientes de regímenes simulados matemáticamente, opera correctamente con señales de regímenes provenientes de casos reales, al menos a escala de laboratorio y con niveles reducidos de intensidad. Se describe la instalación experimental, tanto desde el puntode vista de hardware como software utilizando la tecnología de National Instrument. Se entrenan diferentes tipos de Redes Neuronales y todas aprendieron a proteger correctamente. Estos experimentos establecen las pautas para el desarrollo de Relés Electrónicos Inteligentes que no se ajustarían, al menos con datos y valores de difícil comprensión como los actuales relés, sino que se entrenarían una vez mediante la simulación matemática y la experiencia práctica los haría cada vez mejores. In this work is shown the results of the physical experiments done with a protection totally based in Artificial Neural Networks for an electric transformer of the laboratory scale. Its demonstrated that some Artificial Neural Networks trained with data coming from a mathematically simulated regimens, it operates correctly with signals coming fromreal cases, at least to laboratory scale and with reduced levels of intensity. The experimental installation is described, so much from the hardware and software point of view, using the technology of National Instrument. Different types of Artificial Neural Nets are trained and all learned how to protect correctly. These experiments establish the rules forthe development of Intelligent Electronic Relays that would not be adjusted, at least with complex data and values like the current relays, they will be trained once from the mathematically simulation and the

  15. Artificial Intelligence.

    Science.gov (United States)

    Lawrence, David R; Palacios-González, César; Harris, John

    2016-04-01

    It seems natural to think that the same prudential and ethical reasons for mutual respect and tolerance that one has vis-à-vis other human persons would hold toward newly encountered paradigmatic but nonhuman biological persons. One also tends to think that they would have similar reasons for treating we humans as creatures that count morally in our own right. This line of thought transcends biological boundaries-namely, with regard to artificially (super)intelligent persons-but is this a safe assumption? The issue concerns ultimate moral significance: the significance possessed by human persons, persons from other planets, and hypothetical nonorganic persons in the form of artificial intelligence (AI). This article investigates why our possible relations to AI persons could be more complicated than they first might appear, given that they might possess a radically different nature to us, to the point that civilized or peaceful coexistence in a determinate geographical space could be impossible to achieve.

  16. Artificial intelligence

    OpenAIRE

    Duda, Antonín

    2009-01-01

    Abstract : Issue of this work is to acquaint the reader with the history of artificial inteligence, esspecialy branch of chess computing. Main attention is given to progress from fifties to the present. The work also deals with fighting chess programs against each other, and against human opponents. The greatest attention is focused on 1997 and duel Garry Kasparov against chess program Deep Blue. The work is divided into chapters according to chronological order.

  17. Artificial heart

    Energy Technology Data Exchange (ETDEWEB)

    1984-10-18

    Super-pure plutonium-238 could use heat produced during fission to power an implanted artificial heart. Three model hearts have worked for some time. Concern that excess heat would make the procedure unsafe for humans has broadened the search for another energy source, such as electrohydraulic drive or an external power battery. A back pack approach may provide an interim solution until materials are developed which can withstand heart activity and be small enough for implantation.

  18. Pronóstico del IPC de la Bolsa Mexicana de Valores Mediante el Uso de Reglas y Redes Neuronales

    OpenAIRE

    Cázares Carrillo, Juan G.

    2004-01-01

    La presente investigación es un esfuerzo para el desarrollo de un pronosticador con resultados aceptables para el mercado de valores destinándose su uso como una herramienta de apoyo a la toma de decisiones financieras. El pronóstico se realiza mediante la identificación de patrones utilizando como herramientas técnicas de Inteligencia Artificial, específicamente Redes Neuronales de Retropropagación y Algoritmos Genéticos. Las principales aportaciones de la presente investigación son: la dete...

  19. Minería de datos en redes educativas

    OpenAIRE

    Sosa, Marcelo Omar; Sosa Bruchmann, Eugenia C.; Vega, Raúl Marcelo

    2013-01-01

    La minería de datos (data mining) viene ampliando sus áreas de aplicación, demostrando la validez de sus descripciones y predicciones en el análisis de datos. Las nuevas áreas en las que se vienen desarrollando estudios se relacionan directamente con el fenómeno de los últimos años como son las redes sociales. Siguiendo las características de estas últimas se crearon redes como lo son las redes educativas, las que se conforman en estratos académicos, que pueden ser de tamaño muy grandes si se...

  20. Seguridad en redes inalámbricas 802.11

    OpenAIRE

    Madrid Molina, Juan Manuel

    2006-01-01

    La falta de seguridad en las redes inalámbricas es un problema que, a pesar de su gravedad, no ha recibido la atención debida por parte de los administradores de redes y los responsablesde la información. Este artículo presenta las tecnologías existentes para mejorar el nivel de seguridad en las redes inalámbricas 802.11, con sus ventajas, desventajas y escenarios de aplicación. Lack of security in wireless LANs is a problem which has not been correctly assessed by network managers ...

  1. Las relaciones empresariales: una tipología de redes

    OpenAIRE

    José Luis Galán; Cristóbal Casanueva; Ignacio Castro-Abancéns

    2010-01-01

    El conjunto de redes en las que participan las empresas son consideradas como un recurso para las mismas. Cada empresa participa en redes diferentes y su posición en cada red la hace diferente a las demás. Las relaciones de una empresa se comportan como un recurso que está en la base de la heterogeneidad que le permite ser soporte de una ventaja competitiva sostenible. Sin embargo, el análisis de las redes empresariales es complejo. Este trabajo pretende disminuir esa complejidad analiz...

  2. Monitoramento e incentivos em redes de franquias brasileiras

    OpenAIRE

    Bianca Maria da Silva

    2015-01-01

    Redes de franquia constituem um tipo de arranjo híbrido de governança onde, normalmente, lojas próprias e franqueadas operam sob uma mesma marca e formato de negócios. Considerando que taxas de franquia (fixas e variáveis) estão entres as principais fontes de receita do franqueador senão a principal, este trabalho tem por objetivo identificar evidências quanto a fixação destas taxas por redes de franquia. A variação de tais taxas é comparada à capacidade de monitoramento das redes, consideran...

  3. Empleo de redes neuronales artificiales en redes de distribución eléctrica

    OpenAIRE

    Alexander Cabrera; Delmar Jaime; Dante Miraglia; Sergio de la Fé Dotres

    2011-01-01

    En el trabajo se muestran las experiencias alcanzadas  en la aplicación de las Redes Neuronales Artificiales para resolver problemas tales como  la predicción de carga y de pérdidas de energía en las líneas y la localización de zonas en falla en circuitos de distribución de la ciudad de Santiago de Cuba.

  4. Redes de pequenas empresas: a aplicação de uma tipologia em uma rede de supermercados.

    Directory of Open Access Journals (Sweden)

    Rivanda Meira Teixeira

    2007-09-01

    Full Text Available O presente estudo teve como objetivo analisar as características de uma rede do setor de comércio varejista, a Rede Econômica de Supermercados, de acordo com a tipologia de redes de empresas proposta por Hoffmann et al. (2004. Além disso, buscou-se identificar quais são os principais benefícios e dificuldades verificados na operacionalização da Rede. A partir de entrevistas realizadas com o gestor administrativo da Rede e com um gerente de compras, e com base na análise de documentos e material institucional, pode-se classificar a Rede como de cooperação horizontal, aglomerada, formal e não-orbital. As principais vantagens percebidas para os supermercados, com relação à participação na rede, foram a realização de ações de marketing e de compras conjuntas. A principal dificuldade apontada reside na conciliação dos objetivos do negócio com os objetivos individuais.

  5. Redes Corporativas Inmersivas. Nuevas formas de uso de las redes sociales

    Directory of Open Access Journals (Sweden)

    Jorge E. Giménez Hernando

    2011-07-01

    Full Text Available Las redes sociales se están imponiendo como forma de comunicación a través de Internet sobre cualesquiera otros formatos tradicionales, llegando incluso a eclipsar el más reciente y universal correo electrónico. De entre sus múltiples aplicaciones, destacan desde el punto de vista empresarial las redes sociales corporativas, que se conciben como un vehículo extraordinariamente eficaz para transferir el conocimiento que aporte a la compañía ventaja competitiva para posicionarse y operar en el mercado.Por otra parte, el auge del desarrollo de las nuevas tecnologías basadas en 3D, los mundos virtuales o la realidad aumentada, que se ha basado en los últimos años en entornos lúdicos y de esparcimiento, está comenzando a aplicarse a otro tipo de contenidos, que se intentan aprovechar de su realismo y motivación.El presente artículo presenta la realización de una experiencia piloto en que se han aunado ambos conceptos, aplicando las tecnologías de mundos virtuales a las redes sociales corporativas, y permitiendo la comparación de los resultados obtenidos con los acumulados en experiencias anteriores de acceso web tradicional. Dicha comparación se ha basado en las encuestas realizadas a los usuarios tras la experiencia piloto.

  6. Artificial intelligence in hematology.

    Science.gov (United States)

    Zini, Gina

    2005-10-01

    Artificial intelligence (AI) is a computer based science which aims to simulate human brain faculties using a computational system. A brief history of this new science goes from the creation of the first artificial neuron in 1943 to the first artificial neural network application to genetic algorithms. The potential for a similar technology in medicine has immediately been identified by scientists and researchers. The possibility to store and process all medical knowledge has made this technology very attractive to assist or even surpass clinicians in reaching a diagnosis. Applications of AI in medicine include devices applied to clinical diagnosis in neurology and cardiopulmonary diseases, as well as the use of expert or knowledge-based systems in routine clinical use for diagnosis, therapeutic management and for prognostic evaluation. Biological applications include genome sequencing or DNA gene expression microarrays, modeling gene networks, analysis and clustering of gene expression data, pattern recognition in DNA and proteins, protein structure prediction. In the field of hematology the first devices based on AI have been applied to the routine laboratory data management. New tools concern the differential diagnosis in specific diseases such as anemias, thalassemias and leukemias, based on neural networks trained with data from peripheral blood analysis. A revolution in cancer diagnosis, including the diagnosis of hematological malignancies, has been the introduction of the first microarray based and bioinformatic approach for molecular diagnosis: a systematic approach based on the monitoring of simultaneous expression of thousands of genes using DNA microarray, independently of previous biological knowledge, analysed using AI devices. Using gene profiling, the traditional diagnostic pathways move from clinical to molecular based diagnostic systems.

  7. Redes sociales en las bibliotecas escolares

    Directory of Open Access Journals (Sweden)

    Vicent Giménez Chornet

    2015-04-01

    Full Text Available Las bibliotecas escolares deben ser un medio para acceder al conocimiento, y las Tecnologías de la Información y la Comunicación pueden facilitar que los estudiantes adolescentes se inicien en el uso de estas tecnologías para desarrollar sus capacidades y habilidades en la búsqueda de información. Las redes sociales e Internet preocupan por las situaciones problemáticas que pueden provocar en los niños y adolescentes que no sean conscientes de los peligros de la red, pero ello no debe impedir que conozcan las ventajas que las TIC ofrecen como forma y medio de aprender. En el artículo se analizan diferentes propuestas innovadoras que se han implantado en distintas bibliotecas escolares del mundo. Se concluye que es importante que los estudiantes preuniversitarios conozcan y dominen estas herramientas antes de incorporarse al mundo laboral o a la universidad.

  8. Motor Neurons

    DEFF Research Database (Denmark)

    Hounsgaard, Jorn

    2017-01-01

    Motor neurons translate synaptic input from widely distributed premotor networks into patterns of action potentials that orchestrate motor unit force and motor behavior. Intercalated between the CNS and muscles, motor neurons add to and adjust the final motor command. The identity and functional...... in in vitro preparations is far from complete. Nevertheless, a foundation has been provided for pursuing functional significance of intrinsic response properties in motoneurons in vivo during motor behavior at levels from molecules to systems....

  9. Reciclando a cidadania em rede interdisciplinar

    Directory of Open Access Journals (Sweden)

    Foresti, Andréa Jaeger

    2006-01-01

    Full Text Available Este texto tem por objetivo evidenciar o processo de constituição da ONG REDECRIAR, diretamente vinculada ao Projeto “Reciclando a Cidadania em Rede Interdisciplinar”, examinando os elementos que nele estão imbricados. O primeiro elemento se refere ao chamado Terceiro Setor, o qual se configurou como espaço de intervenção profissional, viabilizando a articulação de conhecimentos interdisciplinares, norteados por princípios éticos e políticos, que buscam garantir a universalidade das políticas sociais públicas. O segundo elemento a ser examinado é o Desenvolvimento Sustentável que se conformou como tema central das ações planejadas por abarcar, em seu conceito, o equilíbrio entre as questões ambientais, sociais e econômicas. Esta conformação determinou a efetividade da proposta, ao delinear o conteúdo das intervenções, direcionado a um públicoalvo coletivo. Nessa perspectiva, a implementação dos pressupostos metodológicos do Trabalho, em Redes Sociais, constitui-se como terceiro elemento imbricado no processo de constituição da REDECRIAR, corroborando com a reciclagem – aproximação prática de um novo conceito – da Cidadania, efetivado por um grupo de profissionais do Serviço Social, Biologia e Nutrição

  10. Artificial graphites

    International Nuclear Information System (INIS)

    Maire, J.

    1984-01-01

    Artificial graphites are obtained by agglomeration of carbon powders with an organic binder, then by carbonisation at 1000 0 C and graphitization at 2800 0 C. After description of the processes and products, we show how the properties of the various materials lead to the various uses. Using graphite enables us to solve some problems, but it is not sufficient to satisfy all the need of the application. New carbonaceous material open application range. Finally, if some products are becoming obsolete, other ones are being developed in new applications [fr

  11. Determination of volume fraction in biphasic flows oil-gas and water-gas using artificial neural network and gamma densitometry; Determinacao de fracoes de volume em fluxos bifasicos oleo-gas e agua-gas utilizando redes neurais artificiais e densitometria gama

    Energy Technology Data Exchange (ETDEWEB)

    Peixoto, Philippe Netto Belache

    2016-07-01

    This study presents a methodology based on the principles of gamma ray attenuation to identify volume fractions in biphasic systems composed of oil-gas-water and gas which are found in the offshore oil industry. This methodology is based on the acknowledgment counts per second on the photopeak energy using a detection system composed of a NaI (Tl) detector, a source of {sup 137}Cs without collimation positioned at 180 ° relative to the detector on a smooth stratified flow regime. The mathematical modeling for computational simulation using the code MCNP-X was performed using the experimental measurements of the detector characteristics (energy resolution and efficiency), characteristics of the material water and oil (density and coefficient attenuation) and measurement of the volume fractions. To predict these fractions were used artificial neural networks (ANNs), and to obtain an adequate training the ANNs for the prediction of volume fractions were simulated a larger number of volume fractions in MCNP-X. The experimental data were used in the set data necessary for validation of ANNs and the data generated using the computer code MCNP-X were used in training and test sets of the ANNs. Were used ANNs of type feed-forward Multilayer Perceptron (MLP) and analyzed two functions of training, Levenberg-Marquardt (LM) and gradient descent with momentum (GDM), both using the Backpropagation training algorithm. The ANNs identified correctly the volume fractions of the multiphase system with mean relative errors lower than 1.21 %, enabling the application of this methodology for this purpose. (author)

  12. Control neuronal predictivo por linealización instantánea

    Directory of Open Access Journals (Sweden)

    Rosalba Lamanna

    2007-04-01

    Full Text Available Resumen: Se desarrolla un esquema de Control Predictivo Generalizado (GPC basado en un modelo neuronal del proceso, y se aplica en un reactor de neutralización de laboratorio. El modelo neuronal se obtiene previamente por identificación, y se linealiza en cada iteración del algoritmo de control. De esta manera se combina la capacidad de ajuste de la redes neuronales con la eficiencia de cálculo del GPC, consiguiéndose un sistema con las ventajas del control predictivo pero extendido a sistemas no lineales, que se comporta con precisión y rapidez ante perturbaciones. Palabras clave: Control Neuronal, Control Predictivo, Redes Neuronales, Linealización Instantánea, Control de pH

  13. Detecting and classifying faults on transmission systems using a backpropagation neural network; Deteccion y clasificacion de fallas en sistemas de transmision empleando una red neuronal con retropropagacion del error

    Energy Technology Data Exchange (ETDEWEB)

    Rosas Ortiz, German

    2000-01-01

    Fault detection and diagnosis on transmission systems is an interesting area of investigation to Artificial Intelligence (AI) based systems. Neurocomputing is one of fastest growing areas of research in the fields of AI and pattern recognition. This work explores the possible suitability of pattern recognition approach of neural networks for fault detection and classification on power systems. The conventional detection techniques in modern relays are based in digital processing of signals and it need some time (around 1 cycle) to send a tripping signal, also they are likely to make incorrect decisions if the signals are noisy. It's desirable to develop a fast, accurate and robust approach that perform accurately for changing system conditions (like load variations and fault resistance). The aim of this work is to develop a novel technique based on Artificial Neural Networks (ANN), which explores the suitability of a pattern classification approach for fault detection and diagnosis. The suggested approach is based in the fact that when a fault occurs, a change in the system impedance take place and, as a consequence changes in amplitude and phase of line voltage and current signals take place. The ANN-based fault discriminator is trained to detect this changes as indicators of the instant of fault inception. This detector uses instantaneous values of these signals to make decisions. Suitability of using neural network as pattern classifiers for transmission systems fault diagnosis is described in detail a neural network design and simulation environment for real-time is presented. Results showing the performance of this approach are presented and indicate that it is fast, secure and exact enough, and it can be used in high speed fault detection and classification schemes. [Spanish] El diagnostico y la deteccion de fallas en sistemas de transmision es una area de interes en investigacion para sistemas basados en Inteligencia Artificial (IA). El calculo neuronal

  14. [Mirror neurons].

    Science.gov (United States)

    Rubia Vila, Francisco José

    2011-01-01

    Mirror neurons were recently discovered in frontal brain areas of the monkey. They are activated when the animal makes a specific movement, but also when the animal observes the same movement in another animal. Some of them also respond to the emotional expression of other animals of the same species. These mirror neurons have also been found in humans. They respond to or "reflect" actions of other individuals in the brain and are thought to represent the basis for imitation and empathy and hence the neurobiological substrate for "theory of mind", the potential origin of language and the so-called moral instinct.

  15. Búsqueda de recursos en redes peer-to-peer totalmente descentralizadas basada en redes neuronales artificiales

    OpenAIRE

    Corbalán, Leonardo César

    2014-01-01

    Las redes Peer-to-Peer (P2P) puras no estructuradas como Gnutella, dónde los nodos se conectan entre sí como pares o iguales, sin roles diferenciados ni jerarquías de ninguna clase, son sistemas distribuidos, dinámicos, sin punto alguno de centralización, que favorecen la robustez y tolerancia a fallos. Sin embargo, la búsqueda de recursos en estos sistemas constituye un problema esencial. El algoritmo de búsqueda BFS de Gnutella genera gran cantidad de tráfico dificultando su escalabilidad. ...

  16. Estado, redes cívicas y redes informales: Aportes para un debate

    OpenAIRE

    Alexei Guerra Sotillo

    2006-01-01

    El presente trabajo, con base en el análisis o enfoque de redes, sustentado metodológicamente en la revisión de literatura académica generada en torno a la temática, intenta desarrollar la tesis según la cual la sociedad civil y la economía informal representan fuerzas o movimientos complejos en la red social, de acercamiento y alejamiento a la gestión de lo público y al Estado. La interacción de estos tres ámbitos evidencia un esquema novedoso y contradictorio de relaciones ...

  17. Redes sociales y partidos políticos en Chile.

    Directory of Open Access Journals (Sweden)

    Adler Lomnitz, Larissa

    2002-09-01

    Full Text Available En este estudio se describe el origen y la evolución de dos partidos políticos chilenos (el Partido Radical y el Partido Demócrata Cristiano por medio del análisis de las redes sociales que los originaron y que los componen. Se propone un modelo teórico que consiste en la combinación de un análisis estructural basado en el estudio de redes sociales y en la descripción del sistema simbólico que las retroalimenta. La estructura y función de las redes sociales depende de la dirección en la que se dan los intercambios -redes horizontales y redes verticales-, de lo que se intercambia, y de la articulación que se da entre las redes. En toda sociedad se dan intercambios simétricos y asimétricos, que van conformando redes horizontales y verticales. Estas redes se van articulando entre sí, conformando el tejido social. El predominio de unas sobre otras y su combinación dan el carácter a la cultura política (ejemplo, autoritaria vs. igualitaria. En el caso de Chile encontramos que se trata de una sociedad horizontalmente estructurada en clases sociales, al interior de las cuales se advierten redes sociales informales que eventualmente y por razones ideológicas se van formalizando en partidos políticos. Estos grupos igualitarios de amigos ejercen informalmente control sobre sus propios miembros creando barreras invisibles que los distinguen de los demás, y aunque si bien es cierto que en ellos surgen líderes “naturales”, su liderazgo es condicional lo que permite el surgimiento de tendencias y facciones que a su vez pueden llegar a constituirse en nuevos partidos. Por ende, el sistema depende de negociaciones horizontales permanentes mediadas por un fuerte presidencialismo dentro de un sistema parlamentario fuerte y apoyado por una legitimidad casi fanática.

  18. REDES SOCIALES: APROXIMACIÓN A UN ESTADO DEL ARTE

    Directory of Open Access Journals (Sweden)

    Monsalve-Gómez, Juan Carlos

    2013-06-01

    Full Text Available Este artículo presenta una revisión de estado del arte sobre las redes sociales, con una aproximación a aspectos relacionados con su impacto en el ámbito educativo, con un énfasis especial en la red social Facebook debido al crecimiento que esta ha tenido en los últimos años. El uso de las redes sociales es cada vez más difundido en el ámbito educativo y es importante, atendiendo a esta realidad, realizar estudios sobre sus posibilidades de uso, impacto y aspectos a mejorar. El texto presenta diferentes miradas de las redes sociales: como espacios de comunicación, su uso en diferentes niveles educativos, espacios de trabajo colaborativo, como apoyo a la investigación y la formación de maestros, entre otros, y realiza, al final, un análisis sobre los diferentes usos de las redes sociales en el ámbito educativo y, para terminar, un análisis sobre el uso de aplicativos educativos al interior de las redes sociales.

  19. Neural networks and statistical analysis for classification of corneal videokeratography maps based on Zernike coefficients: a quantitative comparison Redes neurais e análise estatística para classificação de mapas topográficos da córnea baseados em coeficientes de Zernike: uma comparação quantitativa

    Directory of Open Access Journals (Sweden)

    Luis Alberto Vieira de Carvalho

    2008-06-01

    Full Text Available PURPOSE: The main goal of this study was to develop and compare two different techniques for classification of specific types of corneal shapes when Zernike coefficients are used as inputs. A feed-forward artificial Neural Network (NN and discriminant analysis (DA techniques were used. METHODS: The inputs both for the NN and DA were the first 15 standard Zernike coefficients for 80 previously classified corneal elevation data files from an Eyesys System 2000 Videokeratograph (VK, installed at the Departamento de Oftalmologia of the Escola Paulista de Medicina, São Paulo. The NN had 5 output neurons which were associated with 5 typical corneal shapes: keratoconus, with-the-rule astigmatism, against-the-rule astigmatism, "regular" or "normal" shape and post-PRK. RESULTS: The NN and DA responses were statistically analyzed in terms of precision ([true positive+true negative]/total number of cases. Mean overall results for all cases for the NN and DA techniques were, respectively, 94% and 84.8%. CONCLUSION: Although we used a relatively small database, results obtained in the present study indicate that Zernike polynomials as descriptors of corneal shape may be a reliable parameter as input data for diagnostic automation of VK maps, using either NN or DA.OBJETIVOS: Nosso principal objetivo neste trabalho foi de desenvolver e comparar duas técnicas diferentes para classificação de superfícies corneanas. Uma rede neural artificial alimentada adiante e análise descriminante foram as técnicas de classificação comparadas neste trabalho. MÉTODOS: As entradas para ambos os métodos de classificação foram os primeiros 15 coeficientes de Zernike para 80 córneas mensuradas anteriormente em um topógrafo Eyesys instalado no Departamento de Oftalmologia da Escola Paulista de Medicina - UNIFESP. A rede neural tem 5 saídas que foram associados aos cinco casos típicos contidos na base de dados: ceratocone, astigmatismo a favor da regra, astigmatismo

  20. Behavioral plasticity through the modulation of switch neurons.

    Science.gov (United States)

    Vassiliades, Vassilis; Christodoulou, Chris

    2016-02-01

    A central question in artificial intelligence is how to design agents capable of switching between different behaviors in response to environmental changes. Taking inspiration from neuroscience, we address this problem by utilizing artificial neural networks (NNs) as agent controllers, and mechanisms such as neuromodulation and synaptic gating. The novel aspect of this work is the introduction of a type of artificial neuron we call "switch neuron". A switch neuron regulates the flow of information in NNs by selectively gating all but one of its incoming synaptic connections, effectively allowing only one signal to propagate forward. The allowed connection is determined by the switch neuron's level of modulatory activation which is affected by modulatory signals, such as signals that encode some information about the reward received by the agent. An important aspect of the switch neuron is that it can be used in appropriate "switch modules" in order to modulate other switch neurons. As we show, the introduction of the switch modules enables the creation of sequences of gating events. This is achieved through the design of a modulatory pathway capable of exploring in a principled manner all permutations of the connections arriving on the switch neurons. We test the model by presenting appropriate architectures in nonstationary binary association problems and T-maze tasks. The results show that for all tasks, the switch neuron architectures generate optimal adaptive behaviors, providing evidence that the switch neuron model could be a valuable tool in simulations where behavioral plasticity is required. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Computational Models of Neuron-Astrocyte Interactions Lead to Improved Efficacy in the Performance of Neural Networks

    Science.gov (United States)

    Alvarellos-González, Alberto; Pazos, Alejandro; Porto-Pazos, Ana B.

    2012-01-01

    The importance of astrocytes, one part of the glial system, for information processing in the brain has recently been demonstrated. Regarding information processing in multilayer connectionist systems, it has been shown that systems which include artificial neurons and astrocytes (Artificial Neuron-Glia Networks) have well-known advantages over identical systems including only artificial neurons. Since the actual impact of astrocytes in neural network function is unknown, we have investigated, using computational models, different astrocyte-neuron interactions for information processing; different neuron-glia algorithms have been implemented for training and validation of multilayer Artificial Neuron-Glia Networks oriented toward classification problem resolution. The results of the tests performed suggest that all the algorithms modelling astrocyte-induced synaptic potentiation improved artificial neural network performance, but their efficacy depended on the complexity of the problem. PMID:22649480

  2. Mediología, icono, redes sociales digitales.

    OpenAIRE

    Prado Flores, Rogelio del

    2016-01-01

    En el presente trabajo se abordan los temas de la mediología y las redes sociales digitales. Se analizan las categorías de icono digital, de lo virtual, de la interacción en las redes sociales digitales, con el apoyo de la hermenéutica analógica, la deconstrucción, la ética y la sociología desde el enfoque de un realismo crítico. Analizo el tipo de interacción que acontece en las redes sociales digitales y sus efectos en el tejido social, con la intención de invitar a un uso prudente y respon...

  3. Atrapados en las redes de migración.

    OpenAIRE

    Zavala Sánchez, Fabiola Mayteé

    2013-01-01

    “Atrapados en las redes de la migración” pretende ser un estudio del fenómeno migratorio en el Ecuador, en el cual se investiga el proceso de la construcción de redes sociales migratorias. Con esta investigación se pretende determinar cómo las redes transnacionales de migración se construyen y transforman, pero sobre todo se tratará de conocer cuáles son los actores que en ellas intervienen, cuáles son sus roles y funciones. El estudio se lo realizará a través de una microinvestigación, me...

  4. Aspectos legales al utilizar las principales redes sociales en Colombia

    Directory of Open Access Journals (Sweden)

    Manuel Adolfo Alvarado Carmona

    2017-01-01

    Full Text Available Se analizaron los aspectos legales al utilizar las dos principales redes sociales en Colombia como los son facebook y twitter. Cuando un usuario se conecta a cualquiera de las redes sociales debe hacerlo de forma responsable porque de lo contrario puede incurrir en la violación de la normatividad Colombiana en la cual se encuentran los delitos informáticos, la protección de la información y los datos, injuria y calumnia, ciberacoso y derechos de autor. Se determinaron los problemas que conllevan cuando no se utiliza bien la información en las redes sociales en el ámbito jurídico.

  5. As Redes Sociais no Sector primário

    OpenAIRE

    Areias, Marcos André Caetano

    2013-01-01

    Dissertação apresentada como requisito parcial para obtenção do grau de Mestre em Estatística e Gestão de Informação A dissertação que de seguida será apresentada enquadra-se no âmbito da importância das redes sociais, enquanto factor de utilização e de trabalho no sector primário. Como tal, tem como objectivo estudar e aprofundar o conhecimento da utilização das redes sociais no sector primário. Desta forma, a dissertação foca-se no estudo das redes sociais no sector primário de três p...

  6. [Artificial intelligence in psychiatry-an overview].

    Science.gov (United States)

    Meyer-Lindenberg, A

    2018-06-18

    Artificial intelligence and the underlying methods of machine learning and neuronal networks (NN) have made dramatic progress in recent years and have allowed computers to reach superhuman performance in domains that used to be thought of as uniquely human. In this overview, the underlying methodological developments that made this possible are briefly delineated and then the applications to psychiatry in three domains are discussed: precision medicine and biomarkers, natural language processing and artificial intelligence-based psychotherapeutic interventions. In conclusion, some of the risks of this new technology are mentioned.

  7. Ensinar e aprender geografia com/nas redes sociais

    Directory of Open Access Journals (Sweden)

    Élida Pasini Tonetto

    2015-01-01

    Full Text Available Este estudo trata de refletir sobre as potencialidades/operacionalidades das práticas pedagógicas da Geografia na apropriação das redes sociais online. Para isso, analisamos possíveis potencialidades oferecidas pelas redes sociais online para a Geografia e como podem ser operacionalizadas nas práticas pedagógicas com as redes sociais online seu ensino e, também, pensar como elas podem contribuir para ensinar e aprender com mais significância Geografia. Os fios teóricos da pesquisa estão tramados no entendimento de aprendizagem online para emaranhar os conceitos de espaço e ciberespaço, transitando por dois locais fundamentais: o da escola e o das redes. A abordagem metodológica é construída nas trilhas das pesquisas pós-críticas em educação, onde o Facebook é o lócus para analisar as novas formas de comunicar que subjetivam os sujeitos e engendram novos formatos de ensinagem. Os resultados apontam diferentes potencialidades e operacionalidades das redes sociais online, mas que não representam apenas o uso da técnica em sala de aula, mas sim como parte da agenda de busca pela construção de processos de aprendizagens significativos em Geografia, através das redes sociais, que representam uma forma contemporânea de comunicar/interagir presente no cotidiano dos alunos.

  8. Estudio de los Tweens y las Redes Sociales, Tacna, 2016.

    OpenAIRE

    Mamani Mamani, Deysi Gaby; Gonzalo Jara, Gustavo Richard; Yufra Tozo, Wilfredo Renato

    2016-01-01

    La tesis propuesta en las siguientes páginas: “Estudio de los Tweens y las Redes Sociales, Tacna, 2016”, busca poner en evidencia las preferencias, razones de uso, y uso, de las redes sociales por parte del grupo etario conformado por los tweens o pre adolescentes (Niños entre 8 y 12 años). La investigación presentada es de carácter descriptivo, de diseño no experimental y transversal, y se llevó a cabo aplicando un cuestionario (Asistido), conformado por 11 preguntas, a 146 niños entre la...

  9. Sistemas de Inteligencia Web basados en redes sociales

    OpenAIRE

    Rosa Troyano, Fco. Fernando de la; Martínez Gasca, Rafael

    2007-01-01

    El Análisis de las Redes Sociales (ARS) es un área que está emergiendo como imprescindible en los procesos de toma de decisiones. Su capacidad para analizar e intervenir una red social puede ser aprovechada para implantar tareas de vigilancia en los sistemas de inteligencia de un centro de investigación o una empresa de base tecnológica. El objetivo de este trabajo es realizar una propuesta para diseñar sistemas de inteligencia web basados en redes sociales. El primer obstáculo para implantar...

  10. Sistemas de Inteligencia Web basados en Redes Sociales

    OpenAIRE

    de la Rosa Troyano, Fco. Fernando; Martínez Gasca, Rafael

    2007-01-01

    El Análisis de las Redes Sociales (ARS) es un área que está emergiendo como imprescindible en los procesos de toma de decisiones. Su capacidad para analizar e intervenir una red social puede ser aprovechada para implantar tareas de vigilancia en los sistemas de inteligencia de un centro de investigación o una empresa de base tecnológica. El objetivo de este trabajo es realizar una propuesta para diseñar sistemas de inteligencia web basados en redes sociales. El primer obstáculo para implantar...

  11. Redes sociales y el ciberbullying en la Universidad Veracruzana

    OpenAIRE

    Dorantes Carrión, Jeysira Jacqueline

    2017-01-01

    Este trabajo es parte de una investigación desarrollada en la Universidad Veracruzana, en donde se estudió al ciberbullying como fenómeno que se ejerce entre estudiantes universitarios a través de las redes sociales. El objetivo es dar a conocer cómo se desarrollan acciones violentas como la ofensa, la intimidación, la exhibición en el interior de los espacios universitarios a partir del mal uso de las redes sociales. Estos actos afectan la sociedad, sus individuos, las familias, así como las...

  12. Visualización de redes personales en Sarajevo

    OpenAIRE

    Aguilar Carretero, Claudia

    2005-01-01

    El concepto de “identificación” permite a las Ciencias Sociales, más que el de “identidad étnica”, analizar los procesos mediante los cuales las personas se autoidentifican e identifican a otros. A través del estudio de las redes personales de jóvenes en Sarajevo (Bosnia y Herzegovina) se muestran diferentes procesos de identificación en un contexto de fuerte exclusión étnica. La visualización de las redes personales por parte de los propios informantes constituye una fuente privilegiada de i...

  13. O TEXTO DAS REDES SOCIAIS VIRTUAIS: MARCAS INTERACIONAIS E PROCESSUAIS

    Directory of Open Access Journals (Sweden)

    Marlete Sandra Diedrich

    2012-01-01

    Full Text Available O propósito deste texto é, na perspectiva epistemológica da Análise da Conversação, discutir o caráter interacional e processual do texto produzido nas redes sociais virtuais. As redes sociais virtuais representam, portanto, gêneros textuais produzidos por um sujeito que tem como meio de produção a escrita, mas que procura usar estruturas linguísticas que simulem, neste uso, a língua em sua modalidade falada, numa clara tentativa de intensificar o processo interacional com os demais sujeitos envolvidos no ato enunciativo.

  14. Neurons other than motor neurons in motor neuron disease.

    Science.gov (United States)

    Ruffoli, Riccardo; Biagioni, Francesca; Busceti, Carla L; Gaglione, Anderson; Ryskalin, Larisa; Gambardella, Stefano; Frati, Alessandro; Fornai, Francesco

    2017-11-01

    Amyotrophic lateral sclerosis (ALS) is typically defined by a loss of motor neurons in the central nervous system. Accordingly, morphological analysis for decades considered motor neurons (in the cortex, brainstem and spinal cord) as the neuronal population selectively involved in ALS. Similarly, this was considered the pathological marker to score disease severity ex vivo both in patients and experimental models. However, the concept of non-autonomous motor neuron death was used recently to indicate the need for additional cell types to produce motor neuron death in ALS. This means that motor neuron loss occurs only when they are connected with other cell types. This concept originally emphasized the need for resident glia as well as non-resident inflammatory cells. Nowadays, the additional role of neurons other than motor neurons emerged in the scenario to induce non-autonomous motor neuron death. In fact, in ALS neurons diverse from motor neurons are involved. These cells play multiple roles in ALS: (i) they participate in the chain of events to produce motor neuron loss; (ii) they may even degenerate more than and before motor neurons. In the present manuscript evidence about multi-neuronal involvement in ALS patients and experimental models is discussed. Specific sub-classes of neurons in the whole spinal cord are reported either to degenerate or to trigger neuronal degeneration, thus portraying ALS as a whole spinal cord disorder rather than a disease affecting motor neurons solely. This is associated with a novel concept in motor neuron disease which recruits abnormal mechanisms of cell to cell communication.

  15. Integrated neuron circuit for implementing neuromorphic system with synaptic device

    Science.gov (United States)

    Lee, Jeong-Jun; Park, Jungjin; Kwon, Min-Woo; Hwang, Sungmin; Kim, Hyungjin; Park, Byung-Gook

    2018-02-01

    In this paper, we propose and fabricate Integrate & Fire neuron circuit for implementing neuromorphic system. Overall operation of the circuit is verified by measuring discrete devices and the output characteristics of the circuit. Since the neuron circuit shows asymmetric output characteristic that can drive synaptic device with Spike-Timing-Dependent-Plasticity (STDP) characteristic, the autonomous weight update process is also verified by connecting the synaptic device and the neuron circuit. The timing difference of the pre-neuron and the post-neuron induce autonomous weight change of the synaptic device. Unlike 2-terminal devices, which is frequently used to implement neuromorphic system, proposed scheme of the system enables autonomous weight update and simple configuration by using 4-terminal synapse device and appropriate neuron circuit. Weight update process in the multi-layer neuron-synapse connection ensures implementation of the hardware-based artificial intelligence, based on Spiking-Neural- Network (SNN).

  16. HYBRID ARTIFICIAL NEURAL NETWORK APPLIEDTO MODELING SCFE OF BASIL AND ROSEMARY OILS

    Directory of Open Access Journals (Sweden)

    Giane STUART

    1997-12-01

    Full Text Available This work presents the results of a Hybrid Neural Network (HNN technique as applied to modeling SCFE curves obtained from two Brazilian vegetable matrices. A series Hybrid Neural Network was employed to estimate the parameters of the phenomenological model. A small set of SCFE data of each vegetable was used to generate an extended data set, sufficient to train the network. Afterwards, other sets of experimental data, not used in the network training, were used to validate the present approach. The series HNN correlates well the experimental data and it is shown that the predictions accomplished with this technique may be promising for SCFE purposes.Neste trabalho são apresentados os resultados obtidos na modelagem da extração supercrítica de óleo essencial de alfavaca e alecrim usando uma rede híbrida neuronal. Utilizou-se uma rede híbrida na configuração em série para estimar os parâmetros do modelo fenomenológico empregado para descrever o processo de extração, o modelo de Sovová. Um pequeno conjunto de dados experimentais, para cada matriz vegetal, foi usado para gerar um conjunto estendido de dados, suficiente para a etapa de treinamento da rede. A validação da presente proposta foi efetuada através da comparação entre os resultados preditos e aqueles obtidos experimentalmente que não constaram do processo de treinamento da rede. Demonstra-se que a rede híbrida neuronal correlaciona e prediz satisfatoriamente os dados experimentais, mostrando-se portanto promissora no campo da modelagem do processo de extração supercrítica.

  17. Modeling by artificial neural networks. Application to the management of fuel in a nuclear power plant; Modelisation par reseaux de neurones. Application a la gestion du combustible dans un reacteur

    Energy Technology Data Exchange (ETDEWEB)

    Gaudier, F

    1999-07-01

    The determination of the family of optimum core loading patterns for Pressurized Water Reactors (PWRs) involves the assessment of the core attributes, such as the power peaking factor for thousands of candidate loading patterns. Despite the rapid advances in computer architecture, the direct calculation of these attributes by a neutronic code needs a lot of of time and memory. With the goal of reducing the calculation time and optimizing the loading pattern, we propose in this thesis a method based on ideas of neural and statistical learning to provide a feed forward neural network capable of calculating the power peaking corresponding to an eighth core PWR. We use statistical methods to deduct judicious inputs (reduction of the input space dimension) and neural methods to train the model (learning capabilities). Indeed, on one hand, a principal component analysis allows us to characterize more efficiently the fuel assemblies (neural model inputs) and the other hand, the introduction of the a priori knowledge allows us to reducing the number of freedom parameters in the neural network. The model was built using a multi layered perceptron trained with the standard back propagation algorithm. We introduced our neural network in the automatic optimization code FORMOSA, and on EDF real problems we showed an important saving in time. Finally, we propose an hybrid method which combining the best characteristics of the linear local approximator GPT (Generalized Perturbation Theory) and the artificial neural network. (author)

  18. El papel de las redes sociales en la salud

    OpenAIRE

    Toledo Agua, María José; Cerezo Luque, Montserrat

    2017-01-01

    Cartel presentado en el 3er Congreso Internacional de Comunicación en Salud (3ICHC), celebrado los días 19 y 20 de octubre de 2017 en la Universidad Carlos III de Madrid. El objetivo principal de este trabajo es analizar y describir el uso de las redes sociales, y analizar sus pros y sus contras en la sanidad.

  19. Impacto de las redes sociales sobre la salud

    OpenAIRE

    Roldán Roldán, Raquel; Aranda Aranda, Federico Manuel; González Castillo, Silvia

    2017-01-01

    Cartel presentado en el 3er Congreso Internacional de Comunicación en Salud (3ICHC), celebrado los días 19 y 20 de octubre de 2017 en la Universidad Carlos III de Madrid. El objetivo de este trabajo es analizar si existe una influencia de las redes sociales sobre la población en temas relacionados con su salud.

  20. Tema 5. Comunicaciones y redes. Transparencias. Curso 2012-2013

    OpenAIRE

    Saiz Noeda, Maximiliano

    2012-01-01

    TEMA 5. COMUNICACIONES Y REDES. TRANSPARENCIAS. Este tema hace un recorrido por las tecnologías de comunicación entre sistemas electrónicos, los dispositivos y medios de comunicación más comunes, así como Internet como el recurso fundamental de comunicación en nuestra era.

  1. Tema 5. Comunicaciones y Redes. Transparencias. Curso 2010-2011

    OpenAIRE

    Saiz Noeda, Maximiliano

    2010-01-01

    TEMA 5. COMUNICACIONES Y REDES. TRANSPARENCIAS. Este tema hace un recorrido por las tecnologías de comunicación entre sistemas electrónicos, los dispositivos y medios de comunicación más comunes, así como Internet como el recurso fundamental de comunicación en nuestra era.

  2. Tema 5. Comunicaciones y Redes. Transparencias. Curso 2011-2012

    OpenAIRE

    Saiz Noeda, Maximiliano

    2011-01-01

    TEMA 5. COMUNICACIONES Y REDES. TRANSPARENCIAS. Este tema hace un recorrido por las tecnologías de comunicación entre sistemas electrónicos, los dispositivos y medios de comunicación más comunes, así como Internet como el recurso fundamental de comunicación en nuestra era.

  3. Redes sociales: herramienta de marketing internacional en el sector hotelero

    Directory of Open Access Journals (Sweden)

    Ana María Miranda Zavala

    2016-01-01

    Full Text Available El presente artículo tiene como objetivo identificar las estrategias de marketing internacional en redes sociales que realizan los hoteles de cuatro y cinco estrellas de la ciudad de Tijuana, Baja California, México. Así mismo, la revisión de las características y contenidos de las redes sociales de este sector, reconociendo la importancia en el marketing internacional como medio de comunicación con los huéspedes. De este modo, se propone caracterizar los atributos que consideran esenciales los huéspedes de los hoteles y que hacen que el visitante incremente su confianza en la utilización de dichos medios. La investigación ha contemplado un análisis cualitativo de las redes sociales de 16 hoteles registrados en la Secretaría de Turismo (SECTUR y la Asociación de Hoteles del Noroeste (ASHONO para identificar la manera en que llevan a cabo su estrategia de marketing a través de esos medios. Asimismo, se aplicaron encuestas a 267 huéspedes de los hoteles con la finalidad de identificar los atributos que consideran importantes que aparezcan en la red social del hotel, que habrían de incrementar la eficiencia de los resultados de la estrategia de marketing con redes sociales.

  4. A neuron-astrocyte transistor-like model for neuromorphic dressed neurons.

    Science.gov (United States)

    Valenza, G; Pioggia, G; Armato, A; Ferro, M; Scilingo, E P; De Rossi, D

    2011-09-01

    Experimental evidences on the role of the synaptic glia as an active partner together with the bold synapse in neuronal signaling and dynamics of neural tissue strongly suggest to investigate on a more realistic neuron-glia model for better understanding human brain processing. Among the glial cells, the astrocytes play a crucial role in the tripartite synapsis, i.e. the dressed neuron. A well-known two-way astrocyte-neuron interaction can be found in the literature, completely revising the purely supportive role for the glia. The aim of this study is to provide a computationally efficient model for neuron-glia interaction. The neuron-glia interactions were simulated by implementing the Li-Rinzel model for an astrocyte and the Izhikevich model for a neuron. Assuming the dressed neuron dynamics similar to the nonlinear input-output characteristics of a bipolar junction transistor, we derived our computationally efficient model. This model may represent the fundamental computational unit for the development of real-time artificial neuron-glia networks opening new perspectives in pattern recognition systems and in brain neurophysiology. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Integrando Redes Sociales y Técnicas de Inteligencia Artificial en Entornos Educativos

    OpenAIRE

    Antonieta Kuz; Mariana Falco; Leopoldo Nahuel; Roxana Giandini

    2015-01-01

    In this research we explored a methodological proposal whose main purpose is to show and clarify the use of Information Technology and Communication in teacher education, using Conversational Software Agents and Social Network Analysis. In this context, the real-time work with the teacher is emphasized, and is feasible therefore to generate a practical and useful software tool, called Agent SocialMetric.

  6. Integrando Redes Sociales y Técnicas de Inteligencia Artificial en Entornos Educativos

    Directory of Open Access Journals (Sweden)

    Antonieta Kuz

    2015-07-01

    Full Text Available In this research we explored a methodological proposal whose main purpose is to show and clarify the use of Information Technology and Communication in teacher education, using Conversational Software Agents and Social Network Analysis. In this context, the real-time work with the teacher is emphasized, and is feasible therefore to generate a practical and useful software tool, called Agent SocialMetric.

  7. Predição de séries financeiras utilizando wavelets e redes neurais: ummodelo para os fundos de investimentos imobiliários

    Directory of Open Access Journals (Sweden)

    Fabrício Soares

    2014-08-01

    Full Text Available Este artigo apresenta o desenvolvimento de um modelo de predição de séries temporais financeiras com o uso da Rede Neural Artificial TLFN Distribuída (Time Lagged FeedForward Network - Rede Neural Alimentada para frente Atrasada no Tempo, treinada com o algoritmo backpropagation temporal e com o pré-processamento dos sinais de entrada realizado com as Transformadas Wavelets Discretas. A metodologia demonstra como a análise de multirresolução feita com o algoritmo piramidal de Mallat colaborou para o aumento da capacidade de generalização da rede neural, otimizando as previsões feitas pelo modelo implementado. Com a finalidade de demonstrar a eficácia desta metodologia, foi realizado um estudo de caso envolvendo a séries histórica de cotações das cotas, negociadas no mercado secundário, do Fundo de Investimento Imobiliário Almirante Barroso.

  8. Diseño de un sistema multi-agente para monitoreo de redes utilizando JADE y JPCAP

    Directory of Open Access Journals (Sweden)

    Alexis De la Hoz Manotas

    2010-01-01

    Full Text Available La programación orientada a agentes es un paradigma que ha tomado especial dedicación en los últimos años, en especial en investigaciones, desde sistemas de supervisión y control de redes de computadores, simulación de procesos industriales, recopilación de información, sistemas de oferta y demanda, etc. El diseño de un sistema multiagente (MAS requiere esfuerzos diferentes a los encontrados en un desarrollo de software tradicional, diversas estrategias como BDI, GAIA y MESSAGE pueden ser utilizadas como modelo teórico para tal fin, mas sin embargo, con los avances en la inteligencia artificial, los agentes inteligentes están ahora en capacidad de demostrar mucha mayor autonomía y aprendizaje que hasta ahora. Se ha desarrollado un primer intento en esbozar lo que sería el diseño de un sistema multiagente para la monitorización de redes, escogiendo como plataforma de desarrollo a JADE y Jpcap como herramientas de captura.

  9. Estimación de la resistencia a la penetración de suelos usando redes neuronales artificiales

    Directory of Open Access Journals (Sweden)

    Nidia Johana Valdés Holguín

    2011-07-01

    Full Text Available Las redes neuronales artificiales, simuladoras del proceso de aprendizaje de las neuronas biológicas, han sido utilizadas con éxito en el cálculo de parámetros en diversos problemas de ingeniería en que las variables involucradas tienen una alta relación no lineal entre sí y la modelación no permite representar el problema mediante una función matemática de fácil deducción. En la ciencia del suelo la predicción de algunas propiedades involucra diversas variables que hacen de su estimación por medio de modelos matemáticos un proceso complejo, y trasladan la solución del problema al campo de la inteligencia artificial. En el presente artículo se reporta la elaboración de redes neuronales artificiales para la estimación de la resistencia a la penetración a diferentes profundidades de un suelo; se consideran como variables influyentes el contenido de humedad, la densidad, la carga estática y la presión de inflado. Los resultados muestran una mejor estimación para profundidades entre 20 cm y 30 cm.

  10. 7 lecturas para iniciarse en el análisis de redes sociales. Una selección de REDES

    Directory of Open Access Journals (Sweden)

    Jorge Enrique Palacio Sañudo

    2014-06-01

    Full Text Available En esta publicación, tenemos la oportunidad de leer en un solo documento varios artículos clásicos o de gran relevancia científica sobre las redes sociales, los cuales han sido traducidos al español en texto completo, y se han publicado en la Revista REDES en diferentes números. La claridad y calidad de estos artículos es esencial para comprender los fundamentos teóricos de muchos estudios sociales que nos permiten entender nuestra sociedad desde un punto de vista estructural. Este libro es un recurso de utilidad en contextos formativos, como material complementario en los cursos de introducción al análisis de redes sociales. Puede ser de interés para los estudiantes de grado y postgrado que se estén familiarizando con las redes sociales. A continuación revisamos el detalle de cada capítulo.

  11. Redes Neuronales y su aplicación predictiva en la Bolsa de Valores española

    Directory of Open Access Journals (Sweden)

    Ibarra Alfaraz, J.A.

    1999-01-01

    Full Text Available Este trabajo recoge una visión general de las redes neuronales y su tendencia en la investigación actual. Además de las aplicaciones conocidas donde las redes neuronales han demostrado su aplicabilidad se abren nuevos campos de investigación. En nuestro caso, nos centraremos en el área económica y más concretamente en la financiera. Esta metodología se aplica al caso concreto del análisis predictivo de la bolsa de valores, concretamente se utiliza el índice del mercado continuo de la bolsa española, Ibex-35, y los recientemente aparecidos índices sectoriales del Ibex: Servicios, Financiero, Utilities y Complementario. La red neuronal utilizada, Perceptron, ha sido entrenada con los datos reales procedentes de la bolsa de valores utilizando diferentes periodos de tiempo y efectuando cambios en los parámetros que condicionan la capacidad predictiva de la red. Los resultado se han contrastado con los obtenidos en otros trabajos empíricos realizados con metodologías clásicas.

  12. Artificial Hydration and Nutrition

    Science.gov (United States)

    ... Crisis Situations Pets and Animals myhealthfinder Food and Nutrition Healthy Food Choices Weight Loss and Diet Plans ... Your Health Resources Healthcare Management Artificial Hydration and Nutrition Artificial Hydration and Nutrition Share Print Patients who ...

  13. Artificial Disc Replacement

    Science.gov (United States)

    ... Spondylolisthesis BLOG FIND A SPECIALIST Treatments Artificial Disc Replacement (ADR) Patient Education Committee Jamie Baisden The disc ... Disc An artificial disc (also called a disc replacement, disc prosthesis or spine arthroplasty device) is a ...

  14. Application of artificial intelligence to the management of urological cancer.

    Science.gov (United States)

    Abbod, Maysam F; Catto, James W F; Linkens, Derek A; Hamdy, Freddie C

    2007-10-01

    Artificial intelligence techniques, such as artificial neural networks, Bayesian belief networks and neuro-fuzzy modeling systems, are complex mathematical models based on the human neuronal structure and thinking. Such tools are capable of generating data driven models of biological systems without making assumptions based on statistical distributions. A large amount of study has been reported of the use of artificial intelligence in urology. We reviewed the basic concepts behind artificial intelligence techniques and explored the applications of this new dynamic technology in various aspects of urological cancer management. A detailed and systematic review of the literature was performed using the MEDLINE and Inspec databases to discover reports using artificial intelligence in urological cancer. The characteristics of machine learning and their implementation were described and reports of artificial intelligence use in urological cancer were reviewed. While most researchers in this field were found to focus on artificial neural networks to improve the diagnosis, staging and prognostic prediction of urological cancers, some groups are exploring other techniques, such as expert systems and neuro-fuzzy modeling systems. Compared to traditional regression statistics artificial intelligence methods appear to be accurate and more explorative for analyzing large data cohorts. Furthermore, they allow individualized prediction of disease behavior. Each artificial intelligence method has characteristics that make it suitable for different tasks. The lack of transparency of artificial neural networks hinders global scientific community acceptance of this method but this can be overcome by neuro-fuzzy modeling systems.

  15. Spin orbit torque based electronic neuron

    Energy Technology Data Exchange (ETDEWEB)

    Sengupta, Abhronil, E-mail: asengup@purdue.edu; Choday, Sri Harsha; Kim, Yusung; Roy, Kaushik [School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)

    2015-04-06

    A device based on current-induced spin-orbit torque (SOT) that functions as an electronic neuron is proposed in this work. The SOT device implements an artificial neuron's thresholding (transfer) function. In the first step of a two-step switching scheme, a charge current places the magnetization of a nano-magnet along the hard-axis, i.e., an unstable point for the magnet. In the second step, the SOT device (neuron) receives a current (from the synapses) which moves the magnetization from the unstable point to one of the two stable states. The polarity of the synaptic current encodes the excitatory and inhibitory nature of the neuron input and determines the final orientation of the magnetization. A resistive crossbar array, functioning as synapses, generates a bipolar current that is a weighted sum of the inputs. The simulation of a two layer feed-forward artificial neural network based on the SOT electronic neuron shows that it consumes ∼3× lower power than a 45 nm digital CMOS implementation, while reaching ∼80% accuracy in the classification of 100 images of handwritten digits from the MNIST dataset.

  16. Spin orbit torque based electronic neuron

    International Nuclear Information System (INIS)

    Sengupta, Abhronil; Choday, Sri Harsha; Kim, Yusung; Roy, Kaushik

    2015-01-01

    A device based on current-induced spin-orbit torque (SOT) that functions as an electronic neuron is proposed in this work. The SOT device implements an artificial neuron's thresholding (transfer) function. In the first step of a two-step switching scheme, a charge current places the magnetization of a nano-magnet along the hard-axis, i.e., an unstable point for the magnet. In the second step, the SOT device (neuron) receives a current (from the synapses) which moves the magnetization from the unstable point to one of the two stable states. The polarity of the synaptic current encodes the excitatory and inhibitory nature of the neuron input and determines the final orientation of the magnetization. A resistive crossbar array, functioning as synapses, generates a bipolar current that is a weighted sum of the inputs. The simulation of a two layer feed-forward artificial neural network based on the SOT electronic neuron shows that it consumes ∼3× lower power than a 45 nm digital CMOS implementation, while reaching ∼80% accuracy in the classification of 100 images of handwritten digits from the MNIST dataset

  17. Artificial life and Piaget.

    Science.gov (United States)

    Mueller, Ulrich; Grobman, K H.

    2003-04-01

    Artificial life provides important theoretical and methodological tools for the investigation of Piaget's developmental theory. This new method uses artificial neural networks to simulate living phenomena in a computer. A recent study by Parisi and Schlesinger suggests that artificial life might reinvigorate the Piagetian framework. We contrast artificial life with traditional cognitivist approaches, discuss the role of innateness in development, and examine the relation between physiological and psychological explanations of intelligent behaviour.

  18. Redes sociales y mujeres mayores: estudio sobre la influencia de las redes sociales en la calidad de vida

    Directory of Open Access Journals (Sweden)

    María Fernández Campomanes

    2014-06-01

    Full Text Available Este artículo trata de avanzar en el conocimiento de la situación de las mujeres mayores respecto al uso de las redes sociales y su relación con la calidad de vida. Se ocupa de un colectivo al que nuestra sociedad no presta demasiada atención desde una perspectiva política ni académica y lo hace desde un punto de vista de absoluta vigencia, como es la participación en las redes sociales. El marco teórico lo trazan la revisión de las ideas de web 2.0, brecha digital y brecha digital de género, y envejecimiento activo y calidad de vida. Es un trabajo cualitativo para el que se ha realizado un muestreo de carácter intencional de ocho casos típicos que responden al perfil de mujeres de más de 55 años, residentes en Asturias, cuidadoras y usuarias de las redes sociales, cuya vinculación con las TIC no está relacionada con el empleo ni con su trayectoria académica. Se han llevado a cabo cinco entrevistas en profundidad y un grupo de discusión heterogéneo formado por tres usuarias y tres expertas en materia de igualdad y nuevas tecnologías. Analizados los datos a la luz de las categorías establecidas, el estudio concluye que el acceso a internet y a las redes sociales influye en la mejora de la calidad de vida de las mujeres mayores y los resultados que se alcanzan contribuyen a perfilar ideas de gran relevancia para formular políticas públicas que fomenten la igualdad en el acceso de las mujeres mayores a las redes sociales.

  19. Uso de redes neuronales artificiales para mejorar el tránsito en las vías

    Directory of Open Access Journals (Sweden)

    Edwin Mejía

    2016-11-01

    Full Text Available Este artículo pretende dar una idea de cómo las Redes Neuronales Artificiales (ANNs, una técnica de la Inteligencia Artificial (IA, se puede acoplar a resolver el problema del tráfico en las vías de la ciudad de Riobamba, provincia de Chimborazo, país Ecuador, usando cuatro semáforos estándar, a través de un ejemplo se indica el uso de componentes electrónicos como FPGAs (Field Programmable Gate array y los sensores en este campo, a través de detectar y contar autos puede dar mayor fluidez al tráfico. La vía que mayor cantidad de autos tenga se dará mayor prioridad para la luz verde. Usando el algoritmo de aprendizaje de un Perceptrón Simple.

  20. Pronóstico de los índices accionarios DAX y S&P 500 con redes neuronales diferenciales

    Directory of Open Access Journals (Sweden)

    Francisco Ortiz Arango

    2013-01-01

    Full Text Available En este trabajo se utiliza una red neuronal diferencial (RND para describir las series de valores de cierre diarios de los índices accionarios DAX de Alemania y S&P 500 de Estados Unidos entre el periodo del 3 de julio de 2000 y el 13 de enero de 2012. Con la RND se lleva a cabo el pronóstico de los valores de cierre diarios de esos índices durante un periodo de cuatro semanas (del 16 de enero al 10 de febrero de 2012. Los resultados obtenidos confirman el hecho de que las redes neuronales diferenciales pueden constituirse en una de las herramientas más poderosas y precisas para poder pronosticar valores futuros de activos financieros.

  1. Study of the thermo-mechanical behavior of medium carbon microalloyed steel during hot forming process using an artificial neural network; Estudio del comportamiento termo-mecanico de un acero microaleado de medio carbono durante un proceso de conformado en caliente usando una red neuronal artificial

    Energy Technology Data Exchange (ETDEWEB)

    Alcelay, I.; Pena, E.; Al Omar, A.

    2016-10-01

    The thermo-mechanical behavior of medium carbon microalloyed steel has been analyzed by an Artificial Neural Network (ANN). The flow curves for training the ANN have been obtained from the hot compression tests, carried out over a temperature range varying from 900 to 1150 degree centigrade and at different true strain rates ranging from 10{sup -}4 to 10 s{sup -}1. It has been found that the ANN model developed in this study is capable to predict accurately and efficiently the flow behavior of the studied steel and there is a good agreement between the experimental results and the ANN results. To analyze the formability of the studied steel, processing maps have been constructed on the basis of the Dynamic Materials Model (DMM), using the ANN values of the flow stress. The study of maps reveals the different domains of the flow behavior of the studied steel and shows the great similarity between the experimental results and the theoretical results, so the use of the ANN can constitute an interesting alternative for design and study of hot forming processes. (Author)

  2. Redes de conocimiento vivo e hiper información

    Directory of Open Access Journals (Sweden)

    Carlos Cortés Amador

    1993-07-01

    Full Text Available Este artículo se inicia con una descripción sobre medios de comunicación y la transmisión de imágenes, con sus implicaciones en los sistemas y redes de comunicación. Antes de reseñar la economía de servicios, se tratan los mercados de conocimientos; lo anterior sirve de preludio para entrar en las redes sociales vivas de conocimiento. Como puntos técnicos centrales del artículo se describen brevemente dos conceptos. El primero es el de sistemas expertos y el segundo es el de hiperinformación. Finalmente se concluye que dentro de la cultura institucional, es recurso estratégico el conocimiento, cuyos contenidos deben ser difundidos mediante la aplicación de la hiperinformación.

  3. REDES DO COMÉRCIO DE RUA DE SALVADOR, BAHIA

    Directory of Open Access Journals (Sweden)

    Ana Cláudia Nogueira Maia

    2015-01-01

    Full Text Available Este trabajo representa un estudio de caso de comercio de la calle que se produce en la Centralización Iguatemi y Avenida Lima e Silva, en Salvador, Bahia. Al caminar por las calles es la diversidad notable que esta actividad presenta son bienes de todo tipo, ropa, electrónica, productos alimenticios y los que están diseñados para satisfacer una necesidad momentánea. Buscamos entender el camino que lleva a la diversidad bienes desde la producción hasta el consumo, se analizan los productos de “extranjero” en un intento de controlar todo el trayecto del camino para ellos. Por lo tanto, desarrollamos un entendimiento en torno a redes posibles formados detrás de la venta ambulante, es decir, las redes de suministro de este comercio.

  4. Building functional networks of spiking model neurons.

    Science.gov (United States)

    Abbott, L F; DePasquale, Brian; Memmesheimer, Raoul-Martin

    2016-03-01

    Most of the networks used by computer scientists and many of those studied by modelers in neuroscience represent unit activities as continuous variables. Neurons, however, communicate primarily through discontinuous spiking. We review methods for transferring our ability to construct interesting networks that perform relevant tasks from the artificial continuous domain to more realistic spiking network models. These methods raise a number of issues that warrant further theoretical and experimental study.

  5. Predicción de la demanda eléctrica horaria mediante redes neuronales artificiales.

    Directory of Open Access Journals (Sweden)

    Mallo González, Carlos

    2004-01-01

    Full Text Available En este trabajo se realiza una introducción a los modelos neuronales y se explora su aplicabilidad en el terreno de la economía cuantitativa como instrumento de modelización y predicción no paramétrica. A tal objeto hemos desarrollado un modelo de Red Neuronal Artificial que posteriormente aplicaríamos en la predicción de la demanda horaria de energía eléctrica con datos reales. Los resultados así obtenidos con los ofrecidos por las metodologías convencionales de ajuste y predicción

  6. RESSIGNIFICAÇÕES DO ACONTECIMENTO NO JORNALISMO EM REDE

    Directory of Open Access Journals (Sweden)

    Gabriela da Silva Zago

    2017-05-01

    Full Text Available O trabalho procura abordar as possíveis ressignificações do acontecimento no jornalismo em rede. Para tanto, tweets sobre acontecimentos relacionados à Copa do Mundo de 2014 são utilizados como recorte, em caráter ilustrativo. Resultados apontam para um papel ativo de participação dos usuários na circulação de conteúdos, atuando não apenas no espalhamento da informação, como também atribuindo novos sentidos aos acontecimentos que, ao recircularem, são reconstruídos.   PALAVRAS-CHAVE: jornalismo em rede; acontecimento; redes sociais     ABSTRACT This paper aims to address the possible resignifications of news events on network journalism. To do so, we use tweets about events related to the 2014 FIFA World Cup for illustrative purposes. Our results point to an active role of participation of users on news circulation, acting not only by spreading information, but also by attributing new meanings to the events, which, by being put into recirculation, are reconstructed.   KEYWORDS: network journalism; news events; social networks     RESUMEN Este trabajo trata de abordar la posible reinterpretación del acontecimiento en el periodismo en red. Para eso, se utiliza de tweets sobre acontecimientos relacionados a la Copa del Mundo de 2014, con fines ilustrativos. Los resultados apuntan a un papel activo de la participación de usuario en la circulación de contenidos, actuando no sólo en la difusión de la información, como también en la asignación de nuevos significados a acontecimientos, que, cuando recirculam, se reconstruyen.   PALABRAS-CLAVE: periodismo en red; acontecimiento; redes sociales.

  7. Redes sociales : la memoria de la Historia en tiempo real

    OpenAIRE

    Argila Blanco, Judith

    2015-01-01

    Novedosos estudios muestran cómo a través de técnicas combinadas de análisis de redes y de minería de datos (especialmente en Twitter, que ofrece datos abiertos) es posible identificar climas de opinión dentro de colectivos de individuos inmersos en procesos históricos contemporáneos

  8. Redes sociales: La memoria de la Historia en tiempo real

    OpenAIRE

    Argila Blanco, Judith

    2015-01-01

    Novedosos estudios muestran cómo a través de técnicas combinadas de análisis de redes y de minería de datos (especialmente en Twitter, que ofrece datos abiertos) es posible identificar climas de opinión dentro de colectivos de individuos inmersos en procesos históricos contemporáneos.

  9. Juventud y redes sociales: Motivaciones y usos preferentes

    Directory of Open Access Journals (Sweden)

    Pilar Colás Bravo

    2013-03-01

    Full Text Available Este artículo presenta los resultados de un estudio sobre la utilización que hacen los jóvenes andaluces de las redes sociales. Los objetivos fundamentales son: conocer los usos preferentes de las redes sociales, su frecuencia y los motivos que les impulsan a su utilización. Además se estudia si existen diferencias de sexo tanto en la frecuencia como en las motivaciones de uso. Se aplica un cuestionario para la recogida de datos. La muestra es de 1.487 adolescentes de Andalucía. Los resultados muestran que los jóvenes en su mayoría usan de manera habitual las redes sociales y se identifican dos vertientes motivacionales en su uso: una social y otra psicológica. No se hallan diferencias significativas entre sexos en cuanto a frecuencia de uso, pero sí en las motivaciones para su acceso. Las de los chicos son de tipo emocional, mientras que en las chicas predomina la motivación de carácter relacional. Los resultados obtenidos muestran coincidencias con investigaciones internacionales realizadas en contextos muy diferentes al presente estudio. En la discusión de resultados se plantean futuras líneas de trabajo, a la vez que se identifican implicaciones que los usos de las redes sociales tienen para la formación e integración social de una ciudadanía activa y participativa, así como para el enriquecimiento de dimensiones como el desarrollo del capital social y la educación.

  10. Geothermics and neural networks: A first approach; Geotermia y redes neuronales: Una primera aproximacion

    Energy Technology Data Exchange (ETDEWEB)

    Flores Armenta, Magaly del Carmen [Gerencia de Proyectos Geotermoelectricos de la Comision Federal de Electricidad, Morelia (Mexico); Barragan Orbe, Carlos [Comision Federal de Electricidad, Mexico, D. F. (Mexico)

    1995-09-01

    Neural networks have been hailed as the greatest technological advance since the transistor. They are predicted to be a common household item by the year 2000. This new form of machine intelligence is able to solve problems, without using rules of math, they only need examples to learn from. The first geothermal problem, to solve with this powerful tool, is the prediction of liquid and steam production, as well as the well`s termination in Los Humeros, Puebla, Mexico. The first attempt shows the learning`s capacity of the developed model, and its precision on the predictions that were done. [Espanol] Las redes neuronales se consideran como uno de los mas grandes avances tecnologicos desde la invencion del transistor, de tal forma que se perfilan como una de las herramientas mas comunes del ano 2000. Esta nueva forma de inteligencia artificial es capaz de resolver problemas sin utilizar reglas matematicas, solamente requiere de ejemplos para aprender de ellos. El primer problema geotermico, atacado con esta poderosa herramienta, es la prediccion de las producciones de vapor y liquido, asi como la terminacion de pozos en el campo geotermico de Los Humeros, Puebla, Mexico. Los primeros intentos demuestran la capacidad de aprender del modelo desarrollado, y su certeza en las predicciones realizadas.

  11. Redes sociales aplicadas a la educación: EDMODO

    Directory of Open Access Journals (Sweden)

    Santiago Alonso-García

    2015-07-01

    Full Text Available El artículo que a continuación abordamos, versa sobre un proyecto de innovación educativa que trata de incorporar las Redes Sociales a la educación analizando su valor didáctico. Esto se realiza a través del aprendizaje y posterior uso de una plataforma educativa llamada EDMODO. Abordaremos el tema del aprendizaje mixto o blended learning, facilitando su concepto y las ventajas que esta metodología aporta al proceso de enseñanza-aprendizaje. Finalizaremos este primer apartado analizando de manera global el concepto de comunidades virtuales y las ventajas que éstas proporcionan a la práctica docente. De forma más detallada, nos centraremos en una de estas comunidades virtuales, llamada EDMODO, en la cual se centra nuestro proyecto de innovación. Una vez examinado el marco teórico de este proyecto, pasaremos a tratar los objetivos, la metodología y la aplicación del mismo. Llegados a este punto, tendremos la información necesaria para analizar los resultados positivos obtenidos y extraer las conclusiones oportunas sobre la necesidad de aplicación de las redes sociales en contextos educativos, concretamente EDMODO. Para terminar este proyecto, analizaremos las futuras líneas de implantación de estas redes sociales en los centros educativos y su futura viabilidad.

  12. EL NUEVO PARADIGMA EMPRESARIAL: El Esquema de Redes

    Directory of Open Access Journals (Sweden)

    Ignasi Brunet Icart

    2004-07-01

    Full Text Available Hoy las organizaciones están cambiando drásticamente y adoptando nuevas formas de operación. Detrás de este fenómeno hay un compromiso con el rendimiento y con la creación de valores, que ha alterado profundamente la economía y la vida cotidiana. El principio de creación de valor estimula la tendencia de reemplazar la actual organización piramidal por un esquema de redes. El problema de fondo es cómo optimizar los recursos disponibles, y ello puede lograrse mediante un nuevo paradigma gerencial con redes de firmas interrelacionadas que maximizan la coordinación, la obtención de economías de escala y la explotación de sinergias. El objetivo de este artículo es describir este paradigma emergente que impone contar con estructuras flexibles que permitan la readaptación de las organizaciones. Por otra parte, la conclusión a que llegamos es que la generalización de los esquemas de redes explica que las sociedades avanzadas se articulan, cada vez más, en base a una lógica conexionista.

  13. Las redes sociales directivas externas y la estrategia corporativa

    Directory of Open Access Journals (Sweden)

    Fernández Pérez, Virginia

    2008-11-01

    Full Text Available Este trabajo pretende aportar un punto de vista más amplio sobre el desarrollo de la toma de decisiones directiva relacionada con la elección e implantación de la estrategia corporativa, para lo que incorpora las redes sociales externas de los directivos como elemento explicativo del proceso, ya que son fuentes de información y referencias sociales muy importantes. Los contactos sociales pueden condicionar en gran medida el comportamiento estratégico de la organización y por tanto, su desempeño. En particular, se han estudiado varias de las dimensiones de la estructura de dichas redes para profundizar en sus efectos. Estas dimensiones son el tamaño y la fortaleza y tienen diferente incidencia sobre las distintas etapas del proceso de toma de decisiones, siendo más importante el tamaño para la captación de información y oportunidades de negocio, dando lugar a comportamientos emprendedores y estrategias proactivas; mientras que la fortaleza suele estar relacionada con estrategias más conservadoras. Y todo ello nos deja entrever la importancia de las redes sociales directivas en general y como una adecuada estructura puede ser determinante para el éxito empresarial.

  14. Comunidades virtuais gerando identidades na sociedade em rede

    Directory of Open Access Journals (Sweden)

    Cynthia Harumy Watanabe Corrêa

    2011-01-01

    Full Text Available

    A revolução tecnológica concentrada nas Tecnologias da Informação e da Comunicação (TICs, que possibilita a conexão mundial via redes de computadores, promove alterações significativas na base material da sociedade, ao estabelecer uma interdependência global entre os países e modificar as relações entre economia, Estado-nação e sociedade.  O uso crescente de redes como a Internet resultou na criação de um novo tipo de organização social, a sociedade em rede, que permite a formação de comunidades virtuais, grupos humanos constituídos pela identificação de interesses comuns.  Neste artigo, elaborado a partir de revisão teórica, abordaremos a formação dessas comunidades como uma estratégia do indivíduo para adquirir uma nova identidade, uma vez que as identidades culturais estão se fragmentando em conseqüência do processo de globalização, que é inerente à modernidade.

  15. Sistemas únicos, centralizados e integrados para a gestão de redes de franquias

    OpenAIRE

    Kalaf, Edison Audi

    2009-01-01

    O modelo de organização empresarial em rede, particularmente redes de franquias, vem crescendo a taxas bastante superiores à média da economia. A importância do setor de franquias no Brasil como fornecedor de produtos e serviços e o seu peso social como gerador de empregos e na arrecadação de impostos tornam a administração das redes de franquias um elemento relevante dentro do cenário econômico nacional, justificando as iniciativas de aprimoramento da gestão de redes de franqu...

  16. REDES ROCIAIS: TECNOLOGIA E SOCIEDADE NA PROMOÇÃO DA SAÚDE

    OpenAIRE

    Vermelho, Sonia Cristina; UFRJ; Velho, Ana Paula Machado; UNICESUMAR/UEM

    2015-01-01

    Neste artigo apresentamos resultado de pesquisa empírica realizada em 2012-2013 sobre o tema das redes sociais online disponibilizadas para a população brasileira. O levantamento procurou mapear e criar uma tipologia em relação ao tipo de uso e público que são direcionadas as redes. A metodologia utilizada contou com a aplicação de técnicas de pesquisa bibliográfica, com análise de conteúdo. Da pesquisa, identificamos 83 redes, com predomínio para as redes abertas, voltadas predominantemente ...

  17. Redes de colaboración en Educación Superior

    OpenAIRE

    Solano Fernández, Isabel Mª

    2012-01-01

    Redes de colaboración para la Educación Superior. Se analiza el modelo pedagógico constructivista social, y dentro de este el método colaborativo. Posteriormente analiza las posibilidades de las redes, redes sociales y medios sociales, para la Educación. Presentación realizada para realizar el taller "redes de colaboración en Educación Superior" en el Seminario de innovación docente Organizado por el Centro de Desarrolo Docente (CDDOC) de la Universidad Católica de Chile.

  18. Estilos interpessoais e participação em redes sociais em diferentes ambientes de trabalho

    OpenAIRE

    Brito, Fernanda de Souza

    2012-01-01

    110f. Este estudo examinou a relação entre estilos interpessoais e a participação do indivíduo nas redes sociais em diferentes ambientes de trabalho. Redes sociais se formam pelos vínculos afetivos, cognitivos e de compartilhamento de recursos estabelecidos entre atores sociais. Diferenças de desempenho no trabalho podem estar relacionadas ao posicionamento das pessoas em suas redes sociais. Ocupar uma posição de centralidade em uma rede social possibilita a aquisição de inf...

  19. Herramientas de software de simulación para redes de comunicaciones

    OpenAIRE

    Torres, Juan Antonio

    2015-01-01

    Actualmente los sistemas de computación y redes de comunicación son parte esencial del funcionamiento de las empresas, y una de las tareas más importantes, de los diseñadores de redes. El estudio del desempeño de las redes de comunicaciones a través de la simulación es una forma de abordar estas redes de comunicaciones. Las herramientas de simulación vista son: NetSim, Jimsim, KivaNS, Network Simulator, OMNET ++, Packet Tracer, OPNET Modeler, RouterSim Network Simulators, Toggit y ...

  20. Roteamento em redes em malha sem fio com balanceamento de carga e caminhos mais curtos

    OpenAIRE

    Mello, Micael Oliveira Massula Carvalho de

    2014-01-01

    Redes em Malha Sem Fio - Wireless Mesh Networks (WMNs) são infraestruturas com propriedades autonômicas, como auto-organização e autorrecuperação, que podem ser implementadas com tecnologias amplamente disponíveis e de custo acessível. Além de suas aplicações atuais, como redes comunitárias e redes de acesso à Internet, as WMNs podem auxiliar na comunicação de Internet das Coisas e constituir infraestruturas robustas para redes inteligentes de energia, dentre outros usos. No en...

  1. An experimental biomimetic platform for artificial olfaction.

    Directory of Open Access Journals (Sweden)

    Corrado Di Natale

    Full Text Available Artificial olfactory systems have been studied for the last two decades mainly from the point of view of the features of olfactory neuron receptor fields. Other fundamental olfaction properties have only been episodically considered in artificial systems. As a result, current artificial olfactory systems are mostly intended as instruments and are of poor benefit for biologists who may need tools to model and test olfactory models. Herewith, we show how a simple experimental approach can be used to account for several phenomena observed in olfaction. An artificial epithelium is formed as a disordered distributed layer of broadly selective color indicators dispersed in a transparent polymer layer. The whole epithelium is probed with colored light, imaged with a digital camera and the olfactory response upon exposure to an odor is the change of the multispectral image. The pixels are treated as olfactory receptor neurons, whose optical properties are used to build a convergence classifier into a number of mathematically defined artificial glomeruli. A non-homogenous exposure of the test structure to the odours gives rise to a time and spatial dependence of the response of the different glomeruli strikingly similar to patterns observed in the olfactory bulb. The model seems to mimic both the formation of glomeruli, the zonal nature of olfactory epithelium, and the spatio-temporal signal patterns at the glomeruli level. This platform is able to provide a readily available test vehicle for chemists developing optical indicators for chemical sensing purposes and for biologists to test models of olfactory system organization.

  2. Applications of artificial intelligence technology to wastewater treatment fields in China

    Institute of Scientific and Technical Information of China (English)

    QING Xiao-xia; WANG Bo; MENG De-tao

    2005-01-01

    Current applications of artificial intelligence technology to wastewater treatment in China are summarized. Wastewater treatment plants use expert system mainly in the operation decision-making and fault diagnosis of system operation, use artificial neuron network for system modeling, water quality forecast and soft measure, and use fuzzy control technology for the intelligence control of wastewater treatment process. Finally, the main problems in applying artificial intelligence technology to wastewater treatment in China are analyzed.

  3. Emisión Acústica y Redes Neuronales para Modelado y Caracterización del Proceso de Soldadura por Fricción Agitación

    Directory of Open Access Journals (Sweden)

    Emilio Jiménez Macías

    2013-10-01

    Full Text Available Resumen: En esta investigación se realiza un análisis para el modelado y la caracterización de los parámetros del proceso de soldadura por fricción agitación (FSW a partir de las señales vibro-acústicas generadas por el proceso. El modelo se basa en una red neuronal empleada para predecir los parámetros del proceso de soldadura a partir de la medición on-line de las señales generadas durante su ejecución. En los ensayos se han soldado chapas de aluminio AA1050 H24 con 3 mm de espesor, y las señales del proceso de soldadura han sido adquiridas empleando un sistema de adquisición NI USB-9234. Como entradas para el modelo basado en la Red Neuronal Artificial (RNA se han empleado parámetros de caracterización de las señales a partir de la señal temporal y su descomposición a partir de la aplicación de Transformada Wavelet. Como salidas del modelo se han escogido los parámetros del proceso: velocidad de rotación, avance y diseño de la herramienta. Se ha empleado una red multicapas feed-forward, estudiándose diferentes topologías y algoritmos de entrenamiento. Los resultados obtenidos a partir de la comparación de los datos experimentales y los estimados por la RNA, demuestran la validez del modelo obtenido a partir de las investigaciones, el cual abre la puerta a avances en el control automático de los parámetros del proceso a partir de las señales vibro-acústicas, como línea natural de continuidad para futuras investigaciones. Abstract: This paper presents an analysis of the correlation between acoustic emission (AE signals and the main parameters of friction stir welding (FSW process, based on artificial neural networks (ANN. The AE signals have been acquired by the data acquisition instrument NI USB-9234, applied during the welding process carried out on plates of 3 mm thick of aluminium AA1050 alloy. Statistical and temporal parameters of discomposed EA signals using Wavelet Transform (WT have been used as input

  4. Redes de aprendizaje, aprendizaje en red Learning Networks, Networked Learning

    Directory of Open Access Journals (Sweden)

    Peter Sloep

    2011-10-01

    Full Text Available Las redes de aprendizaje (Learning Networks son redes sociales en línea mediante las cuales los participantes comparten información y colaboran para crear conocimiento. De esta manera, estas redes enriquecen la experiencia de aprendizaje en cualquier contexto de aprendizaje, ya sea de educación formal (en escuelas o universidades o educación no-formal (formación profesional. Aunque el concepto de aprendizaje en red suscita el interés de diferentes actores del ámbito educativo, aún existen muchos interrogantes sobre cómo debe diseñarse el aprendizaje en red para facilitar adecuadamente la educación y la formación. El artículo toma este interrogante como punto de partida, y posteriormente aborda cuestiones como la dinámica de la evolución de las redes de aprendizaje, la importancia de fomentar la confianza entre los participantes y el papel central que desempeña el perfil de usuario en la construcción de la confianza, así como el apoyo entre compañeros. Además, se elabora el proceso de diseño de una red de aprendizaje, y se describe un ejemplo en el contexto universitario. Basándonos en la investigación que actualmente se lleva a cabo en nuestro propio centro y en otros lugares, el capítulo concluye con una visión del futuro de las redes de aprendizaje.Learning Networks are on-line social networks through which users share knowledge with each other and jointly develop new knowledge. This way, Learning Networks may enrich the experience of formal, school-based learning and form a viable setting for professional development. Although networked learning enjoys an increasing interest, many questions remain on how exactly learning in such networked contexts can contribute to successful education and training. Put differently, how should networked learning be designed best to facilitate education and training? Taking this as its point of departure, the chapter addresses such issues as the dynamic evolution of Learning Networks

  5. Artificial cognition architectures

    CERN Document Server

    Crowder, James A; Friess, Shelli A

    2013-01-01

    The goal of this book is to establish the foundation, principles, theory, and concepts that are the backbone of real, autonomous Artificial Intelligence. Presented here are some basic human intelligence concepts framed for Artificial Intelligence systems. These include concepts like Metacognition and Metamemory, along with architectural constructs for Artificial Intelligence versions of human brain functions like the prefrontal cortex. Also presented are possible hardware and software architectures that lend themselves to learning, reasoning, and self-evolution

  6. Artificial Intelligence Study (AIS).

    Science.gov (United States)

    1987-02-01

    ARTIFICIAL INTELLIGNECE HARDWARE ....... 2-50 AI Architecture ................................... 2-49 AI Hardware ....................................... 2...ftf1 829 ARTIFICIAL INTELLIGENCE STUDY (RIS)(U) MAY CONCEPTS 1/3 A~NLYSIS AGENCY BETHESA RD R B NOJESKI FED 6? CM-RP-97-1 NCASIFIED /01/6 M |K 1.0...p/ - - ., e -- CAA- RP- 87-1 SAOFŔ)11 I ARTIFICIAL INTELLIGENCE STUDY (AIS) tNo DTICFEBRUARY 1987 LECT 00 I PREPARED BY RESEARCH AND ANALYSIS

  7. Artificial Intelligence in Astronomy

    Science.gov (United States)

    Devinney, E. J.; Prša, A.; Guinan, E. F.; Degeorge, M.

    2010-12-01

    From the perspective (and bias) as Eclipsing Binary researchers, we give a brief overview of the development of Artificial Intelligence (AI) applications, describe major application areas of AI in astronomy, and illustrate the power of an AI approach in an application developed under the EBAI (Eclipsing Binaries via Artificial Intelligence) project, which employs Artificial Neural Network technology for estimating light curve solution parameters of eclipsing binary systems.

  8. Quo Vadis, Artificial Intelligence?

    OpenAIRE

    Berrar, Daniel; Sato, Naoyuki; Schuster, Alfons

    2010-01-01

    Since its conception in the mid 1950s, artificial intelligence with its great ambition to understand and emulate intelligence in natural and artificial environments alike is now a truly multidisciplinary field that reaches out and is inspired by a great diversity of other fields. Rapid advances in research and technology in various fields have created environments into which artificial intelligence could embed itself naturally and comfortably. Neuroscience with its desire to understand nervou...

  9. Inteligencia artificial en vehiculo

    OpenAIRE

    Amador Díaz, Pedro

    2012-01-01

    Desarrollo de un robot seguidor de líneas, en el que se implementan diversas soluciones de las áreas de sistemas embebidos e inteligencia artificial. Desenvolupament d'un robot seguidor de línies, en el qual s'implementen diverses solucions de les àrees de sistemes encastats i intel·ligència artificial. Follower robot development of lines, in which various solutions are implemented in the areas of artificial intelligence embedded systems.

  10. STANFORD ARTIFICIAL INTELLIGENCE PROJECT.

    Science.gov (United States)

    ARTIFICIAL INTELLIGENCE , GAME THEORY, DECISION MAKING, BIONICS, AUTOMATA, SPEECH RECOGNITION, GEOMETRIC FORMS, LEARNING MACHINES, MATHEMATICAL MODELS, PATTERN RECOGNITION, SERVOMECHANISMS, SIMULATION, BIBLIOGRAPHIES.

  11. Desarrollo de un sistema basado en la visión artificial para el reconocimiento de placas vehiculares

    OpenAIRE

    Suárez Pino, José Antonio; Suárez Pino, José Antonio; Suárez Pino, José Antonio

    2011-01-01

    El presente trabajo describe el desarrollo del sistema de reconocimiento de placas vehiculares basado en visión artificial. En primer lugar, la placa es detectada dentro de la imagen digital usando las características de ancho, altura y área de los objetos que hay en la imagen. Después de ubicar la placa, los caracteres son extraídos de la imagen uno a uno. Finalmente, cada carácter es reconocido usando el algoritmo de redes neuronales artificial. Las pruebas de reconocimiento se realizaron t...

  12. Artificial life and life artificialization in Tron

    Directory of Open Access Journals (Sweden)

    Carolina Dantas Figueiredo

    2012-12-01

    Full Text Available Cinema constantly shows the struggle between the men and artificial intelligences. Fiction, and more specifically fiction films, lends itself to explore possibilities asking “what if?”. “What if”, in this case, is related to the eventual rebellion of artificial intelligences, theme explored in the movies Tron (1982 and Tron Legacy (2010 trat portray the conflict between programs and users. The present paper examines these films, observing particularly the possibility programs empowering. Finally, is briefly mentioned the concept of cyborg as a possibility of response to human concerns.

  13. Redes de Computadores (Transparencias temas de teoría del 1 al 9)

    OpenAIRE

    Gil Vázquez, Pablo

    2010-01-01

    Contenidos teóricos (Transparencias de los temas del 1 al 9) del curso de "Redes de Computadores" basados en la asignatura "Redes" de la titulación de "Ingeniería Técnica en Informática de Sistemas".

  14. Dynamic artificial neural networks with affective systems.

    Directory of Open Access Journals (Sweden)

    Catherine D Schuman

    Full Text Available Artificial neural networks (ANNs are processors that are trained to perform particular tasks. We couple a computational ANN with a simulated affective system in order to explore the interaction between the two. In particular, we design a simple affective system that adjusts the threshold values in the neurons of our ANN. The aim of this paper is to demonstrate that this simple affective system can control the firing rate of the ensemble of neurons in the ANN, as well as to explore the coupling between the affective system and the processes of long term potentiation (LTP and long term depression (LTD, and the effect of the parameters of the affective system on its performance. We apply our networks with affective systems to a simple pole balancing example and briefly discuss the effect of affective systems on network performance.

  15. Redes sociais e teoria social: revendo os fundamentos do conceitoRedes Sociales y Teoría Social: Reviendo los fundamentos del concepto

    Directory of Open Access Journals (Sweden)

    Sonia Acioli

    2007-12-01

    Full Text Available Este artigo discute os vários usos e abordagens utilizadas em relação à expressão redes sociais, que tem sido naturalizada e associada apenas às tecnologias da informação. É um estudo conceitual que pretende situar historicamente a noção de redes, buscando ainda identificar as formas as quais a expressão redes sociais tem sido articulada e as abordagens empreendidas. Para tal, foi realizada uma revisão bibliográfica tendo como base os campos da Sociologia, Antropologia, Informação e Comunicação por serem essas as áreas aonde a noção de redes teve sua origem sendo também mais freqüentemente utilizada. Buscando pensar as possibilidades de análise utilizando a noção de rede, esboçamos três possíveis abordagens inspiradas na leitura de Barnes, J. A. e Mitchell, J. Clyde. São elas: uma abordagem metafórica, voltada à filosofia de rede ou ainda a uma aproximação conceitual; uma analítica centrada na metodologia de análise de redes, e, uma tecnológica, cuja preocupação está voltada para as redes de conexões, para as possibilidades que se colocam em relação às interações possíveis na sociedade através de redes eletrônicas, de informações, interorganizacionais. Entendemos que em todas essas abordagens dá-se uma relação direta com a informação, se percebemos informação como processo de troca permanente. Portanto, trabalhar com a idéia de redes significa trabalhar de forma articulada com a idéia de informação. Concluindo, nesse mundo em redes, onde há mais quantidade do que qualidade de informação, a possibilidade de fragmentação de saberes e culturas, e, portanto de sujeitos é muito grande. Nesse sentido, pode-se pensar na relativização dos espaços internos - entendidos como o local – além da valorização desses mesmos espaços, já que as ordens local e global se interpenetram e podem reinventar formas de comunicação e saberes.

  16. REDES DE COOPERAÇÃO COMO VANTAGEM COMPETITIVA: ESTUDO DE CASO DE UMA REDE DE SUPERMERCADOS NO RIO GRANDE DO SUL

    Directory of Open Access Journals (Sweden)

    Anelise Rebelato Mozzato

    2011-03-01

    Full Text Available Este artigo propõe analisar uma rede de cooperação entre supermercados de pequenos e médios portes que têm encontrado dificuldades para atuar de maneira isolada em mercados cada vez mais competitivos. Para pequenas e médias empresas de setores variados, as redes de cooperação têm sido o meio encontrado para sobreviver e competir com grandes organizações. Dessa forma, o presente estudo tem como objetivo central realizar análises relacionais e macroestruturais na Rede Super Útil de supermercados da cidade de Passo Fundo, investigando a cooperação interorganizacional como alternativa competitiva. Para tanto, foi realizada uma pesquisa qualitativo-exploratória, seguindo o método do estudo de caso. Para a coleta e análise dos dados foram estabelecidas categorias de análise: tipologia de redes de cooperação, pressupostos à configuração de redes de cooperação e benefícios advindos da rede de cooperação. Das entrevistas semiestruturadas realizadas junto ao presidente da rede, ao gestor administrativo da rede, com os proprietários dos supermercados associados, e também da análise de material institucional e informativos impressos e eletrônicos, emergiram resultados que foram analisados à luz do referencial teórico pertinente. Os resultados identificam, entre outros aspectos, que a rede investigada mantém relações de cooperação, obtendo vantagens competitivas neste sistema de cooperação, apresentando-se como um caso de relacionamento interorganizacional de cooperação de sucesso que continua em processo de aprimoramento e inovação; é uma rede horizontal e formal que apresenta três condições fundamentais para a sua formação: objetivos comuns, interação e gestão. Por fim, salienta-se que a Rede Super Útil constitui-se numa alternativa estratégica que obtém vantagens competitivas no contexto em que se insere.

  17. Indústria de tabaco e cidadania: confronto entre redes organizacionais

    OpenAIRE

    Boeira, Sérgio Luís

    2006-01-01

    O artigo aborda a história da indústria de tabaco no Brasil e da formação de sua rede estratégica, bem como da rede dos atores sociais que a contrapõem. Na primeira parte, apresenta-se uma correlação entre a história da produção industrial, do consumo de tabaco e do antitabagismo. Na segunda parte são apresentados os conceitos de rede estratégica e de rede multifragmentária (antifumo), propostos para facilitar a compreensão de alguns dos múltiplos aspectos conflitivos entre as duas redes. A p...

  18. Neuronal Migration Disorders

    Science.gov (United States)

    ... Understanding Sleep The Life and Death of a Neuron Genes At Work In The Brain Order Publications ... birth defects caused by the abnormal migration of neurons in the developing brain and nervous system. In ...

  19. Motor Neuron Diseases

    Science.gov (United States)

    ... and other neurodegenerative diseases to better understand the function of neurons and other support cells and identify candidate therapeutic ... and other neurodegenerative diseases to better understand the function of neurons and other support cells and identify candidate therapeutic ...

  20. ESTADO DEL ARTE EN REDES VANET Y CADENAS DE MARKOV

    Directory of Open Access Journals (Sweden)

    Jorge Blanco

    2012-02-01

    Full Text Available El  presente  artículo  resume  el  estado  del  arte  de  las redes  VANET  como  una  extensión  de  las  redes MANET,  por  tener  características  particulares  en cuanto a la forma de construir topologías que cambian   dinámicamente  en  el  tiempo,  en  tal  sentido,  se proponen los argumento para que en futuros trabajos de  investigación,  se  haga  un  análisis  no  desde  el punto  vista  de  simulación,  sino  desde  el  punto  de vista  matemático  para  que  se  desarrolle  a  través  de cadenas de Markov, ya que la construcción de redes VANET corresponde o puede verse como  un proceso estocástico    discreto,    que    puede   ser   analizado matemáticamente por medio de dichas cadenas,  con el fin de garantizar una  entrega confiable de paquetes de  información  entre  vehículos  los  cuales  están entrando  y  saliendo  constantemente  dentro  de  la topología de red.

  1. Redes sociais e o marketing de inovações.

    Directory of Open Access Journals (Sweden)

    Diógenes Manoel Leiva Martin

    2008-02-01

    Full Text Available O entendimento da dinâmica da adoção de novas tecnologias pelos consumidores torna-se cada vez mais importante dada a velocidade de surgimento de inovações. Para a área de marketing, novos desafios surgem, pois o avanço tecnológico pode criar diferentes perfis de usuários de produtos, implicando a necessidade de implementação de novos mecanismos de sensibilização do consumidor. Considerando o marketing boca a boca num contexto de redes sociais, este artigo procura avaliar a difusão do uso de novas tecnologias. Por meio de uma modelagem estocástica, são simuladas computacionalmente populações com graus diferentes de conexões nas redes sociais, e é estimada a evolução da proporção de usuários de uma nova tecnologia. O uso da modelagem estocástica permite a análise de fenômenos complexos que dificilmente poderiam ser avaliados de forma empírica, por causa da problemática de criação de constructos, de levantamento de dados, de adequação de estimativas de parâmetros à realidade de novas tecnologias e de limitação das ferramentas estatísticas. Os resultados do modelo sugerem que o fortalecimento de vínculos entre indivíduos e a implementação de programas de marketing que explorem as interações nas redes sociais constituem importantes estratégias para o aumento da velocidade de difusão de tecnologias.

  2. Redes urbanas de mobilização digital

    Directory of Open Access Journals (Sweden)

    Salvatore Barreto Benvenuto

    2014-03-01

    Full Text Available O advento de uma rede mundial de computadores estabeleceu um novo trânsito na cidade. O fluxo da informação constituiu um amálgama com os processos de produção, pessoais e institucionais através de um "território" (ciberespaço onde os mesmos podem se exercer no mesmo lugar ao mesmo tempo. A cidade apresenta assim uma contraparte virtual (FIRMINO 2005. Os reflexos da Era da informação (CASTELLS 2005 estão por toda parte, no tráfego, nas escolas, criando uma faceta digital do processo material. Mas, eventualmente, o inverso acontece. Os diversos movimentos políticos organizados pela via digital também estabelecem referenciais, pontos de encontro, vias para as suas marchas em seus paralelos materiais. Tais mecanismos de mobilização frequentemente utilizam certos lugares como marcos simbólicos capazes de dar significado às suas reivindicações. Estas redes de mobilização digital reclamam a ocupação do espaço representativo, rico em sentido, capaz de incorporar a organização virtual. Este artigo visa explorar a ocupação do espaço físico como reflexo das mobilizações através das redes sociais. Procura, dessa forma, debater a intensa relação entre espaço real e digital pela via política.

  3. (INTERSUBJETIVIDADE NOS ESTUDOS DE REDES SOCIAIS: DISSOLVENDO FRONTEIRAS

    Directory of Open Access Journals (Sweden)

    Sayonara Costa

    2014-07-01

    Full Text Available As redes sociais da internet (RSI se multiplicam e todas elas, embora tenham esquemas enunciativos distintos, ampliam as possibilidades de por em cena (intersubjetividades. Muitos papeis sociais são desempenhados nesses ambientes digitais que dão guarida às múltiplas faces de um sujeito que se (desconstrói em meio a um processo heterogêneo. Diante disso, a pergunta que norteia esse ensaio é: Como estudar esse processo de (desconstrução da subjetividade em redes sociais? A proposição que defendemos neste trabalho é a de que o sujeito adepto das redes sociais da internet encontra-se em um tempo-espaço propício a excitações que vão muito além das percepções idiossincráticas de cada indivíduo. Em função disso, propomos que estudar as (intersubjetividades nas RSI pode ser produtivo se relacionarmos as noções de caosmose (Guattari, self (Goffman e enunciação linguística (Benveniste. A conclusão a que chegamos é a de que o viés da enunciação linguística pode ser uma alternativa metodológica que auxilie na conexão entre uma concepção mais transversalista da subjetividade e a tese de que a interação social assemelha-se a uma encenação teatral e, por isso, pode tomar rumos diversos, de acordo com roteiros pré-estabelecidos e socialmente partilhados nos cenários digitais das RSI.

  4. Control de Robots Móviles con Incertidumbres Dinámicas usando Redes de Base Radial

    Directory of Open Access Journals (Sweden)

    Francisco G. Rossomando

    2010-10-01

    Full Text Available Resumen: En este trabajo se presenta un control de seguimiento de trayectorias de robots móviles. La estructura de control propuesta combina una linealización por realimentación basada en el modelo cinemático nominal, y una red neuronal directa para el control dinámico adaptable. La dinámica del robot es aprendida por una red neuronal basada en funciones de base radial (RN-FBR en un lazo de realimentación adaptable, ajustando el peso y las funciones de base radial. Se muestra un análisis de estabilidad del sistema de neuro-control adaptable. Se comprueba que los errores de control están limitados en función del error de aproximación de la RN-FBR. El funcionamiento del controlador también se verifica experimentalmente. Palabras clave: robot móvil, control no lineal, redes neuronales, control adaptable, funciones de base radial

  5. Redes de ruido en emulsiones holográficas

    OpenAIRE

    Beléndez Vázquez, Augusto; Carretero López, Luis; Fimia Gil, Antonio; Fuentes Rosillo, Rosa; Pascual Villalobos, Inmaculada

    1992-01-01

    Se estudian las redes de ruido holográficas registradas en emulsiones fotográficas blanquadas haciendo uso de un único haz de registro. Asimismo se analizan y discuten los resultados experimentales obtenidos con procesados típicos de las emulsiones blanqueadas, como son los blanqueos solvente y de rehalogenación, cuando se analiza la transmitancia de las placas holográficas en función del ángulo de reconstrucción. Holographic noise gratings recorded in bleached silver halide emulsions with...

  6. Aplicación de las Redes Neuronales en Medicina

    Directory of Open Access Journals (Sweden)

    Alberto Delgado

    1999-10-01

    Full Text Available Las redes neuronales artificiales son modelos matemáticos que pueden ser entrenados para aprender relaciones no lineales entre un conjunto de datos de entrada y un conjunto de datos de salida. En medicina la aplicación más común de estos modelos, es la clasificación de patrones con el propósito de apoyar al médico en el diagnóstico y tratamiento del paciente.

  7. Técnicas de reconocimiento facial mediante redes neuronales

    OpenAIRE

    Cabello Pardos, Enrique

    2011-01-01

    En esta Tesis se exploran soluciones a la verificación facial. Se han estudiado técnicas basadas en imágenes bidimensionales y se ha realizado un estudio inicial basado en un modelo tridimensional de la cara. Se han comparado tres clasificadores (k vecinos más cercanos, redes neuronales del tipo ñmciones de base radial y máquinas de vector soporte), mostrando los resultados obtenidos con los diferentes datos de entrada. En dos dimensiones se han propuesto dos técnicas de reducción de...

  8. La Influencia de las redes sociales en el aprendizaje colaborativo

    OpenAIRE

    Garrigós, Irene; Mazón, Jose-Norberto; Saquete, Estela; Puchol, Marcel; Moreda, Paloma

    2010-01-01

    Actualmente las redes sociales representan un mecanismo para que un conjunto de personas puedan potenciar su comunicación, cooperar entre ellas en tareas comunes y sentirse parte de una comunidad. Estas características hacen pensar que su uso sería conveniente en entornos educativos con el fin de potenciar diversos aspectos como: participación del alumnado en el proceso de aprendizaje, aprendizaje autónomo, interacción y motivación de los alumnos, creatividad del ...

  9. Migrantes culiacanenses en California: Diversidad en sus redes migratorias

    OpenAIRE

    Sánchez Sánchez, Ernesto

    2012-01-01

    Es un hecho la dinámica extraordinaria que tienen los lugares de reciente migración, ya sea como lugares de origen o destino. El estado de Sinaloa se suma a esta dinámica en la cual aparecen ahora sus tres principales zonas urbanas -Culiacán, Mazatlán y Ahome- dentro de su mapa migratorio. Sin embargo la migración, como proceso social, implica una serie de interrelaciones formadas tiempo atrás. Éstas repercuten en la conformación de las nuevas redes migratorias. No obstante, durante décadas, ...

  10. Las familias homoparentales y sus redes de apoyo social

    OpenAIRE

    González Rodríguez, María del Mar; Sánchez, M. Ángeles

    2003-01-01

    Este trabajo tiene como objetivo avanzar en conocimiento con respecto a las familias homoparentales, estudiando sus redes de apoyo social, aspecto crucial en cualquier contexto familiar. Se estudiaron 28 familias homoparentales con hijos o hijas entre los 3 y los 16 años. De ellas, 15 provenían de la Comunidad Andaluza y 13 de la Comunidad de Madrid. Los resultados indican que estas familias disponen de una red amplia de figuras de apoyo, que incluye tanto a familiares como a amistades, así c...

  11. Videojuegos en redes sociales: aprender desde experiencias óptimas

    OpenAIRE

    Esnaola Horacek, Graciela; Levis, Diego

    2009-01-01

    Desarrollaremos conceptos de interés académico acerca de las posibilidades educativas que actualmente ofrecen los entornos lúdicos en la Web 2.0, capturando el interés generalizado de los estudiantes. Destacaremos una definición particular de videojuego aplicando determinadas categorías de análisis a las propuestas lúdicas que ofrecen las redes sociales, en especial el caso Facebook. La línea que destacamos durante nuestra trayectoria de investigación se ubica en los entrecruzamientos que ...

  12. Análisis de accesibilidad de redes sociales

    OpenAIRE

    Crespo Romero, Verónica

    2013-01-01

    Las plataformas de Redes Sociales, basadas esencialmente en tecnologías Web 2.0, han abierto un mundo de posibilidades para el estudio, el trabajo y el ocio. Permiten a los usuarios crear y publicar sus propios contenidos, compartirlos e interactuar con otros usuarios en todo el mundo, en tiempo real o prácticamente en tiempo real. Han dado pie a todo un nuevo fenómeno social y se han convertido en una parte importante de las interacciones sociales, tales como establecer nuevas amistades, apo...

  13. Las redes sociales y sus factores de riesgos

    OpenAIRE

    Veloz Aguilar, Andrea Paola

    2017-01-01

    La red de Internet crece cada día más, a medida que las personas van conociendo este recurso tecnológico, va despertando principalmente en los jóvenes una gran  curiosidad por conocer páginas que muestren contenido no apto para menores, lo que ha ocasionado un gran problema en el uso indebido de las redes sociales, tales como la adicción principalmente de jóvenes, el abandono de otras formas de entretenimiento, la pérdida de oportunidades de realizarse en otros ámbitos. Sin embargo, a pa...

  14. O consumidor insatisfeito em tempo de redes sociais

    Directory of Open Access Journals (Sweden)

    Viviane Fushimi Velloso

    2014-01-01

    Full Text Available Este estudo apresenta o perfil de comportamento do consumidor que utiliza os Sites de Redes Sociais para solucionar e compartilhar suas insatisfações. Destaca o processo percorrido para chegar até a publicação online de seus casos e suas expectativas sobre o atendimento pós-venda online. Esta tendência de relacionamento tende a se ampliar. Desta forma, o estudo possibilitou apontar algumas falhas atuais no relacionamento entre organização e consumidor, para que se alcance eficiência e eficácia na relação online.

  15. Aplicaciones sobre plataformas de redes neuronales en tiempo real

    OpenAIRE

    Tosini, Marcelo Alejandro; Acosta, Nelson

    2003-01-01

    El presente trabajo pretende el diseño de una metodología para la construcción de aplicaciones basadas en redes neuronales sobre una plataforma Muren. Las aplicaciones se restringen a sistemas de control y reconocimiento de patrones por imágenes. Se describe la arquitectura del sistema de desarrollo Muren, basado en 2 procesadores ZISC de 78 neuronas cada uno, una FPGA Spartan II, bancos de memoria y lógica adicional de comunicación.

  16. Las redes sociales directivas externas y la estrategia corporativa.

    OpenAIRE

    Fernández Pérez, Virginia

    2008-01-01

    Este trabajo pretende aportar un punto de vista más amplio sobre el desarrollo de la toma de decisiones directiva relacionada con la elección e implantación de la estrategia corporativa, para lo que incorpora las redes sociales externas de los directivos como elemento explicativo del proceso, ya que son fuentes de información y referencias sociales muy importantes. Los contactos sociales pueden condicionar en gran medida el comportamiento estratégico de la organización y por tanto, su desempe...

  17. O impacto das redes sociais no marketing: perspectiva portuguesa

    OpenAIRE

    Rosa, Nuno Gonçalo Henriques da

    2010-01-01

    Mestrado em Marketing As mudanças ocorridas nos últimos anos, no panorama dos media, associados aos desenvolvimentos tecnológicos, originaram novos comportamentos no consumidor. O poder das comunicações das marcas deixou de estar centrada apenas nas iniciativas das empresas, o que permitiu um novo relacionamento das marcas com o consumidor, transformando-o num Prosumer. As Redes Sociais e a importância que as suas plataformas assumem na nossa vida, o que para alguns autores é uma extensão ...

  18. Movimientos sociales, redes sociales y recursos simbólicos

    Directory of Open Access Journals (Sweden)

    Amaro La Rosa

    2016-11-01

    Full Text Available El artículo presenta una visión actualizada del papel que desempeñan las redes sociales en los movimientos sociales contemporáneos. Se realiza una somera revisión de la teoría de los movimientos sociales y sus implicancias, enfatizando en su vinculación con procesos de comunicación y narrativas específicas. Finaliza con el recuento de algunos recursos simbólicos empleados por movimientos sociales en diversas realidades.

  19. Aplicaciones de redes neuronales en economía.

    Directory of Open Access Journals (Sweden)

    Pacheco Bonrostro, J.

    1997-01-01

    Full Text Available La metodología de las Redes Neuronales Artificiales, está siendo usada con profusión, dentro del campo de la Economía, hasta tal punto que existe una publicación bimensual, que trata específicamente estas aplicaciones a los mercados financieros: Neurove$t Journal. En este trabajo, se presentan las principales líneas de investigación existentes, a continuación la que nosotros estamos siguiendo, con algunos resultados iniciales, para finalizar con las líneas a seguir y una selección bibliográfica.

  20. Planificación y diseño de redes FTTH basadas en zonificación y servicios

    OpenAIRE

    Cortes, Antonio

    2017-01-01

    El objetivo en esta investigación es proponer un mejor entendimiento en la planificación y diseño de redes FTTH en combinación con las redes GPON. Para lograr este mejor entendimiento se diseña un escenario experimental, al tomar como referencia el contexto de las redes de próxima generación, se encuentran las redes FTTH (Redes multiservicio por fibra óptica hacia la casa de cada usuario) que vienen a cubrir una gran demanda, como el ancho de banda y la prestación de servicios que ofrecen las...

  1. [Total artificial heart].

    Science.gov (United States)

    Antretter, H; Dumfarth, J; Höfer, D

    2015-09-01

    To date the CardioWest™ total artificial heart is the only clinically available implantable biventricular mechanical replacement for irreversible cardiac failure. This article presents the indications, contraindications, implantation procedere and postoperative treatment. In addition to a overview of the applications of the total artificial heart this article gives a brief presentation of the two patients treated in our department with the CardioWest™. The clinical course, postoperative rehabilitation, device-related complications and control mechanisms are presented. The total artificial heart is a reliable implant for treating critically ill patients with irreversible cardiogenic shock. A bridge to transplantation is feasible with excellent results.

  2. Signals and Circuits in the Purkinje Neuron

    Directory of Open Access Journals (Sweden)

    Ze'ev R Abrams

    2011-09-01

    Full Text Available Purkinje neurons in the cerebellum have over 100,000 inputs organized in an orthogonal geometry, and a single output channel. As the sole output of the cerebellar cortex layer, their complex firing pattern has been associated with motor control and learning. As such they have been extensively modeled and measured using tools ranging from electrophysiology and neuroanatomy, to dynamic systems and artificial intelligence methods. However, there is an alternative approach to analyze and describe the neuronal output of these cells using concepts from Electrical Engineering, particularly signal processing and digital/analog circuits. By viewing the Purkinje neuron as an unknown circuit to be reverse-engineered, we can use the tools that provide the foundations of today’s integrated circuits and communication systems to analyze the Purkinje system at the circuit level. We use Fourier transforms to analyze and isolate the inherent frequency modes in the Purkinje neuron and define 3 unique frequency ranges associated with the cells’ output. Comparing the Purkinje neuron to a signal generator that can be externally modulated adds an entire level of complexity to the functional role of these neurons both in terms of data analysis and information processing, relying on Fourier analysis methods in place of statistical ones. We also re-describe some of the recent literature in the field, using the nomenclature of signal processing. Furthermore, by comparing the experimental data of the past decade with basic electronic circuitry, we can resolve the outstanding controversy in the field, by recognizing that the Purkinje neuron can act as a multivibrator circuit.

  3. Redes Sociales en el Contexto de Cambio Organizacional

    Directory of Open Access Journals (Sweden)

    Sérgio Ricardo Vieira

    2015-01-01

    Full Text Available La presente investigación tiene como principal objetivo comprobar si ocurren alteraciones en las redes intraorganizacionales de una empresa pública, llevando en cuenta las intervenciones de cambio organizacional. Para ello, se realiza el mapeamiento de las redes de amistad y comunicación de la empresa, a través de un cuestionario aplicado a los empleados en dos diferentes momentos: durante la implantación del cambio y once meses después de la primera aplicación. Las respuestas son organizadas en matrices, posteriormente analizadas con el software Unicet. Los resultados obtenidos revelan impactos más significativos en la red de amistad: reducción en el tamaño de la red y disminución de la distancia geodésica. Se observa un impacto positivo en la red de comunicación: aunque haya ocurrido una reducción en el tamaño, el cambio la impacta poco. Los resultados obtenidos contradicen la literatura en la que se basa el presente estudio, puesto que ella afirma que, tras un proceso de cambio, la red de comunicación presenta mayores diferencias.

  4. apoio, rede social e papéis na familia

    Directory of Open Access Journals (Sweden)

    Jaqueline Dias

    2007-01-01

    Full Text Available La finalidad de este trabajo es identificar apoyos sociales, redes y roles en las familias de docentes de enfermería, utilizando para ello, la fundamentación teórica sobre promoción de salud en enfermería familiar. El escenario de este estudio fue un Curso de Pregrado en Enfermería de una Universidad del interior de Brasil. Como sujetos de este estudio fueron seleccionadas tres familias de enfermeras docentes, responsables por disciplinas del ciclo profesionalizante. Para la recolección de los datos se utilizó la entrevista en profundidad, el genograma y el ecomapa. Los datos fueron catalogados mediante el análisis de contenido, eligiéndose el tipo temático. En las tres familias estudiadas, los familiares y la familia ampliada se constituyeron en la principal fuente de apoyo. Fueron consideradas como importantes las funcionarias, sin lazos de consanguinidad; las redes de apoyo, compuestas por la escuela, el trabajo, la iglesia y sitios de ocio. La identificación de roles y apoyos les permitió a los familiares fortalecer los mecanismos de enfrentamiento para lidiar con los factores cotidianos estresantes y actuar en la promoción de la salud.

  5. O apoio da rede social a transexuais femininas

    Directory of Open Access Journals (Sweden)

    Milene Soares

    2011-04-01

    Full Text Available O presente estudo teve como objetivo compreender a relação atual de transexuais femininas com suas redes sociais. Participaram cinco pacientes submetidas à cirurgia de transgenitalização em um hospital público do interior do Estado de São Paulo, Brasil. Elas responderam à entrevista semi-estruturada e a perguntas para a construção de Genogramas e Mapas de Rede. Os dados foram compreendidos de forma qualitativa a partir da teoria sistêmico-cibernética novo paradigmática. As entrevistadas relataram situações em que sentiram apoio, inclusive diante da decisão de operar, mas também descreveram situações nas quais sentiram humilhação e exclusão pelo fato de expressarem e viverem sua sexualidade de forma diferente da maioria das pessoas. O estudo mostrou que ainda prevalece a posição heteronormativa, sustentando preconceitos e atos de discriminação direcionados às mulheres transexuais.

  6. REDES TECNOLÓGICAS APLICADAS EM EaD

    Directory of Open Access Journals (Sweden)

    Suélly Lima dos Santos

    2011-08-01

    Full Text Available Com o advento da internet e o aparecimento das novas tecnologias educacionais, conjunto de informações e comunicações (telefone, internet, rádio, vídeo, computador e televisão, ultrapassaram as fronteiras das quatro paredes da sala de aula, surgindo ambientes virtuais direcionadas à ampliação da participação dos serviços públicos relacionados ao ensino. À educação e à formação técnica e profissional permitiu-se o aumento da interatividade através da tecnologia, promovendo maneiras de acesso ao aluno utilizando computadores e/ou dispositivos móveis que viabiliza a Educação à Distância (EaD. Devido o grande crescimento do ensino à distância, as instituições já utilizam redes de dados para ampliar o acesso de aprendizagem. Com este espantoso aumento das redes, e da acelerada transmissão de informações aprender como elas funcionam é muito importante, além do mais usando a própria tecnologia para este fim. Como conclusão deste trabalho as mudanças relâmpadas da grande disponibilidade de dados no ambiente virtual é de enorme valia para o processo ensino-aprendizado.

  7. La Inteligencia Artificial aplicada a la toma de decisiones en la Empresa de Internet

    Directory of Open Access Journals (Sweden)

    Mª Carmen Lozano Gutiérrez

    2004-09-01

    Full Text Available En el presente documento de trabajo se presenta una aplicación de una metodología basada en distintas técnicas de Inteligencia Artificial (redes neuronales, lógica difusa, así como técnicas bio-inspiradas basadas en el comportamiento de las hormigas al proceso de toma de decisiones de la empresa en red, para la consecución de un objetivo concreto como es el de lograr la maximización de los enlaces recorridos así como el logro de una óptima usabilidad del sitio.

  8. Redes neuronales artificiales para la predicción de la calidad en soldadura por resistencia por puntos

    Directory of Open Access Journals (Sweden)

    Martín, O.

    2006-10-01

    Full Text Available An artificial neural network is proposed as a tool for predicting from three parameters (weld time, current intensity and electrode sort if the quality of a resistance spot weld reaches a certain level or not. The quality is determined by cross tension testing. The fact of reaching this quality level or not is the desired output that goes with each input of the artificial neural network during its supervised learning. The available data set is made up of input/desired output pairs and is split randomly into a training subset (to update synaptic weight values and a validation subset (to avoid overfitting phenomenon by means of cross validation.

    Se propone una red neuronal artificial como herramienta para predecir, a partir de tres parámetros operativos (tiempo de soldadura, intensidad de corriente y tipo de electrodo, si la calidad de una unión soldada por resistencia por puntos alcanza o no un cierto nivel. El entrenamiento de la red neuronal conlleva que la calidad se determine previamente mediante ensayos de tracción en probetas en cruz. El hecho de alcanzar o no el citado nivel de calidad constituye la respuesta objetivo que acompaña a cada entrada de la red neuronal artificial durante su aprendizaje supervisado. El conjunto de datos disponible está formado por pares entrada/salida objetivo y se divide de forma aleatoria en un subconjunto de entrenamiento (para actualizar los valores de los pesos sinápticos y en un subconjunto de validación (para combatir el fenómeno de overfitting mediante validación cruzada.

  9. Bibliography: Artificial Intelligence.

    Science.gov (United States)

    Smith, Richard L.

    1986-01-01

    Annotates reference material on artificial intelligence, mostly at an introductory level, with applications to education and learning. Topics include: (1) programing languages; (2) expert systems; (3) language instruction; (4) tutoring systems; and (5) problem solving and reasoning. (JM)

  10. Artificial intelligence in medicine.

    OpenAIRE

    Ramesh, A. N.; Kambhampati, C.; Monson, J. R. T.; Drew, P. J.

    2004-01-01

    INTRODUCTION: Artificial intelligence is a branch of computer science capable of analysing complex medical data. Their potential to exploit meaningful relationship with in a data set can be used in the diagnosis, treatment and predicting outcome in many clinical scenarios. METHODS: Medline and internet searches were carried out using the keywords 'artificial intelligence' and 'neural networks (computer)'. Further references were obtained by cross-referencing from key articles. An overview of ...

  11. Minimally Naturalistic Artificial Intelligence

    OpenAIRE

    Hansen, Steven Stenberg

    2017-01-01

    The rapid advancement of machine learning techniques has re-energized research into general artificial intelligence. While the idea of domain-agnostic meta-learning is appealing, this emerging field must come to terms with its relationship to human cognition and the statistics and structure of the tasks humans perform. The position of this article is that only by aligning our agents' abilities and environments with those of humans do we stand a chance at developing general artificial intellig...

  12. Artificial Intelligence Project

    Science.gov (United States)

    1990-01-01

    Symposium on Aritificial Intelligence and Software Engineering Working Notes, March 1989. Blumenthal, Brad, "An Architecture for Automating...Artificial Intelligence Project Final Technical Report ARO Contract: DAAG29-84-K-OGO Artificial Intelligence LaboratO"ry The University of Texas at...Austin N>.. ~ ~ JA 1/I 1991 n~~~ Austin, Texas 78712 ________k A,.tificial Intelligence Project i Final Technical Report ARO Contract: DAAG29-84-K-0060

  13. Artificial intelligence in cardiology

    OpenAIRE

    Bonderman, Diana

    2017-01-01

    Summary Decision-making is complex in modern medicine and should ideally be based on available data, structured knowledge and proper interpretation in the context of an individual patient. Automated algorithms, also termed artificial intelligence that are able to extract meaningful patterns from data collections and build decisions upon identified patterns may be useful assistants in clinical decision-making processes. In this article, artificial intelligence-based studies in clinical cardiol...

  14. Principles of artificial intelligence

    CERN Document Server

    Nilsson, Nils J

    1980-01-01

    A classic introduction to artificial intelligence intended to bridge the gap between theory and practice, Principles of Artificial Intelligence describes fundamental AI ideas that underlie applications such as natural language processing, automatic programming, robotics, machine vision, automatic theorem proving, and intelligent data retrieval. Rather than focusing on the subject matter of the applications, the book is organized around general computational concepts involving the kinds of data structures used, the types of operations performed on the data structures, and the properties of th

  15. Intelligence: Real or artificial?

    OpenAIRE

    Schlinger, Henry D.

    1992-01-01

    Throughout the history of the artificial intelligence movement, researchers have strived to create computers that could simulate general human intelligence. This paper argues that workers in artificial intelligence have failed to achieve this goal because they adopted the wrong model of human behavior and intelligence, namely a cognitive essentialist model with origins in the traditional philosophies of natural intelligence. An analysis of the word “intelligence” suggests that it originally r...

  16. Training Spiking Neural Models Using Artificial Bee Colony

    Science.gov (United States)

    Vazquez, Roberto A.; Garro, Beatriz A.

    2015-01-01

    Spiking neurons are models designed to simulate, in a realistic manner, the behavior of biological neurons. Recently, it has been proven that this type of neurons can be applied to solve pattern recognition problems with great efficiency. However, the lack of learning strategies for training these models do not allow to use them in several pattern recognition problems. On the other hand, several bioinspired algorithms have been proposed in the last years for solving a broad range of optimization problems, including those related to the field of artificial neural networks (ANNs). Artificial bee colony (ABC) is a novel algorithm based on the behavior of bees in the task of exploring their environment to find a food source. In this paper, we describe how the ABC algorithm can be used as a learning strategy to train a spiking neuron aiming to solve pattern recognition problems. Finally, the proposed approach is tested on several pattern recognition problems. It is important to remark that to realize the powerfulness of this type of model only one neuron will be used. In addition, we analyze how the performance of these models is improved using this kind of learning strategy. PMID:25709644

  17. Paradigma. Hacia el diseño y desarrollo de algoritmos y sistemas de control para clonación artificial en procesos industriales.

    Directory of Open Access Journals (Sweden)

    Jairo Amador

    2004-11-01

    Full Text Available Haciendo uso de Ia tecnología inteligente basada en la lógica difusa, las redes neuronales y los algoritmos genéticos, se pretende plantear un paradigma para la clonación artificial de dispositivos en procesos industriales, específicamente para sensores, los cuales deberán replicar las mismas o mejores funciones de los dispositivos reales mediante la evolución des comportamiento.

  18. Implantacao da Rede Amamenta Brasil e prevalencia de aleitamento materno exclusivo

    Directory of Open Access Journals (Sweden)

    Adriana Passanha

    2013-12-01

    Full Text Available OBJETIVO : Analisar a associação entre grau de implantação da Rede Amamenta Brasil e prevalência de aleitamento materno exclusivo. MÉTODOS : Estudo transversal, com amostra representativa de 916 crianças < 6 meses em Ribeirão Preto, SP, em 2011. Foram coletados dados sobre aleitamento materno, local de acompanhamento ambulatorial e demais características, durante a Campanha Nacional de Vacinação. O fator de estudo correspondeu ao local de acompanhamento ambulatorial: Privado; Público não Rede; Público com Oficina da Rede; e Público certificado na Rede. O efeito individualizado do fator de estudo sobre o desfecho foi avaliado mediante análise de regressão de Poisson com variância robusta. RESULTADOS : A comparação entre os locais privados (categoria de referência e os demais mostrou relação dose-resposta significativa com elevação progressiva da prevalência de aleitamento materno exclusivo em locais públicos não Rede, em locais públicos com Oficina da Rede e em locais públicos certificados na Rede (p = 0,047. A Razão de Prevalência para amamentação exclusiva foi igual a 1,47 (IC95% 1,00;2,17 para o estrato das Unidades Básicas de Saúde certificadas na Rede, após ajuste pelas variáveis de confusão. CONCLUSÕES : A prevalência de aleitamento materno exclusivo em < 6 meses foi maior nos locais certificados na Rede, evidenciando a relevância de investir na certificação de Unidades Básicas de Saúde nessa ação.

  19. Modeling the Development of Goal-Specificity in Mirror Neurons.

    Science.gov (United States)

    Thill, Serge; Svensson, Henrik; Ziemke, Tom

    2011-12-01

    Neurophysiological studies have shown that parietal mirror neurons encode not only actions but also the goal of these actions. Although some mirror neurons will fire whenever a certain action is perceived (goal-independently), most will only fire if the motion is perceived as part of an action with a specific goal. This result is important for the action-understanding hypothesis as it provides a potential neurological basis for such a cognitive ability. It is also relevant for the design of artificial cognitive systems, in particular robotic systems that rely on computational models of the mirror system in their interaction with other agents. Yet, to date, no computational model has explicitly addressed the mechanisms that give rise to both goal-specific and goal-independent parietal mirror neurons. In the present paper, we present a computational model based on a self-organizing map, which receives artificial inputs representing information about both the observed or executed actions and the context in which they were executed. We show that the map develops a biologically plausible organization in which goal-specific mirror neurons emerge. We further show that the fundamental cause for both the appearance and the number of goal-specific neurons can be found in geometric relationships between the different inputs to the map. The results are important to the action-understanding hypothesis as they provide a mechanism for the emergence of goal-specific parietal mirror neurons and lead to a number of predictions: (1) Learning of new goals may mostly reassign existing goal-specific neurons rather than recruit new ones; (2) input differences between executed and observed actions can explain observed corresponding differences in the number of goal-specific neurons; and (3) the percentage of goal-specific neurons may differ between motion primitives.

  20. Análisis de sistema de potencia desbalanceado con el empleo de herramientas estadísticas, coeficientes complejos y redes neuronales artificiales; Statistical, Complex Factor and Neural Networks Analysis and Simulation of an Unbalance Power Systems

    Directory of Open Access Journals (Sweden)

    Marcos A de Armas Teyra

    2011-02-01

    Full Text Available Se caracteriza estadísticamente el desbalance de tensión en un sistema eléctrico de potencia en términos de laIEEE y se señalan algunas informaciones útiles adicionales que se obtienen de esta. Se muestra cuán sostenidapuede ser la explotación de un conjunto de potentes motores asincrónicos fuera de las normas internacionaleshaciéndose énfasis en aspectos energéticos al determinar la potencia demandada y la energía adicional consumidadebido a la asimetría. Por último, se presenta una red neuronal cuya función es determinar el desbalance, emitirseñales de alarma y producir el disparo del sistema si fuese necesario. Para este propósito se utilizan no solo lastensiones de fase, sino las corrientes de línea y los coeficientes complejos de desbalance. Se concluye con queel desbalance es un problema energético que produce demandas y pérdidas que pueden ser cuantificadas por elcoeficiente de asimetría y el análisis estadístico. Las redes neuronales pueden ser entrenadas para ofreceralarma, protección y otras tareas en los sistemas eléctricos de potencia. También pueden ser incorporadas a lossistemas modernos de mediciones digitalizadas en los servicios industriales. Para la validación de los resultados,se emplean las mediciones recién efectuadas en una estación de bombeo del acueducto de la provincia deCienfuegos, Cuba.  There are tree goals in this article; statistical characterization of an unbalanced power system, show how longan asynchronous group of motors can be exploited out of international unbalance standards focused on powerdemand and energy consumption due to asymmetry complex defined factor and to present an artificial neuralnetwork used to send warning signals or to protect the motors under abnormal unbalanced conditions. As a case,a water supply station in Cienfuegos`s province is presented.sequence and the possibilities that this designpresents for the increase of the security of the installationI.

  1. Encoding of natural and artificial stimuli in the auditory midbrain

    Science.gov (United States)

    Lyzwa, Dominika

    How complex acoustic stimuli are encoded in the main center of convergence in the auditory midbrain is not clear. Here, the representation of neural spiking responses to natural and artificial sounds across this subcortical structure is investigated based on neurophysiological recordings from the mammalian midbrain. Neural and stimulus correlations of neuronal pairs are analyzed with respect to the neurons' distance, and responses to different natural communication sounds are discriminated. A model which includes linear and nonlinear neural response properties of this nucleus is presented and employed to predict temporal spiking responses to new sounds. Supported by BMBF Grant 01GQ0811.

  2. Regulação em rede do ambiente de trabalho

    OpenAIRE

    Kamp, Annette; Nielsen, Klaus T.

    2009-01-01

    Este artigo trata do conceito de governança em rede como contraponto à compreensão do processo convencional, hierarquizado, de regulação no campo do ambiente de trabalho. A forma como as redes podem estimular mudanças na regulação do ambiente de trabalho é estudada em dois casos na Dinamarca. O primeiro caso se refere à alta incidência de distúrbios músculo-esqueléticos - na atividade de manuseio de pacientes - encontrados no setor saúde. A rede, desenvolvida de baixo para cima, gerou uma con...

  3. La publicidad en las redes sociales. De lo intrusivo a lo consentido

    Directory of Open Access Journals (Sweden)

    Mª Isabel de Salas Nestares

    2012-04-01

    Full Text Available Con el desarrollo de las redes sociales y la web 2.0 se generan nuevas posibilidades de comunicación publicitaria. Desde el punto de vista empresarial las redes sociales muestran un mundo donde el conocimiento, el poder y la capacidad productiva empieza a estar en manos de individuos que espontáneamente se unen a partir de ciertos intereses comunes. Las redes sociales se muestran con capacidad de ser explotadas por empresas e instituciones ajenas a ellas, al insertarles publicidad en formatos adecuados y no intrusivos.

  4. Autenticación de Redes Inalámbricas usando chillispot.

    OpenAIRE

    Guevara Aulestia, David Omar

    2011-01-01

    En la actualidad conocemos, la importancia y facilidad del uso de las redes inalámbricas, estas nos permiten de una manera muy fácil tener conectividad, pero existen una serie de inconvenientes debido a no prestar atención a aspectos básicos de seguridad. Las redes inalámbricas cuentan con diferentes estándares de seguridad pero así mismo existen diferentes formas de violentar estos mecanismos que permiten un acceso no autorizado a este tipo de redes. Para asegurar la interc...

  5. Usuarios científicos y redes sociales. Recomendaciones para estar en una red social

    OpenAIRE

    Toboso, Aurora

    2012-01-01

    Las redes sociales son, hoy en día, casi omnipresentes y España ya se ha convertido en el 5º país del mundo donde más se utilizan. Antes de ponernos a abrir un perfil y publicar contenido en las diferentes redes sociales, deberíamos reflexionar primero por qué queremos estar en estas redes sociales y cuál es el objetivo que queremos conseguir. Estar en una red social es muy sencillo, lo difícil es estar con la orientación adecuada, mantener el perfil y crear conversación. Utilizamos las...

  6. Comunicaciones seguras sobre redes móviles ad hoc

    OpenAIRE

    Rocabado Moreno, Sergio Hernán; Arias Figueroa, Daniel; Sánchez, Ernesto

    2011-01-01

    En este proyecto se ha planteado investigar diferentes mecanismos para realizar comunicaciones seguras utilizando redes móviles ad-hoc, esto permitirá aprovechar las características inherentes de este tipo de redes, para llevar información crítica de forma segura a lugares donde no se disponga de acceso a redes de infraestructura. El resultado final será una propuesta que servirá de base para el desarrollo e implementación de sistemas móviles para emergencias médicas y también como material d...

  7. Proposta de metodologia para avaliação de redes de voz sobre IP

    OpenAIRE

    Vandersilvio da Silva

    2006-01-01

    A redução de custo com telefonia através do uso de voz sobre IP tem disparado a busca de soluções que transformem redes IP originalmente dedicadas a transporte de dados em redes para transporte de voz. Esta dissertação tem por objetivo apresentar uma metodologia para sistematizar a avaliação de redes para o tráfego de voz sobre IP de acordo com as possibilidades disponíveis no cenário a ser avaliado. Inicialmente é dada uma visão geral de voz sobre IP, apresentando os protocolos utilizados, o...

  8. REDES SOCIALES EN INTERNET, PATRONES DE SUEÑO Y DEPRESIÓN

    OpenAIRE

    Walter Ariel Tamayo Pérez; Francelia García Mendoza; Nayely Karina Quijano León; Alejandra Corrales Pérez; Jesús Antonio Moo Estrella

    2012-01-01

    El objetivo de este estudio fue conocer la relación entre el tiempo dedicado a las redes sociales en Internet con los hábitos de sueño y los síntomas de depresión. Participaron 120 adolescentes, con un promedio de edad de 15.32 años, de los cuales casi la mitad eran mujeres, a quienes se les aplicó un cuestionario sobre el uso de redes sociales en Internet, el Inventario de Depresión de Beck y la Escala de Somnolencia de Epworth. Los resultados indican que el tiempo dedicado a las redes soc...

  9. La enfermedad de Alzheimer desde el análisis de redes sociales

    OpenAIRE

    Llopis Cañameras, Jaume

    2015-01-01

    El estudio de las redes personales de 23 cuidadores/as de personas afectadas por la enfermedad de Alzheimer pone de manifiesto los profundos cambios que se producen en el entorno social de estas personas. En general las redes se hacen más pequeñas y se concentran en las funciones de apoyo, siguiendo varias evoluciones posibles que hemos caracterizado según una tipología: redes reducidas, institucionalizadas, medicalizadas y normalizadas. Esta tipología puede depender del estado de evolución d...

  10. Diferencias entre usuarios y no usuarios de redes sociales virtuales en la Web 2.0

    OpenAIRE

    María Alarcón; Carlota Lorenzo

    2012-01-01

    La Web 2.0 ha supuesto una revolución en el mundo de las redes digitales, debido al papel activo de los usuarios en aportar contenidos y conocimientos. En este nuevo entorno de Internet surgen las redes sociales virtuales (RSV), principal medio de comunicación online, que ofrecen múltiples ventajas para el mundo empresarial, que con el fin de obtener máxima rentabilidad, se ven obligadas a utilizar las redes para conocer mejor a los usuarios que participan en ellas. Este trabajo refleja el re...

  11. Comunicación comercial del turismo en las redes sociales

    OpenAIRE

    Fernández Sánchez, César

    2016-01-01

    RESUMEN: A lo largo de este proyecto se va hablar sobre la comunicación comercial en las redes sociales, concretamente en el sector turístico de las aerolíneas. Se empezará hablando sobre los diferentes usos de las redes sociales, destacando las ventajas y desventajas dentro de las empresas, así como los malos usos que se pueden dar en ellos, si no se usan de forma correcta. Se analizará las principales y diferentes redes sociales que existen, destacando sus características principale...

  12. Comparativa de herramientas de simulación de redes sociales

    OpenAIRE

    Camino García, Ana María

    2016-01-01

    Hoy en día, el Análisis de Redes Sociales (ARS) es muy útil, ya que refleja el comportamiento de la sociedad actual. Entre las diferentes técnicas para analizar las redes sociales, hay un interés creciente en el modelado basado en agentes (MBA), ya que permite realizar simulaciones de sistemas complejos. Por lo tanto, las herramientas de simulación cobran gran importancia para el análisis de redes sociales. En este trabajo, se analizan diferentes tipos de herramientas de simulación, con el fi...

  13. El uso de las redes sociales en los diferentes niveles formativos en España

    OpenAIRE

    Fernández-Sáenz, Patricia

    2013-01-01

    En este trabajo se pretende investigar cuáles son las redes sociales más utilizadas por los jóvenes de las diferentes edades y niveles educativos, para después poder integrarlas en el proceso de enseñanza-aprendizaje. También se quiere conocer que redes sociales utilizan los profesores en el desarrollo de sus clases. Mediante el modelo de aceptación tecnológica (TAM) se va a valorar la aceptabilidad por parte de los alumnos y los profesores de las redes sociales en los entornos educativos....

  14. Simulador y diseñador de redes informáticas

    OpenAIRE

    Salmerón Díaz, Juan Transito

    2008-01-01

    El proyecto desarrollo de un diseñador y simulador de redes informáticas, para su implementación como herramienta didáctica en la materia de redes informáticas, tuvo sus inicios por la necesidad de dotar a los docentes de la Regional San Miguel, de una herramienta didáctica adicional, para simular pruebas sobre aspectos básicos de networking y a los alumnos, permitir desarrollar análisis de estructuras y costeos de redes, sin necesidad de implementar una red físicamente.

  15. Las Redes Sociales de Internet, ¿Una nueva adicción?

    OpenAIRE

    Prieto Gutiérrez, Juan José; Moreno Cámara, Alicia

    2015-01-01

    El uso de las redes sociales a través de dispositivos conectados a Internet, tanto fijos como móviles, se encuentra en un estado de explosión global, hasta tal punto que el comportamiento de los usuarios está suscitando ciertas preocupaciones en la comunidad de salud mental. El artículo manifiesta el poder de atracción que poseen las redes sociales y sus consecuencias. Con el fin de aminorar e incluso suprimir los trastornos que ocasiona el mal empleo de las redes sociales se ofrecen unas rec...

  16. David Hume e as Paixões Indiretas na Sociedade em Rede

    Directory of Open Access Journals (Sweden)

    Tiago Porto

    2017-02-01

    Full Text Available O presente artigo pretende trazer à discussão a importância da Teoria das Paixões desenvolvida por David Hume como um horizonte interpretativo para as ações dos indivíduos conetados às redes sociais da Internet. Para tanto, este trabalho abordará inicialmente o que conhecemos por sociedade em rede e o importante papel desempenhado pela Internet nessa configuração social; em seguida, analisaremos como as paixões indiretas influenciam os indivíduos conectados à rede internacional de computadores

  17. Migrantes culiacanenses en California: Diversidad en sus redes migratorias

    Directory of Open Access Journals (Sweden)

    Ernesto SÁNCHEZ SÁNCHEZ

    2012-01-01

    Full Text Available Es un hecho la dinámica extraordinaria que tienen los lugares de reciente migración, ya sea como lugares de origen o destino. El estado de Sinaloa se suma a esta dinámica en la cual aparecen ahora sus tres principales zonas urbanas --Culiacán, Mazatlán y Ahome-- dentro de su mapa migratorio. Sin embargo la migración, como proceso social, implica una serie de interrelaciones formadas tiempo atrás. Éstas repercuten en la conformación de las nuevas redes migratorias. No obstante, durante décadas, las principales zonas de expulsión en Sinaloa han sido rurales y siguen teniendo un papel esencial en las actuales relaciones sociales de los migrantes provenientes de Culiacán.

  18. Causas "fracas" e redes causais complexas em psiquiatria

    Directory of Open Access Journals (Sweden)

    Luís Fernando S. C. de Araújo

    2014-03-01

    Full Text Available OBJETIVOS: Realizamos uma análise do conceito de causalidade aplicado em psiquiatria e propomos sua abordagem baseada nas ideias de influências causais fracas e de redes causais complexas. MÉTODO: Análise conceitual de artigos e livros selecionados. RESULTADOS: Identificamos o modelo de causalidade INUS, proposto pelo filósofo J. L. Mackie que contorna algumas das dificuldades relacionadas à presença de múltiplas causas interdependentes, como parece ocorrer no caso dos transtornos mentais e mostramos que tal modelo se aplica bem ao TEPT. CONCLUSÃO: Sugerimos que o fracasso na busca de causas "fortes" para os transtornos mentais talvez indique a necessidade de revisão de nossas expectativas, com a adoção de modelos alternativos de causalidade.

  19. Sistemas de Inteligencia Web basados en Redes Sociales

    Directory of Open Access Journals (Sweden)

    de la Rosa Troyano, Fco. Fernando

    2007-06-01

    Full Text Available Social Network Analysis (SNA is an emerging area, essential in decision making processes. Its capacities to analyze and intervene in a social network can be used to implant surveillance tasks in research centers or technological-based businesses. The aim of this work is to make a proposal to design intelligence web systems based on social networks. The first obstacle to implant these systems is the data gather process. In order to solve this problem, an extracting social networks methodology is presented. The extraction process is carried out by analyzing the search engine results. Queries are based on electronic mails. From the extracted network, its spatial distribution of social relationships, the global thematic impact and the institutional relationships are also analyzed. The social structure of REDES email distribution list is analyzed as an example.

  20. Internet y redes sociales: un nuevo contexto para el delito

    Directory of Open Access Journals (Sweden)

    M. José Pifarré

    2013-06-01

    Full Text Available Internet y, de manera muy especial, las redes sociales conforman un nuevo contexto social caracterizado, entre otras cosas, porque el alcance temporal y espacial de las comunicaciones a través de ellos crea proximidades «virtuales» antaño imposibles que han cambiado el modo en que nos relacionamos en sociedad. En este contexto, con sus particularidades y especificidades, han surgido conductas hasta ahora inéditas y ha tenido lugar una importante mutación de las convenciones sociales. La rapidez con que los comportamientos sociales cambian a causa de Internet, o con que nacen nuevas realidades en su seno, tiene pocos precedentes.

  1. Las redes sociales virtuales como espacios de ocio digital

    Directory of Open Access Journals (Sweden)

    Ana VIÑALS BLANCO

    2014-10-01

    Full Text Available Vivimos en una sociedad digital donde los hábitos y estilos de vida se han visto transformados debido al desarrollo de Internet y las nuevas Tecnologías de la Información y la Comunicación (TIC. El ocio, entendido en este artículo como experiencia de desarrollo humano (Cuenca, 2000 y ámbito vital, tampoco se ha resistido a la influencia de la tecnología y la esfera virtual, dando pie a la generación de nuevos ocios virtuales entre los que destaca el uso de las redes sociales. Son parte de las nuevas prácticas de ocio de los jóvenes españoles y los nuevos formatos de entretenimiento. Fundamentándonos en el modo de entender el ocio del Instituto de Estudios de ocio de la Universidad de Deusto y en la dicotomía de ocio serio y ocio casual defendida por Stebbins (2008, pretendemos dar respuesta a los siguientes planteamientos: ¿de qué manera ha influido la revolución digital en el ámbito del ocio?, ¿nos encontramos ante nuevos formatos de entretenimiento de carácter consumista o bien ante prácticas de ocio digital que fomentan el desarrollo personal? Esto nos llevará a analizar los usos que los jóvenes pertenecientes a la generación digital hacen de las redes sociales virtuales.

  2. Estrategia de seguridad contra ataques internos en redes locales

    Directory of Open Access Journals (Sweden)

    Andrés Subert Semanat

    2010-09-01

    Full Text Available Normal 0 21 false false false ES-TRAD X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} A pesar de las topologías de seguridad de redes basadas  en  Cortafuegos,  Enrutadores  y  Conmutadores es posible romper la seguridad interna de las redes y realizar ataques de suplantación de identidades de equipos y de usuarios. El envenenamiento de la tabla  del Protocolo de Resolución de direcciones es uno de los ataque interno mas efectivos En este trabajo se discuten y comparan tres topologías  de  red  según  las  cuales  se  puede  segmentar y aislar las vulnerabilidades encontradas en una red local, las variantes de solución  demuestran ser  efectivas  en  entornos  académicos, donde  la mayoría de las violaciones de seguridad provienen de empleados internos.

  3. Sistemas fotovoltaicos conectados à rede para Moçambique

    Directory of Open Access Journals (Sweden)

    Marcos Herbert Smith dos Santos

    2013-12-01

    Full Text Available A energia solar fotovoltaica é uma fonte limpa e importante opção como fonte alternativa de energia elétrica. Um estudo das condições energéticas de Moçambique, na África, através do ministério de energia, daquele governo, fornece dados importantes para conhecimento das condições de suas regiões desprovidas de energia elétrica. Os dados solarimétricos são usados para se definir um sistema fotovoltaico. Estes podem ser obtidos do órgão meteorológico da região, que fornece dados para as cidades das estações meteorológicas espalhadas pelo país e de laboratórios de pesquisa internacionais de campo que fornecem dados solarimétricos, usando satélites de varredura, que são capazes de cobrir todo globo terrestre e disponibilizarem aplicativos que permitem, através das coordenadas do local, identificar exatamente a irradiação solar em qualquer ponto. Neste estudo, dados laboratoriais, validados através de comparações com os dados de órgãos oficiais da região, permitiram se montar um banco de dados solarimétricos e se calcular o potencial fotovoltaico de geração de energia de cada local. Foram também observadas regiões, desprovidas de redes elétricas, muito propícias ao aproveitamento da energia solar para geração direta de eletricidade, para ser conectada à rede de distribuição.

  4. Redes de transporte ferroviario metropolitano en Andalucía

    Directory of Open Access Journals (Sweden)

    Antonio Gavira Narváez

    2011-12-01

    Full Text Available REVISTA DE ESTUDIOS ANDALUCES (REA Ayuda de la revista USUARIO/A Nombre de usuario/a Contraseña •••••••••• No cerrar sesión Iniciar sesión NOTIFICACIONES Ver Suscribirse IDIOMA CONTENIDO DE LA REVISTA Buscar Buscar Examinar Por número Por autor/a Por título Otras revistas Categorías TAMAÑO DE FUENTE Make font size smallerMake font size defaultMake font size larger INFORMACIÓN Para los lectores/as Para los autores/as Para los bibliotecarios/as INICIO ACERCA DE INICIAR SESIÓN REGISTRARSE CATEGORÍAS BUSCAR ACTUAL ARCHIVOS AVISOS Inicio > Vol. 28, núm. 1 (2011 >\tGavira-Narváez Redes de transporte ferroviario metropolitano en Andalucía. Antonio Gavira-Narváez Resumen En los últimos años se han emprendido diversas mejoras en las redes ferroviarias de transporte metropolitano (Cercanías, metro y tranvía que han propiciado un incremento del número de viajeros, así como la adecuación de los servicios para que puedan tener acceso un mayor número de habitantes. Estas actuaciones han favorecido una reducción del uso del automóvil, así como menores afecciones al clima de las poblaciones que se han beneficiado de su puesta en funcionamiento. El desarrollo de estos servicios de transporte son fundamentales en la situación socioeconómica actual, pues favorece la movilidad de colectivos que no tienen acceso a medios de transporte privado. Asimismo, la oportuna implantación ha acarreado que muchos de estos servicios sean más competitivos con respecto al resto de medios de transporte en calidad y precio, lo que potencia su competitividad.

  5. Microfluidic Neurons, a New Way in Neuromorphic Engineering?

    Directory of Open Access Journals (Sweden)

    Timothée Levi

    2016-08-01

    Full Text Available This article describes a new way to explore neuromorphic engineering, the biomimetic artificial neuron using microfluidic techniques. This new device could replace silicon neurons and solve the issues of biocompatibility and power consumption. The biological neuron transmits electrical signals based on ion flow through their plasma membrane. Action potentials are propagated along axons and represent the fundamental electrical signals by which information are transmitted from one place to another in the nervous system. Based on this physiological behavior, we propose a microfluidic structure composed of chambers representing the intra and extracellular environments, connected by channels actuated by Quake valves. These channels are equipped with selective ion permeable membranes to mimic the exchange of chemical species found in the biological neuron. A thick polydimethylsiloxane (PDMS membrane is used to create the Quake valve membrane. Integrated electrodes are used to measure the potential difference between the intracellular and extracellular environments: the membrane potential.

  6. REDES PERSONALES Y DIMENSIONES DE APOYO EN INDIVIDUOS DESMOVILIZADOS DEL CONFLICTO ARMADO

    Directory of Open Access Journals (Sweden)

    José Hernando Ávila-Toscano

    2010-01-01

    Full Text Available El objetivo de este estudio fue identificar las características de las redes personales de un grupo de individuos desmovilizados del conflicto armado colombiano. Se evaluaron diez hombres mediante un diseño descriptivo transversal de enfoque cuantitativo con la aplicación del ASSIS para medir las redes y se identificaron seis dimensiones de apoyo social. Las redes personales se visualizaron con el programa Visone 2.3.5, y se detectó que la ayuda material es la dimensión de mayor satisfacción en la muestra. Sobresalen las redes pequeñas, conformadas por familiares y con buen nivel de intimidad personal.

  7. La comunicación de los jóvenes adolescentes en las redes sociales

    Directory of Open Access Journals (Sweden)

    Javier Callejo Gallego

    2014-11-01

    Full Text Available Este artículo presenta los resultados de un estudio empírico cualitativo sobre el uso de las redes sociales en Internet, realizado en Madrid entre jóvenes y adolescentes. Se plantea y discute la tesis que entiende las redes sociales digitales como un artefacto para generar comunicación dialógica. Por lo tanto, se pone entre paréntesis el carácter discursivo de las redes sociales y su forma comunicacional centrada en el relato como forma expresiva, y como tradicional objeto de análisis. Observando lo que hacen los jóvenes adolescentes en este espacio para la comunicación, se concluye que las redes sociales digitales tienen su propia forma de interacción social, modificando sustancialmente el sentido e interés relacional que imponen formalmente a los sujetos que las emplean.

  8. Presencia y aplicación de las redes sociales en el contexto educativo

    OpenAIRE

    Rodríguez López, Pedro Alfonso

    2015-01-01

    Se pretende describir la presencia de las redes sociales en la práctica educativa de un grupo de profesores de Educación Secundaria Obligatoria que imparte docencia en un centro educativo concertado

  9. ANÁLISE E GERENCIAMENTO DE REDES USANDO UMA METODOLOGIA PROATIVA COM ZABBIX

    Directory of Open Access Journals (Sweden)

    Wanderson Michel Silva

    2016-01-01

    Full Text Available Diante do crescimento de empresas que adotam a tecnologia da informação como ferramenta estratégica e de controle, o gerenciamento de redes surge como necessidade em um ambiente que o número de dispositivos de redes aumenta com o decorrer do tempo. Visando a centralização da gerência de redes e o baixo custo para implementação, esse artigo propõe a utilização da ferramenta Zabbix e do protocolo SNMP, não somente para monitoramento e controle, mas para resolução e antecipação de problemas relacionados a equipamentos de rede.

  10. Las redes del narcotráfico y sus interacciones: un modelo teórico

    Directory of Open Access Journals (Sweden)

    Leonardo Raffo López

    2015-06-01

    Full Text Available En este artículo se propone un modelo teórico que ayuda a entender el funcionamiento de las redes de defensa y corrupción del narcotráfico. Con base en las teorías de juegos y de redes se analizan las interacciones estratégicas entre los narcotraficantes y sus agentes. Se prueba que la densidad de las redes es un determinante fundamental de la probabilidad de supervivencia de los narcotraficantes y de los salarios que pagan a sus hombres; y que la eficacia de las políticas de represión de la oferta depende de la densidad de las redes.

  11. Artificial intelligence in nanotechnology.

    Science.gov (United States)

    Sacha, G M; Varona, P

    2013-11-15

    During the last decade there has been increasing use of artificial intelligence tools in nanotechnology research. In this paper we review some of these efforts in the context of interpreting scanning probe microscopy, the study of biological nanosystems, the classification of material properties at the nanoscale, theoretical approaches and simulations in nanoscience, and generally in the design of nanodevices. Current trends and future perspectives in the development of nanocomputing hardware that can boost artificial-intelligence-based applications are also discussed. Convergence between artificial intelligence and nanotechnology can shape the path for many technological developments in the field of information sciences that will rely on new computer architectures and data representations, hybrid technologies that use biological entities and nanotechnological devices, bioengineering, neuroscience and a large variety of related disciplines.

  12. Artificial organ engineering

    CERN Document Server

    Annesini, Maria Cristina; Piemonte, Vincenzo; Turchetti, Luca

    2017-01-01

    Artificial organs may be considered as small-scale process plants, in which heat, mass and momentum transfer operations and, possibly, chemical transformations are carried out. This book proposes a novel analysis of artificial organs based on the typical bottom-up approach used in process engineering. Starting from a description of the fundamental physico-chemical phenomena involved in the process, the whole system is rebuilt as an interconnected ensemble of elemental unit operations. Each artificial organ is presented with a short introduction provided by expert clinicians. Devices commonly used in clinical practice are reviewed and their performance is assessed and compared by using a mathematical model based approach. Whilst mathematical modelling is a fundamental tool for quantitative descriptions of clinical devices, models are kept simple to remain focused on the essential features of each process. Postgraduate students and researchers in the field of chemical and biomedical engineering will find that t...

  13. Artificial intelligence in nanotechnology

    Science.gov (United States)

    Sacha, G. M.; Varona, P.

    2013-11-01

    During the last decade there has been increasing use of artificial intelligence tools in nanotechnology research. In this paper we review some of these efforts in the context of interpreting scanning probe microscopy, the study of biological nanosystems, the classification of material properties at the nanoscale, theoretical approaches and simulations in nanoscience, and generally in the design of nanodevices. Current trends and future perspectives in the development of nanocomputing hardware that can boost artificial-intelligence-based applications are also discussed. Convergence between artificial intelligence and nanotechnology can shape the path for many technological developments in the field of information sciences that will rely on new computer architectures and data representations, hybrid technologies that use biological entities and nanotechnological devices, bioengineering, neuroscience and a large variety of related disciplines.

  14. Artificial organs and transplantation.

    Science.gov (United States)

    Splendiani, G; Cipriani, S; Vega, A; Casciani, C U

    2003-05-01

    Nowadays artificial devices are not able to totally and undefinitely replace the loss of function of all vital organs and artificial organs can be used only to bridge the time to transplantation, which must be considered the first choice in the therapeutical approach for many chronic diseases. Since general population aging process is leading to an increase of organ demand, the gap between performed and requested transplantation is hard to fill. Xenotransplantation is nowadays only an experimental alternative solution and we have to do our best using available artificial organs to increase and improve the survival of patients waiting for transplantation. In this meeting we particularly dealt about organ function replacing therapy, especially regarding the kidney, heart, liver, pancreas and ear.

  15. Charlas sobre inteligencia artificial

    OpenAIRE

    Álvarez Sánchez, José Ramón; Ferrández Vicente, José Manuel; Paz López, Félix de la

    2014-01-01

    Serie: Informática en Radio 3 La Inteligencia Artificial es una de las ciencias que causa mayor impacto en la sociedad, mucho más si tenemos en cuenta que cambiará el futuro de la humanidad. En España existen actualmente un nutrido grupo de equipos de investigación relacionados con las tecnologías de computación natural-artificial que aúnan sus esfuerzos a través de la RTNAC la Red Temática en Tecnologías de Computación Natural-Artificial . La UNED participa en todas sus actividades desde ...

  16. Artificial Intelligence in Cardiology.

    Science.gov (United States)

    Johnson, Kipp W; Torres Soto, Jessica; Glicksberg, Benjamin S; Shameer, Khader; Miotto, Riccardo; Ali, Mohsin; Ashley, Euan; Dudley, Joel T

    2018-06-12

    Artificial intelligence and machine learning are poised to influence nearly every aspect of the human condition, and cardiology is not an exception to this trend. This paper provides a guide for clinicians on relevant aspects of artificial intelligence and machine learning, reviews selected applications of these methods in cardiology to date, and identifies how cardiovascular medicine could incorporate artificial intelligence in the future. In particular, the paper first reviews predictive modeling concepts relevant to cardiology such as feature selection and frequent pitfalls such as improper dichotomization. Second, it discusses common algorithms used in supervised learning and reviews selected applications in cardiology and related disciplines. Third, it describes the advent of deep learning and related methods collectively called unsupervised learning, provides contextual examples both in general medicine and in cardiovascular medicine, and then explains how these methods could be applied to enable precision cardiology and improve patient outcomes. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  17. Artificial intelligence in nanotechnology

    International Nuclear Information System (INIS)

    Sacha, G M; Varona, P

    2013-01-01

    During the last decade there has been increasing use of artificial intelligence tools in nanotechnology research. In this paper we review some of these efforts in the context of interpreting scanning probe microscopy, the study of biological nanosystems, the classification of material properties at the nanoscale, theoretical approaches and simulations in nanoscience, and generally in the design of nanodevices. Current trends and future perspectives in the development of nanocomputing hardware that can boost artificial-intelligence-based applications are also discussed. Convergence between artificial intelligence and nanotechnology can shape the path for many technological developments in the field of information sciences that will rely on new computer architectures and data representations, hybrid technologies that use biological entities and nanotechnological devices, bioengineering, neuroscience and a large variety of related disciplines. (topical review)

  18. Teoría de precios de arbitraje. Evidencia empírica para Colombia a través de redes neuronales

    Directory of Open Access Journals (Sweden)

    Charle Londoño

    2011-07-01

    Full Text Available Esta investigación utiliza una red neuronal multicapa para relacionar el Índice General de Bolsa de Valores de Colombia (IGBC con fundamentales macroeconómicos y variables financieras. Proponemos dos modelos: un modelo APT (fundamentales macroeconómicos y un modelo APT modificado (fundamentales macroeconómicos + indicador de las bolsas del mundo; de acuerdo a nuestro análisis el APT tradicional se ajusta mejor para predecir el mercado de valores Colombiano. Los resultados confirman que las redes neuronales artificiales (ANN son más efectivas que los modelos estadísticos tradicionales por su capacidad explicativa y precisión.

  19. El impacto de las redes sociales en la función consumo

    OpenAIRE

    Jiménez Nieto, Sara; Jiménez Ruiz, Cristian Camilo

    2013-01-01

    El trabajo evalúa el impacto de las redes sociales en el volumen de ventas en el mercado de consumo masivo directo B2C (Business to consumer), medido a través de la manera en que las redes sociales afectan las preferencias del consumidor y por esta vía su función de consumo en la población

  20. Artificial intelligence executive summary

    International Nuclear Information System (INIS)

    Wamsley, S.J.; Purvis, E.E. III

    1984-01-01

    Artificial intelligence (AI) is a high technology field that can be used to provide problem solving diagnosis, guidance and for support resolution of problems. It is not a stand alone discipline, but can also be applied to develop data bases for retention of the expertise that is required for its own knowledge base. This provides a way to retain knowledge that otherwise may be lost. Artificial Intelligence Methodology can provide an automated construction management decision support system, thereby restoring the manager's emphasis to project management

  1. Artificial intelligence in cardiology.

    Science.gov (United States)

    Bonderman, Diana

    2017-12-01

    Decision-making is complex in modern medicine and should ideally be based on available data, structured knowledge and proper interpretation in the context of an individual patient. Automated algorithms, also termed artificial intelligence that are able to extract meaningful patterns from data collections and build decisions upon identified patterns may be useful assistants in clinical decision-making processes. In this article, artificial intelligence-based studies in clinical cardiology are reviewed. The text also touches on the ethical issues and speculates on the future roles of automated algorithms versus clinicians in cardiology and medicine in general.

  2. Spatially Resolved Artificial Chemistry

    DEFF Research Database (Denmark)

    Fellermann, Harold

    2009-01-01

    Although spatial structures can play a crucial role in chemical systems and can drastically alter the outcome of reactions, the traditional framework of artificial chemistry is a well-stirred tank reactor with no spatial representation in mind. Advanced method development in physical chemistry has...... made a class of models accessible to the realms of artificial chemistry that represent reacting molecules in a coarse-grained fashion in continuous space. This chapter introduces the mathematical models of Brownian dynamics (BD) and dissipative particle dynamics (DPD) for molecular motion and reaction...

  3. Bayesian artificial intelligence

    CERN Document Server

    Korb, Kevin B

    2003-01-01

    As the power of Bayesian techniques has become more fully realized, the field of artificial intelligence has embraced Bayesian methodology and integrated it to the point where an introduction to Bayesian techniques is now a core course in many computer science programs. Unlike other books on the subject, Bayesian Artificial Intelligence keeps mathematical detail to a minimum and covers a broad range of topics. The authors integrate all of Bayesian net technology and learning Bayesian net technology and apply them both to knowledge engineering. They emphasize understanding and intuition but also provide the algorithms and technical background needed for applications. Software, exercises, and solutions are available on the authors' website.

  4. Spatially Resolved Artificial Chemistry

    DEFF Research Database (Denmark)

    Fellermann, Harold

    2009-01-01

    made a class of models accessible to the realms of artificial chemistry that represent reacting molecules in a coarse-grained fashion in continuous space. This chapter introduces the mathematical models of Brownian dynamics (BD) and dissipative particle dynamics (DPD) for molecular motion and reaction......Although spatial structures can play a crucial role in chemical systems and can drastically alter the outcome of reactions, the traditional framework of artificial chemistry is a well-stirred tank reactor with no spatial representation in mind. Advanced method development in physical chemistry has...

  5. Evaluación de medidas técnicas introducidas en las redes del litoral de Ciudad de La Habana. Parte I

    Directory of Open Access Journals (Sweden)

    Olga Susana Suárez

    2011-10-01

    Full Text Available En el trabajo se reportan los primeros resultados alcanzados en la evaluación de las medidas técnicas introducidas en las redes del litoral de Ciudad de la Habana en el proceso de rehabilitación de las redes de distribución que tiene lugar dentro de la Revolución Energética. Estas medidas fueron, principalmente, la sustitución de aisladores deporcelana por poliméricos y el cambio de las crucetas de maderas por crucetas de hierro. En esta primera parte, los resultados de un exhaustivo ciclo de ensayos de laboratorio de los parámetros eléctricos del aislador polimérico ISOELECTRIC, ciclos de ensayos de contaminación natural y contaminación artificial así como los resultados de la inspección de campo después de entre 3 y 6 meses de instalación permiten recomendar la suspensión de la instalación de este tipo de aisladores en el litoral habanero y realizar un estricto control de los ya instalados paraevitar situaciones complejas de operación. In this paper are reported the first achieved results in relation to the technical procedures applied in the littoral distribution network of Havana City in the process of distribution network rehabilitation that takes place inside the Energetic Revolution. These procedures were mainly the substitution of the porcelain for polymeric insulator. In thisfirst part, the results of the an exhaustive laboratorial test cycles of the electric parameters of ISOELECTRIC polymeric insulator, natural and artificial contamination test cycles, as well as visual inspection results after three and six moths of installation, have allowed to suggest the suspension of the installation of this type of insulators in thiszone and to carry out a strict control of those previously installed in order to avoid complex situations of operation.

  6. Kappe neurons, a novel population of olfactory sensory neurons

    OpenAIRE

    Ahuja, Gaurav; Nia, Shahrzad Bozorg; Zapilko, Veronika; Shiriagin, Vladimir; Kowatschew, Daniel; Oka, Yuichiro; Korsching, Sigrun I.

    2014-01-01

    Perception of olfactory stimuli is mediated by distinct populations of olfactory sensory neurons, each with a characteristic set of morphological as well as functional parameters. Beyond two large populations of ciliated and microvillous neurons, a third population, crypt neurons, has been identified in teleost and cartilaginous fishes. We report here a novel, fourth olfactory sensory neuron population in zebrafish, which we named kappe neurons for their characteristic shape. Kappe neurons ar...

  7. Prediction of Availability Indicator of Water Pipes Using Artificial Intelligence

    Directory of Open Access Journals (Sweden)

    Kutyłowska Małgorzata

    2017-01-01

    Full Text Available The paper presents the results of artificial neural networks application to the availability indicator prediction. The forecasted results indicate that artificial networks may be used to model the reliability level of the water supply systems. The network was trained using 147 and 173 operational data from one Polish medium-sized city (distribution pipes and house connections, respectively. 50% of all data was chosen for learning, 25% for testing and 25% for validation. In prognosis phase, the best created network used 100% of 114 and 133 values for testing. Following functions were used to activate neurons in hidden and output layers: linear, logistic, hyperbolic tangent, exponential. The learning of the artificial network was performed using following input parameters: material, total length, diameter. In the optimal models hyperbolic tangent was chosen to activate the hidden and output neurons in modeling the availability indicator of house connections during 68 epochs of training. Hidden and output neurons were activated (20 epochs of learning respectively by hyperbolic tangent and linear function during the prediction of availability indicator of distribution pipes. The maximum relative errors in learning and prognosis step were equal to 0.10% and 1.20% as well as 0.27% and 1.15% for distribution pipes and house connections, respectively.

  8. Redes y apoyo social en ancianos enfermos de escasos recursos en Guadalajara, México

    Directory of Open Access Journals (Sweden)

    Robles Leticia

    2000-01-01

    Full Text Available El objetivo de este trabajo es analizar la composición de las redes y el apoyo social de ancianos enfermos de escasos recursos en Guadalajara, México. Se entrevistaron a 40 ancianos durante su hospitalización con un cuestionario de preguntas abiertas. Las redes sociales de estos ancianos están compuestas por 7,5 integrantes en promedio, principalmente mujeres, son redes multigeneracionales e incluyen a la familia extensa. Las redes en su mayoría proporcionan apoyo emocional. Las ancianas tienen redes más grandes y reciben más apoyo social en comparación a los ancianos varones; los ancianos casados y viudos, a su vez, tienen redes más grandes y reciben más apoyo social que los solteros. No hay diferencias por la edad y con quien vive en la unidad doméstica. Se requieren futuros estudios sobre los aspectos culturales y sociales sobre el tema.

  9. Redes y apoyo social en ancianos enfermos de escasos recursos en Guadalajara, México

    Directory of Open Access Journals (Sweden)

    Leticia Robles

    2000-06-01

    Full Text Available El objetivo de este trabajo es analizar la composición de las redes y el apoyo social de ancianos enfermos de escasos recursos en Guadalajara, México. Se entrevistaron a 40 ancianos durante su hospitalización con un cuestionario de preguntas abiertas. Las redes sociales de estos ancianos están compuestas por 7,5 integrantes en promedio, principalmente mujeres, son redes multigeneracionales e incluyen a la familia extensa. Las redes en su mayoría proporcionan apoyo emocional. Las ancianas tienen redes más grandes y reciben más apoyo social en comparación a los ancianos varones; los ancianos casados y viudos, a su vez, tienen redes más grandes y reciben más apoyo social que los solteros. No hay diferencias por la edad y con quien vive en la unidad doméstica. Se requieren futuros estudios sobre los aspectos culturales y sociales sobre el tema.

  10. NEURON and Python.

    Science.gov (United States)

    Hines, Michael L; Davison, Andrew P; Muller, Eilif

    2009-01-01

    The NEURON simulation program now allows Python to be used, alone or in combination with NEURON's traditional Hoc interpreter. Adding Python to NEURON has the immediate benefit of making available a very extensive suite of analysis tools written for engineering and science. It also catalyzes NEURON software development by offering users a modern programming tool that is recognized for its flexibility and power to create and maintain complex programs. At the same time, nothing is lost because all existing models written in Hoc, including graphical user interface tools, continue to work without change and are also available within the Python context. An example of the benefits of Python availability is the use of the xml module in implementing NEURON's Import3D and CellBuild tools to read MorphML and NeuroML model specifications.

  11. Generality in Artificial Intelligence

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 3. Generality in Artificial Intelligence. John McCarthy. Classics Volume 19 Issue 3 March 2014 pp 283-296. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/019/03/0283-0296. Author Affiliations.

  12. Artificial molecular motors

    NARCIS (Netherlands)

    Kassem, Salma; van Leeuwen, Thomas; Lubbe, Anouk S.; Wilson, Miriam R.; Feringa, Ben L.; Leigh, David A.

    2017-01-01

    Motor proteins are nature's solution for directing movement at the molecular level. The field of artificial molecular motors takes inspiration from these tiny but powerful machines. Although directional motion on the nanoscale performed by synthetic molecular machines is a relatively new

  13. Artificial intelligence within AFSC

    Science.gov (United States)

    Gersh, Mark A.

    1990-01-01

    Information on artificial intelligence research in the Air Force Systems Command is given in viewgraph form. Specific research that is being conducted at the Rome Air Development Center, the Space Technology Center, the Human Resources Laboratory, the Armstrong Aerospace Medical Research Laboratory, the Armamant Laboratory, and the Wright Research and Development Center is noted.

  14. Database in Artificial Intelligence.

    Science.gov (United States)

    Wilkinson, Julia

    1986-01-01

    Describes a specialist bibliographic database of literature in the field of artificial intelligence created by the Turing Institute (Glasgow, Scotland) using the BRS/Search information retrieval software. The subscription method for end-users--i.e., annual fee entitles user to unlimited access to database, document provision, and printed awareness…

  15. Spinal cord: motor neuron diseases.

    Science.gov (United States)

    Rezania, Kourosh; Roos, Raymond P

    2013-02-01

    Spinal cord motor neuron diseases affect lower motor neurons in the ventral horn. This article focuses on the most common spinal cord motor neuron disease, amyotrophic lateral sclerosis, which also affects upper motor neurons. Also discussed are other motor neuron diseases that only affect the lower motor neurons. Despite the identification of several genes associated with familial amyotrophic lateral sclerosis, the pathogenesis of this complex disease remains elusive. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Artificial skin and patient simulator comprising the artificial skin

    NARCIS (Netherlands)

    2011-01-01

    The invention relates to an artificial skin (10, 12, 14), and relates to a patient simulator (100) comprising the artificial skin. The artificial skin is a layered structure comprising a translucent cover layer (20) configured for imitating human or animal skin, and comprising a light emitting layer

  17. UTILIZAÇÃO DA METODOLOGIA GRANADOS PARA A OTIMIZAÇÃO DE REDES HIDRÁULICAS MALHADAS

    Directory of Open Access Journals (Sweden)

    Antonio Farias Leal

    Full Text Available RESUMO O método Granados de otimização, desenvolvido para redes ramificadas, foi associado à metodologia dos anéis de Hardy Cross e aplicado a redes malhadas. Os resultados obtidos mostram uma economia significativa no custo total das tubulações e revelam a potencialidade dessa ferramenta, que assume, definitivamente, o seu lugar no dimensionamento de redes pressurizadas.

  18. [Hardware Implementation of Numerical Simulation Function of Hodgkin-Huxley Model Neurons Action Potential Based on Field Programmable Gate Array].

    Science.gov (United States)

    Wang, Jinlong; Lu, Mai; Hu, Yanwen; Chen, Xiaoqiang; Pan, Qiangqiang

    2015-12-01

    Neuron is the basic unit of the biological neural system. The Hodgkin-Huxley (HH) model is one of the most realistic neuron models on the electrophysiological characteristic description of neuron. Hardware implementation of neuron could provide new research ideas to clinical treatment of spinal cord injury, bionics and artificial intelligence. Based on the HH model neuron and the DSP Builder technology, in the present study, a single HH model neuron hardware implementation was completed in Field Programmable Gate Array (FPGA). The neuron implemented in FPGA was stimulated by different types of current, the action potential response characteristics were analyzed, and the correlation coefficient between numerical simulation result and hardware implementation result were calculated. The results showed that neuronal action potential response of FPGA was highly consistent with numerical simulation result. This work lays the foundation for hardware implementation of neural network.

  19. A Subset of Serotonergic Neurons Evokes Hunger in Adult Drosophila.

    Science.gov (United States)

    Albin, Stephanie D; Kaun, Karla R; Knapp, Jon-Michael; Chung, Phuong; Heberlein, Ulrike; Simpson, Julie H

    2015-09-21

    Hunger is a complex motivational state that drives multiple behaviors. The sensation of hunger is caused by an imbalance between energy intake and expenditure. One immediate response to hunger is increased food consumption. Hunger also modulates behaviors related to food seeking such as increased locomotion and enhanced sensory sensitivity in both insects and vertebrates. In addition, hunger can promote the expression of food-associated memory. Although progress is being made, how hunger is represented in the brain and how it coordinates these behavioral responses is not fully understood in any system. Here, we use Drosophila melanogaster to identify neurons encoding hunger. We found a small group of neurons that, when activated, induced a fed fly to eat as though it were starved, suggesting that these neurons are downstream of the metabolic regulation of hunger. Artificially activating these neurons also promotes appetitive memory performance in sated flies, indicating that these neurons are not simply feeding command neurons but likely play a more general role in encoding hunger. We determined that the neurons relevant for the feeding effect are serotonergic and project broadly within the brain, suggesting a possible mechanism for how various responses to hunger are coordinated. These findings extend our understanding of the neural circuitry that drives feeding and enable future exploration of how state influences neural activity within this circuit. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Solving Constraint Satisfaction Problems with Networks of Spiking Neurons.

    Science.gov (United States)

    Jonke, Zeno; Habenschuss, Stefan; Maass, Wolfgang

    2016-01-01

    Network of neurons in the brain apply-unlike processors in our current generation of computer hardware-an event-based processing strategy, where short pulses (spikes) are emitted sparsely by neurons to signal the occurrence of an event at a particular point in time. Such spike-based computations promise to be substantially more power-efficient than traditional clocked processing schemes. However, it turns out to be surprisingly difficult to design networks of spiking neurons that can solve difficult computational problems on the level of single spikes, rather than rates of spikes. We present here a new method for designing networks of spiking neurons via an energy function. Furthermore, we show how the energy function of a network of stochastically firing neurons can be shaped in a transparent manner by composing the networks of simple stereotypical network motifs. We show that this design approach enables networks of spiking neurons to produce approximate solutions to difficult (NP-hard) constraint satisfaction problems from the domains of planning/optimization and verification/logical inference. The resulting networks employ noise as a computational resource. Nevertheless, the timing of spikes plays an essential role in their computations. Furthermore, networks of spiking neurons carry out for the Traveling Salesman Problem a more efficient stochastic search for good solutions compared with stochastic artificial neural networks (Boltzmann machines) and Gibbs sampling.

  1. Solving constraint satisfaction problems with networks of spiking neurons

    Directory of Open Access Journals (Sweden)

    Zeno eJonke

    2016-03-01

    Full Text Available Network of neurons in the brain apply – unlike processors in our current generation ofcomputer hardware – an event-based processing strategy, where short pulses (spikes areemitted sparsely by neurons to signal the occurrence of an event at a particular point intime. Such spike-based computations promise to be substantially more power-efficient thantraditional clocked processing schemes. However it turned out to be surprisingly difficult todesign networks of spiking neurons that can solve difficult computational problems on the levelof single spikes (rather than rates of spikes. We present here a new method for designingnetworks of spiking neurons via an energy function. Furthermore we show how the energyfunction of a network of stochastically firing neurons can be shaped in a quite transparentmanner by composing the networks of simple stereotypical network motifs. We show that thisdesign approach enables networks of spiking neurons to produce approximate solutions todifficult (NP-hard constraint satisfaction problems from the domains of planning/optimizationand verification/logical inference. The resulting networks employ noise as a computationalresource. Nevertheless the timing of spikes (rather than just spike rates plays an essential rolein their computations. Furthermore, networks of spiking neurons carry out for the Traveling Salesman Problem a more efficient stochastic search for good solutions compared with stochastic artificial neural networks (Boltzmann machines and Gibbs sampling.

  2. Introduction to Artificial Neural Networks

    DEFF Research Database (Denmark)

    Larsen, Jan

    1999-01-01

    The note addresses introduction to signal analysis and classification based on artificial feed-forward neural networks.......The note addresses introduction to signal analysis and classification based on artificial feed-forward neural networks....

  3. Neuronal-glial trafficking

    International Nuclear Information System (INIS)

    Bachelard, H.S.

    2001-01-01

    Full text: The name 'glia' originates from the Greek word for glue, because astro glia (or astrocytes) were thought only to provide an anatomical framework for the electrically-excitable neurones. However, awareness that astrocytes perform vital roles in protecting the neurones, which they surround, emerged from evidence that they act as neuroprotective K + -sinks, and that they remove potentially toxic extracellular glutamate from the vicinity of the neurones. The astrocytes convert the glutamate to non-toxic glutamine which is returned to the neurones and used to replenish transmitter glutamate. This 'glutamate-glutamine cycle' (established in the 1960s by Berl and his colleagues) also contributes to protecting the neurones against a build-up of toxic ammonia. Glial cells also supply the neurones with components for free-radical scavenging glutathione. Recent studies have revealed that glial cells play a more positive interactive role in furnishing the neurones with fuels. Studies using radioactive 14 C, 13 C-MRS and 15 N-GCMS have revealed that glia produce alanine, lactate and proline for consumption by neurones, with increased formation of neurotransmitter glutamate. On neuronal activation the release of NH 4 + and glutamate from the neurones stimulates glucose uptake and glycolysis in the glia to produce more alanine, which can be regarded as an 'alanine-glutamate cycle' Use of 14 C-labelled precursors provided early evidence that neurotransmitter GABA may be partly derived from glial glutamine, and this has been confirmed recently in vivo by MRS isotopomer analysis of the GABA and glutamine labelled from 13 C-acetate. Relative rates of intermediary metabolism in glia and neurones can be calculated using a combination of [1- 13 C] glucose and [1,2- 13 C] acetate. When glutamate is released by neurones there is a net neuronal loss of TCA intermediates which have to be replenished. Part of this is derived from carboxylation of pyruvate, (pyruvate carboxylase

  4. Tipos de redes personales de los inmigrantes y adaptación psicológica.

    Directory of Open Access Journals (Sweden)

    Maya Jariego, Isidro

    2002-01-01

    Full Text Available Elaboramos una tipología de redes de apoyo en un colectivo de inmigrantes marroquíes (n=81, filipinos (n=69 y senegaleses (n=23 residentes en Marbella, aplicando la entrevista Mannheim de apoyo social (MISS (Veiel, 1990, 1993. Primero realizamos tres análisis de conglomerados exploratorios utilizando como variables-criterio indicadores de (1 composición familiar y étnica, (2 funciones de apoyo, y (3 tamaño y estructura de la red. Los análisis de chi-cuadrado entre las tres clasificaciones revelaron la solución de cinco clusters como la más apropiada. Para elaborar una tipología global con cinco categorías, seleccionamos siete indicadores de la red de apoyo, tomando en consideración para elegir cada variable: la diferenciación entre clusters, la saturación en una solución factorial y la matriz de correlaciones. Las variables-criterio seleccionadas fueron: disponibilidad de apoyo cotidiano psicológico, disponibilidad de apoyo instrumental en situaciones de crisis, número de compatriotas en la red de apoyo, número de españoles en la red de apoyo, número de familiares en la red de apoyo, número de no-familiares en la red de apoyo, y multiplicidad media de los vínculos. Los cinco clusters resultantes fueron (1 redes pequeñas de amigos y familiares compatriotas, (2 redes étnicas con predominio de vínculos especializados, (3 redes sinérgicas con predominio de amigos compatriotas, (4 redes étnicas de reagrupamiento familiar, y (5 redes de reagrupamiento familiar integradas en la comunidad receptora. Los tres colectivos estudiados tienen un perfil claramente diferenciado en sus redes personales: el 60% de los marroquíes se ubica en la categoría de redes más pequeñas, y el 60% de los senegaleses pertenece a grupos de compatriotas polivalentes. Por último, la tipología distingue significativamente los niveles de bienestar psicológico y el grado de utilización de servicios sociales. Los inmigrantes con redes peque

  5. ANÁLISIS DE REDES SOCIALES COMO POSIBILIDAD TEÓRICO-METODOLÓGICA PARA LA INVESTIGACIÓN EDUCATIVA

    OpenAIRE

    Luis Carlos Morales Zúñiga

    2011-01-01

    El artículo tiene como principal objetivo sugerir la utilización de la Teoría de Redes Sociales para la investigación educativa. Para ello, inicialmente se señala el origen y la definición de la Teoría de Redes Sociales; después, se presentan tres ejemplos de análisis de redes sociales en la investigación social. Por último, se proponen algunos lineamientos para utilizar la Teoría de Redes Sociales en la investigación educativa.

  6. Internacionalização das redes de franquias brasileiras: uma análise organizacional e institucional

    OpenAIRE

    Pedro Lucas de Resende Melo

    2012-01-01

    Mesmo que apenas 4,7% das redes de franquias brasileiras atuem internacionalmente, na última década o processo de internacionalização das redes de franquias brasileiras apresentou um crescimento de 300%. Existem atualmente cerca 70 redes de franquias brasileiras em operação em todos os continentes, representando cerca de 49 países, constituindo mais de 700 unidades franqueadas. Esta tese realizou uma análise organizacional e institucional envolvendo as redes de franquias brasileiras com opera...

  7. Modelo de agente racional para auxiliar na gestão de serviços em redes de computadores

    OpenAIRE

    José Elias da Silva Justo; Annabell del Real Tamariz

    2012-01-01

    A globalização aumentou consideravelmente o volume de dados a serem processados, surgindo a necessidade de interligar computadores em redes. Administrar redes de computadores não é uma tarefa trivial. Agentes inteligentes podem auxiliar na gestão de redes de computadores. O objetivo deste trabalho é desenvolver um protótipo baseado em um agente de software, que monitore, gerencie serviços prestados em redes de computadores e intervenha reativamente, reiniciando quaisquer dos serviços com prob...

  8. Criminal Aspects of Artificial Abortion

    OpenAIRE

    Hartmanová, Leona

    2016-01-01

    Criminal Aspects of Artificial Abortion This diploma thesis deals with the issue of artificial abortion, especially its criminal aspects. Legal aspects are not the most important aspects of artificial abortion. Social, ethical or ideological aspects are of the same importance but this diploma thesis cannot analyse all of them. The main issue with artificial abortion is whether it is possible to force a pregnant woman to carry a child and give birth to a child when she cannot or does not want ...

  9. Las redes sociales de la economía social

    Directory of Open Access Journals (Sweden)

    Paula Escribano

    2014-12-01

    Full Text Available A partir del trabajo de campo en curso llevado a cabo en Cataluña (proyecto de investigación ENCLAVE - CSO2012-32635, se sugiere la existencia de al menos tres tipos de los llamados "empresarios sociales": los profesionales desplazados por los recortes en el gasto público en los sectores de la salud, los servicios sociales y la cooperación; las cooperativas y las asociaciones tradicionales, re-etiquetados como "empresarios sociales" o "empresas sociales" (conversos y, por último, los que gozan de apoyo institucional público y privado para el desarrollo de sus iniciativas sociales o ambientales (elegidos. Con el fin de contrastar algunas de las hipótesis que plantea la literatura sobre los emprendedores sociales (a saber, su capacidad para movilizar recursos locales y lograr la participación de una amplia gama de actores para el logro de sus fines, se recogieron redes personales de casos de emprendedores sociales con la ayuda de EgoNet (http:// sourceforge.net/projects/egonet utilizando un generador múltiple de nombres para obtener datos sobre personas relacionadas con la iniciativa. Las redes personales de estos tres tipos se resumieron mediante "grafos agrupados"(http://visone.info/wiki/index.php/Personal_networks_%28tutorial%29, los cuales presentan diferentes características para cada tipo, en términos de equilibrio entre lazos fuertes y débiles de apoyo a la iniciativa empresarial. Sostenemos que este nuevo escenario en el que nuevos y viejos actores se esfuerzan por presentarse a sí mismos con las etiquetas disponibles difícilmente puede entenderse sólo en términos de las motivaciones sociales, como sugiere la literatura. Por último, se presenta una conceptualización del campo del "empresariado social" como consecuencia del avance del neoliberalismo y la reducción del gasto público destinado a las clases medias y populares en Europa a partir de la crisis financiera.

  10. Las redes sociales virtuales como espacios de ocio digital

    Directory of Open Access Journals (Sweden)

    Viñals Blanco, Ana

    2013-06-01

    Full Text Available En español: Vivimos en una sociedad digital donde los hábitos y estilos de vida se han visto transformados debido al desarrollo de Internet y las nuevas Tecnologías de la Información y la Comunicación (TIC. El ocio, entendido en este artículo como experiencia de desarrollo humano (Cuenca, 2000 y ámbito vital, tampoco se ha resistido a la influencia de la tecnología y la esfera virtual, dando pié a la generación de nuevos ocios virtuales entre los que destaca el uso de las redes sociales. Son parte de las nuevas prácticas de ocio de los jóvenes españoles y los nuevos formatos de entretenimiento. Fundamentándonos en el modo de entender el ocio del Instituto de Estudios de Ocio de la Universidad de Deusto y en la dicotomía de ocio serio y ocio casual defendida por Stebbins (2008, pretendemos dar respuesta a los siguientes planteamientos: ¿de qué manera ha influido la revolución digital en el ámbito del ocio?, ¿nos encontramos ante nuevos formatos de entretenimiento de carácter consumista o bien ante prácticas de ocio digital que fomentan el desarrollo personal? Esto nos llevará a analizar los usos que los jóvenes pertenecientes a la generación digital hacen de las redes sociales virtuales. In english: We live in a digital society where habits and lifestyles have been transformed by the development of the Internet and New Technologies of Information and Communication (ICT. Leisure, understood in this article as an experience of human development (Cuenca, 2000 and vital area, neither has resisted the influence of technology and the virtual sphere, and that caused the generation of new virtual leisures, among which the most important is the use of social networks. They are part of the new leisure practices of Spanish young people and new entertainment formats. Based on the way of understanding the concept of leisure inherent to Institute of Leisure Studies of the University of Deusto and the dichotomy between of serious

  11. Impacto del ENUM en las redes y los servicios

    Directory of Open Access Journals (Sweden)

    Nelson A. Prieto Rivero2

    2010-09-01

    Full Text Available Normal 0 21 false false false ES-TRAD X-NONE X-NONE MicrosoftInternetExplorer4 st1:*{behavior:url(#ieooui } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} El ENUM o  “Correspondencia de Números Telefónicos” mas conocido por sus siglas en idioma inglés “ENUM” –Telephone Number Mapping- desarrollado por la Internet Engineering Task Force (IETF se le considera el primer servicio de convergencia de las redes telefónicas y de la Internet y se basa en la asociación de números telefónicos con recursos de red o servicios en el sistema de Nombre de Dominio o DNS. El ENUM se enmarca dentro de los esfuerzos de los Organismos Mundiales de Normalización (IETF, UIT, ETSI en la consecución de un identificador personal para las telecomunicaciones. El ENUM es la base de nuevos servicios en los cuales no se tiene experiencia práctica por lo que se ha  considerado acometer un desarrollo que en un principio se desplegará como ENUM de Usuario en la Intranet de ETECSA. El presente trabajo expone un análisis del ENUM, su impacto en las redes y servicios así como una breve descripción de algunos trabajos preliminares que sobre el mismo se vienen realizando en ETECSA

  12. Transmisión de audio usando redes Zigbee

    Directory of Open Access Journals (Sweden)

    David Delgado León

    2011-03-01

    Full Text Available Normal 0 21 false false false MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} Normal 0 21 false false false MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} Zigbee es un protocolo de comunicaciones basado en el estándar para redes inalámbricas IEEE_802.15.4. Concebido para el control y la monitorización de redes de sensores tanto en entornos industriales, médicos, como domóticos, ha existido un creciente interés por evaluarlo en aplicaciones de multimedia. Aun sin garantizar QoS (Quality of service por su limitado ancho de banda existen un conjunto de aplicaciones para vigilancia, grupos de rescate y salvamento, seguridad en entornos domóticos, grupos desplegados en un área limitada con necesidad de comunicación donde un sistema de audio y video en tiempo real de bajo costo basado en tecnología Zigbee es una idea sumamente atractiva.   Se presenta el diseño de un sistema que permita la comunicación de un grupo de usuarios desplegadas en un área limitada. Utiliza Microcontroladores RISC y tecnología Zigbee. Se investiga la factibilidad de usar la tecnología Zigbee para la transmisión de audio, se analizan

  13. REDES SOCIAIS E FORMAÇÃO DE PROFESSORES

    Directory of Open Access Journals (Sweden)

    Gilmara Teixeira Barcelos

    2012-09-01

    Full Text Available Os desafios estabelecidos pelas inovações tecnológicas ao processo educativo são muitos e diversas são as alternativas de práticas pedagógicas que envolvem o uso das mesmas. Nessa perspectiva, esta conferência visa a apresentar uma pesquisa que discute a prática pedagógica alicerçada nas tecnologias digitais (TD como instrumentos mediadores. Considerando que a formação de professores é um processo contínuo, foi elaborada uma proposta de formação, para os egressos da licenciatura em Matemática de um Instituto Federal, no início de sua prática docente . A proposta foi denominada T-PROIM – Tecnologias na Prática docente de pROfessores Iniciantes de Matemática. Uma rede social na Internet (RSI foi implementada por meio da plataforma Elgg para apoiar a referida formação. Essa visou a possibilitar a integração das TD à prática docente e fundamentou-se na teoria sócio-histórica. A pesquisa foi descritiva e explicativa, por meio de um estudo de caso e a abordagem foi, predominantemente, qualitativa. As técnicas de coleta de dados foram questionário, entrevistas, observação e registro dos conteúdos postados na RSI. Para tanto, inicialmente, caracterizam-se redes sociais na internet. A seguir, são apresentados os aspectos metodológicos, as características da formação T-PROIM e a análise macro da experimentação da referida formação. Finalizando, são tecidas algumas considerações sobre a pesquisa. A flexibilidade da formação e da configuração de recursos RSI foi considerada importante para o contexto educacional. Além disso, a análise possibilitou identificar que a confiança no uso pedagógico das TD aumentou e que a formação contribuiu para o desenvolvimento pessoal, social e cognitivo.

  14. Mesmerising mirror neurons.

    Science.gov (United States)

    Heyes, Cecilia

    2010-06-01

    Mirror neurons have been hailed as the key to understanding social cognition. I argue that three currents of thought-relating to evolution, atomism and telepathy-have magnified the perceived importance of mirror neurons. When they are understood to be a product of associative learning, rather than an adaptation for social cognition, mirror neurons are no longer mesmerising, but they continue to raise important questions about both the psychology of science and the neural bases of social cognition. Copyright 2010 Elsevier Inc. All rights reserved.

  15. The mirror neuron system.

    Science.gov (United States)

    Cattaneo, Luigi; Rizzolatti, Giacomo

    2009-05-01

    Mirror neurons are a class of neurons, originally discovered in the premotor cortex of monkeys, that discharge both when individuals perform a given motor act and when they observe others perform that same motor act. Ample evidence demonstrates the existence of a cortical network with the properties of mirror neurons (mirror system) in humans. The human mirror system is involved in understanding others' actions and their intentions behind them, and it underlies mechanisms of observational learning. Herein, we will discuss the clinical implications of the mirror system.

  16. Integralidade e redes de cuidado: uma experiência do PET-Saúde/Rede de Atenção Psicossocial

    Directory of Open Access Journals (Sweden)

    Maria Lenz Cesar Kemper

    2015-12-01

    Full Text Available O presente artigo aborda a formação em saúde a partir da experiência do PET- Saúde/Rede de Atenção Psicossocial: priorizando o enfrentamento do álcool, crack e outras drogas, da Universidade Federal do Rio de Janeiro - UFRJ. Compreendendo o cuidado em saúde mental como uma prática integral que inclui redes variadas e complexas (formal, territorial e familiar, a metodologia deste PET se utiliza da cartografia, convidando o pesquisador a estar no território e no cotidiano do usuário. Assim, aposta-se numa formação ampliada dos alunos de graduação, ao se ofertar um campo de interlocução entre teoria e prática. Alguns casos são apresentados para ilustrar essa experiência, que visa a identificar e intervir na dinâmica das redes de cuidado. A ampliação da compreensão de rede e o mapeamento de territórios afetivos expandem as possibilidades de um cuidado integral, promovendo saúde e qualidade de vida.

  17. Redes Sociais e Juventude Rural: apropriações de propostas de Comunicação para o desenvolvimento em redes globalizadas

    Directory of Open Access Journals (Sweden)

    Nataly de Queiroz Lima

    Full Text Available Este artigo objetiva analisar as apropriações das propostas da Rede de Crianças e Adolescentes Comunicadores de Língua Portuguesa pelos jovens de Nova Olinda, no sertão do Ceará. Especificamente, o que se quer compreender é como os jovens de contexto popular, submetidos à condição contingente de acesso a bens materiais e simbólicos, se apropriam de uma proposta que defende o desenvolvimento local via estratégias de Comunicação acordadas em uma rede social global. A pesquisa combina as teorias dos estudos culturais latino-americanos e dos estudos das redes sociais, via Manuel Castells, Scherer-Warren, Néstor García Canclini, Maria Salett Tauk Santos e Jesus Martin-Barbero. Trata-se de um estudo de caso que utiliza técnicas combinadas de coleta de dados. A pesquisa demonstra que os jovens rurais estão inseridos nas dinâmicas das redes sociais, mas as mediações tecnológicas não são redentoras para a formação de coletivos internacionais.

  18. Application of ANNS in tube CHF prediction: effect on neuron number in hidden layer

    International Nuclear Information System (INIS)

    Han, L.; Shan, J.; Zhang, B.

    2004-01-01

    Prediction of the Critical Heat Flux (CHF) for upward flow of water in uniformly heated vertical round tube is studied with Artificial Neuron Networks (ANNs) method utilizing different neuron number in hidden layers. This study is based on thermal equilibrium conditions. The neuron number in hidden layers is chosen to vary from 5 to 30 with the step of 5. The effect due to the variety of the neuron number in hidden layers is analyzed. The analysis shows that the neuron number in hidden layers should be appropriate, too less will affect the prediction accuracy and too much may result in abnormal parametric trends. It is concluded that the appropriate neuron number in two hidden layers should be [15 15]. (authors)

  19. Label-free visualization of ultrastructural features of artificial synapses via cryo-EM.

    Science.gov (United States)

    Gopalakrishnan, Gopakumar; Yam, Patricia T; Madwar, Carolin; Bostina, Mihnea; Rouiller, Isabelle; Colman, David R; Lennox, R Bruce

    2011-12-21

    The ultrastructural details of presynapses formed between artificial substrates of submicrometer silica beads and hippocampal neurons are visualized via cryo-electron microscopy (cryo-EM). The silica beads are derivatized by poly-d-lysine or lipid bilayers. Molecular features known to exist at presynapses are clearly present at these artificial synapses, as visualized by cryo-EM. Key synaptic features such as the membrane contact area at synaptic junctions, the presynaptic bouton containing presynaptic vesicles, as well as microtubular structures can be identified. This is the first report of the direct, label-free observation of ultrastructural details of artificial synapses.

  20. On the Construction of Artificial Brains

    CERN Document Server

    Ramacher, Ulrich

    2009-01-01

    This book presents a first generation of artificial brains, using vision as sample application. An object recognition system is built, using neurons and synapses as exclusive building elements. The system contains a feature pyramid with 8 orientations and 5 resolution levels for 1000 objects and networks for binding of features into objects. This vision system can recognize objects robustly in the presence of changes in illumination, deformation, distance and pose (as long as object components remain visible). The neuro-synaptic network owes its functional power to the introduction of rapidly modifiable dynamic synapses. These give a network greater pattern recognition capabilities than are achievable with fixed connections. The spatio-temporal correlation structure of patterns is captured by a single synaptic differential equation in a universal way. The correlation can appear as synchronous neural firing, which signals the presence of a feature in a robust way, or binds features into objects. Although in th...

  1. Biomaterials for artificial organs

    CERN Document Server

    Lysaght, Michael J

    2010-01-01

    The worldwide demand for organ transplants far exceeds available donor organs. Consequently some patients die whilst waiting for a transplant. Synthetic alternatives are therefore imperative to improve the quality of, and in some cases, save people's lives. Advances in biomaterials have generated a range of materials and devices for use either outside the body or through implantation to replace or assist functions which may have been lost through disease or injury. Biomaterials for artificial organs reviews the latest developments in biomaterials and investigates how they can be used to improve the quality and efficiency of artificial organs. Part one discusses commodity biomaterials including membranes for oxygenators and plasmafilters, titanium and cobalt chromium alloys for hips and knees, polymeric joint-bearing surfaces for total joint replacements, biomaterials for pacemakers, defibrillators and neurostimulators and mechanical and bioprosthetic heart valves. Part two goes on to investigate advanced and ...

  2. Artificial structures on Mars

    Science.gov (United States)

    Van Flandern, T.

    2002-05-01

    Approximately 70,000 images of the surface of Mars at a resolution of up to 1.4 meters per pixel, taken by the Mars Global Surveyor spacecraft, are now in public archives. Approximately 1% of those images show features that can be broadly described as `special shapes', `tracks, trails, and possible vegetation', `spots, stripes, and tubes', `artistic imagery', and `patterns and symbols'. Rather than optical illusions and tricks of light and shadow, most of these have the character that, if photographed on Earth, no one would doubt that they were the products of large biology and intelligence. In a few cases, relationships, context, and fulfillment of a priori predictions provide objective evidence of artificiality that is exempt from the influence of experimenter biases. Only controlled test results can be trusted because biases are strong and operate both for and against artificiality.

  3. Artificial intelligence in medicine

    OpenAIRE

    Scerri, Mariella; Grech, Victor E.

    2016-01-01

    Various types of artificial intelligence programs are already available as consultants to physicians, and these help in medical diagnostics and treatment. At the time of writing, extant programs constitute “weak” AI—lacking in consciousness and intentionality. With AI currently making rapid progress in all domains, including those of healthcare, physicians face possible competitors—or worse, claims that doctors may become obsolete. We will explore the development of AI and robotics in medicin...

  4. Essentials of artificial intelligence

    CERN Document Server

    Ginsberg, Matt

    1993-01-01

    Since its publication, Essentials of Artificial Intelligence has beenadopted at numerous universities and colleges offering introductory AIcourses at the graduate and undergraduate levels. Based on the author'scourse at Stanford University, the book is an integrated, cohesiveintroduction to the field. The author has a fresh, entertaining writingstyle that combines clear presentations with humor and AI anecdotes. At thesame time, as an active AI researcher, he presents the materialauthoritatively and with insight that reflects a contemporary, first hand

  5. Intelligible Artificial Intelligence

    OpenAIRE

    Weld, Daniel S.; Bansal, Gagan

    2018-01-01

    Since Artificial Intelligence (AI) software uses techniques like deep lookahead search and stochastic optimization of huge neural networks to fit mammoth datasets, it often results in complex behavior that is difficult for people to understand. Yet organizations are deploying AI algorithms in many mission-critical settings. In order to trust their behavior, we must make it intelligible --- either by using inherently interpretable models or by developing methods for explaining otherwise overwh...

  6. Intelligence in Artificial Intelligence

    OpenAIRE

    Datta, Shoumen Palit Austin

    2016-01-01

    The elusive quest for intelligence in artificial intelligence prompts us to consider that instituting human-level intelligence in systems may be (still) in the realm of utopia. In about a quarter century, we have witnessed the winter of AI (1990) being transformed and transported to the zenith of tabloid fodder about AI (2015). The discussion at hand is about the elements that constitute the canonical idea of intelligence. The delivery of intelligence as a pay-per-use-service, popping out of ...

  7. Artificial neural network modelling

    CERN Document Server

    Samarasinghe, Sandhya

    2016-01-01

    This book covers theoretical aspects as well as recent innovative applications of Artificial Neural networks (ANNs) in natural, environmental, biological, social, industrial and automated systems. It presents recent results of ANNs in modelling small, large and complex systems under three categories, namely, 1) Networks, Structure Optimisation, Robustness and Stochasticity 2) Advances in Modelling Biological and Environmental Systems and 3) Advances in Modelling Social and Economic Systems. The book aims at serving undergraduates, postgraduates and researchers in ANN computational modelling. .

  8. Neuromorphic Silicon Neuron Circuits

    Science.gov (United States)

    Indiveri, Giacomo; Linares-Barranco, Bernabé; Hamilton, Tara Julia; van Schaik, André; Etienne-Cummings, Ralph; Delbruck, Tobi; Liu, Shih-Chii; Dudek, Piotr; Häfliger, Philipp; Renaud, Sylvie; Schemmel, Johannes; Cauwenberghs, Gert; Arthur, John; Hynna, Kai; Folowosele, Fopefolu; Saighi, Sylvain; Serrano-Gotarredona, Teresa; Wijekoon, Jayawan; Wang, Yingxue; Boahen, Kwabena

    2011-01-01

    Hardware implementations of spiking neurons can be extremely useful for a large variety of applications, ranging from high-speed modeling of large-scale neural systems to real-time behaving systems, to bidirectional brain–machine interfaces. The specific circuit solutions used to implement silicon neurons depend on the application requirements. In this paper we describe the most common building blocks and techniques used to implement these circuits, and present an overview of a wide range of neuromorphic silicon neurons, which implement different computational models, ranging from biophysically realistic and conductance-based Hodgkin–Huxley models to bi-dimensional generalized adaptive integrate and fire models. We compare the different design methodologies used for each silicon neuron design described, and demonstrate their features with experimental results, measured from a wide range of fabricated VLSI chips. PMID:21747754

  9. Neuromorphic silicon neuron circuits

    Directory of Open Access Journals (Sweden)

    Giacomo eIndiveri

    2011-05-01

    Full Text Available Hardware implementations of spiking neurons can be extremely useful for a large variety of applications, ranging from high-speed modeling of large-scale neural systems to real-time behaving systems, to bidirectional brain-machine interfaces. The specific circuit solutions used to implement silicon neurons depend on the application requirements. In this paper we describe the most common building blocks and techniques used to implement these circuits, and present an overview of a wide range of neuromorphic silicon neurons, which implement different computational models, ranging from biophysically realistic and conductance based Hodgkin-Huxley models to bi-dimensional generalized adaptive Integrate and Fire models. We compare the different design methodologies used for each silicon neuron design described, and demonstrate their features with experimental results, measured from a wide range of fabricated VLSI chips.

  10. Redes sociales, literacidad e identidad (es: el caso de Facebook

    Directory of Open Access Journals (Sweden)

    Alfonso Vargas Franco

    2016-05-01

    Full Text Available En este artículo se presentan los primeros resultados de una investigación sobre las relaciones entre prácticas letradas e identidad en la red social Facebook. En este estudio se analiza el papel que juegan las prácticas letradas en una red social como Facebook y como éstas inciden en la construcción de las identidades individuales y colectivas de los sujetos informantes. En el estudio se argumenta que se están produciendo profundas transformaciones en los modos de leer y escribir como resultado de las tecnologías digitales y las redes sociales, y que a través de los discursos multimodales los sujetos construyen de manera más abierta y dinámica sus identidades individuales y colectivas. El corpus está constituido por las entrevistas en profundidad a dos informantes, grabadas y transcritas siguiendo el modelo de análisis del discurso. El estudio de corte cualitativo-etnográfico arroja como resultados preliminares que los usuarios de la red social Facebook despliegan una intensa actividad letrada con un fuerte componente identitario.

  11. de redes de organizaciones civiles (ONG's en México

    Directory of Open Access Journals (Sweden)

    Giovanna Mazzotti Pabello

    2006-01-01

    Full Text Available Considerando que una de las cuestiones mas importantes que ha tenido lugar en el campo de las organizaciones civiles (ONG’s a nivel mundial es la tendencia creciente a asociarse con otras organizaciones como estrategia para asegurar la perdurabilidad e incrementar el impacto de su trabajo. En este artículo presentamos el modo en que tiene lugar los procesos de asociación y constitución de redes de ONG’s en México y describimos las formas particulares en que, al relacionarse con la población, promueven o no, la existencia de un tipo de capital social que les permita no sólo asegurar su sobrevivencia como organizaciones sino generar las condiciones sociales y políticas para lograr la promoción de un tipo de desarrollo dirigido a la satisfacción de las necesidades objetivas, subjetivas, emocionales y estéticas de la población.

  12. Complexidade e as Redes de Economia Solidária

    Directory of Open Access Journals (Sweden)

    Luís Miguel Luiz dos Santos

    2013-03-01

    Full Text Available O objetivo primordial da elaboração deste ensaio é demonstrar como as redes de economia solidária, que emergem como um contramovimento à hegemonia individualista capitalista, podem se constituir num modelo socioeconômico mais factível e sustentável. Parte-se, através do pensamento complexo de Edgar Morin, do pressuposto que a crise social hoje vivenciada é, sobretudo, uma crise no modo como o conhecimento foi concebido na sociedade moderna. Nesse contexto, argumenta-se que a economia solidária constitui-se numa forma de produção e sociabilidade mais condizente com os desafios do mundo atual, considerando as contradições e desequilíbrios socioambientais crescentes, em que os modelos organizacionais convencionais apoiados no isolamento das partes, na hiperespecialização e na fragmentação e isolamento dos saberes, demonstram-se incapazes de superar as incoerências e ameaças à própria sustentabilidade sistêmica.

  13. Redes económicas y desigualdades sociales

    Directory of Open Access Journals (Sweden)

    MARIANO FERNÁNDEZ ENGUITA

    1993-01-01

    Full Text Available Se propone un marco general para la interpretación de las desigualdades sociales según el cual éstas, o las más relevantes de éstas, se configuran en torno a redes económicas de carácter inclusivo (hogares y estados o voluntario (organizaciones y mercados. Organizaciones y mercados movilizan los medios de producción, la fuerza de trabajo y la ciencia y la técnica, y el control diferencial sobre estos factores toma respectivamente la forma de propiedad, autoridad y cualificación. Hogares y estados son el origen de las diferencias genéricas y generacionales, los primeros, y comunitarias y étnicas, los segundos. En la economía abierta, formada por organizaciones y mercados, la propiedad, la autoridad y la cualificación sirven de base a relaciones de explotación (transferencia de excedente y dividen a la sociedad en clases, mientras que el género, la generación y la etnia sirven de base a relaciones de privilegio (oportunidades desiguales y la dividen en categorías.

  14. PUBLICIDAD INFANTIL EN LAS REDES SOCIALES: TIPOGRAFÍA DIGITAL

    Directory of Open Access Journals (Sweden)

    Jaime Pabón Villamizar

    2014-06-01

    Full Text Available La evolución tecnológica y publicitaria ha producido paralelamente la vinculación infantil en su entorno consumista, debido a que los niños han pasado a ser un target muy apetecido por su vulnerabilidad. Las redes sociales permiten a los medios publicitaros a través de internet humanizar las marcas, creando perfiles en las diversas plataformas de sociabilización digital, ofreciéndole además un valor adicional a los productos, llegando a los niños de forma más directa y personal, con el fin de dejar una “huella mental” para así vincularse de forma estrecha con ellos. Para esto la publicidad crea una nueva estrategia que permite llegar de forma más eficiente a los infantes, perfeccionando la expresión audiovisual y resaltando la tipografía como medio más frecuente en internet y relevante en la compresión del mensaje y así generar publicidades totalmente efectivas creando dependencias de las marcas, no sólo en la actualidad sino a futuro.

  15. Jogos Multiplayer o poder das redes de entretenimento

    Directory of Open Access Journals (Sweden)

    Isa de Jesus Coutinho

    2015-02-01

    Full Text Available Os games em MMO Massive Multiplayer Online, “Multijogadores Massivos Online” surgiram a partir da conectividade com a internet, diferente dos primeiros jogos que eram desenvolvidos apenas para computadores. Este tipo de interação vem adquirindo importante avanço na indústria do entretenimento, bem como motivando estudos em distintas partes do planeta. Diretamente associado a este amplo e instigante tema situa-se a obra espanhola “Jogos Multiplayer; o poder das redes em entretenimento”, recentemente disponibilizada no Brasil, com prólogo de Gonzalo Frasca. Trata-se de um material útil para introdução a respeito do assunto uma vez que os autores constroem sua argumentação a partir de diferentes lugares teóricos propiciando uma leitura didática, abrangente, e crítica.  Multiplayer online games the power of networks Keywords: Multiplayer online games, connectivity, Multiplayer, Games Online

  16. Leaky Integrate-and-Fire Neuron Circuit Based on Floating-Gate Integrator

    Science.gov (United States)

    Kornijcuk, Vladimir; Lim, Hyungkwang; Seok, Jun Yeong; Kim, Guhyun; Kim, Seong Keun; Kim, Inho; Choi, Byung Joon; Jeong, Doo Seok

    2016-01-01

    The artificial spiking neural network (SNN) is promising and has been brought to the notice of the theoretical neuroscience and neuromorphic engineering research communities. In this light, we propose a new type of artificial spiking neuron based on leaky integrate-and-fire (LIF) behavior. A distinctive feature of the proposed FG-LIF neuron is the use of a floating-gate (FG) integrator rather than a capacitor-based one. The relaxation time of the charge on the FG relies mainly on the tunnel barrier profile, e.g., barrier height and thickness (rather than the area). This opens up the possibility of large-scale integration of neurons. The circuit simulation results offered biologically plausible spiking activity (circuit was subject to possible types of noise, e.g., thermal noise and burst noise. The simulation results indicated remarkable distributional features of interspike intervals that are fitted to Gamma distribution functions, similar to biological neurons in the neocortex. PMID:27242416

  17. Artificial sweetener; Jinko kanmiryo

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-08-01

    The patents related to the artificial sweetener that it is introduced to the public in 3 years from 1996 until 1998 are 115 cases. The sugar quality which makes an oligosaccharide and sugar alcohol the subject is greatly over 28 cases of the non-sugar quality in the one by the kind as a general tendency of these patents at 73 cases in such cases as the Aspartame. The method of manufacture patent, which included new material around other peptides, the oligosaccharide and sugar alcohol isn`t inferior to 56 cases of the formation thing patent at 43 cases, and pays attention to the thing, which is many by the method of manufacture, formation. There is most improvement of the quality of sweetness with 31 cases in badness of the aftertaste which is characteristic of the artificial sweetener and so on, and much stability including the improvement in the flavor of food by the artificial sweetener, a long time and dissolution, fluid nature and productivity and improvement of the economy such as a cost are seen with effect on a purpose. (NEDO)

  18. Antithrombotic artificial organs

    Energy Technology Data Exchange (ETDEWEB)

    Takamatsu, T; Fukada, E; Saegusa, M; Hasegawa, T

    1971-07-12

    A new antithrombotic material useful for making artificial organs (artificial blood vessel, artificial heart, etc.) can be prepared by graft-polymerizing an acrylic ester (methyl methacrylate, methyl acrylate, ethyl acrylate, etc.) with a synthetic fiber (teflon, etc.). The graft-polymerization can be carried out by means of gamma radiation with cobalt 60 (dose rate 2.6x10/sup 3/ r/min., total dose 8x10/sup 4/ to 3.5x10/sup 5/ r). A graft ratio of 5 to 80% is attainable. In one example, a tubular sample made of teflon fiber having an inner diameter of 5 to 10 mm was immersed into methyl methacrylate in an ampoule in the absence of air and exposed to cobalt 60 gamma ray at the dose rate of 3.18x10/sup 3/ rad/min. After extraction with acetone, the sample was dried. The total dose was 3.5x10/sup 5/ rad and the graft ratio was ca. 25%. The sample was transplanted to vena cava of dog. No formation of thrombus was observed by autopsy (4 months after the transplantation). In control (teflon tube not graft-polymerized) thrombus was observed by autopsy 7 days after the transplantation.

  19. On the number of preganglionic neurones driving human postganglionic sympathetic neurones: a comparison of modelling and empirical data

    Directory of Open Access Journals (Sweden)

    Vaughan G Macefield

    2011-12-01

    Full Text Available Postganglionic sympathetic axons in awake healthy human subjects, regardless of their identity as muscle vasoconstrictor, cutaneous vasoconstrictor or sudomotor neurones, discharge with a low firing probability (~30%, generate low firing rates (~0.5 Hz and typically fire only once per cardiac interval. The purpose of the present study was to use modelling of spike trains in an attempt to define the number of preganglionic neurones that drive an individual postganglionic neurone. Artificial spike trains were generated in 1-3 preganglionic neurones converging onto a single postganglionic neurone. Each preganglionic input fired with a mean interval distribution of either 1000, 1500, 2000, 2500 or 3000 ms and the standard deviation varied between 0.5, 1.0 and 2.0 x the mean interval; the discharge frequency of each preganglionic neurone exhibited positive skewness and kurtosis. Of the 45 patterns examined, the mean discharge properties of the postganglionic neurone could only be explained by it being driven by, on average, two preganglionic neurones firing with a mean interspike interval of 2500 ms and SD of 5000 ms. The mean firing rate resulting from this pattern was 0.22 Hz, comparable to that of spontaneously active muscle vasoconstrictor neurones in healthy subjects (0.40 Hz. Likewise, the distribution of the number of spikes per cardiac interval was similar between the modelled and actual data: 0 spikes (69.5 vs 66.6 %, 1 spike (25.6 vs 21.2 %, 2 spikes (4.3 vs 6.4 %, 3 spikes (0.5 vs 1.7 % and 4 spikes (0.1 vs 0.7 %. Although some features of the firing patterns could be explained by the postganglionic neurone being driven by a single preganglionic neurone, none of the emulated firing patterns generated by the firing of three preganglionic neurones matched the discharge of the real neurones. These modelling data indicate that, on average, human postganglionic sympathetic neurones are driven by two preganglionic inputs.

  20. Estimativa de imagens solares soho através de redes neurais artificiais

    Science.gov (United States)

    Andrade, M. C.; Fernandes, F. C. R.; Cecatto, J. R.; Rios Neto, A.; Rosa, R. R.; Sawant, H. S.

    2003-08-01

    A Rede Neural Artificial (RNA), no âmbito da teoria computacional, constitui uma teoria emergente que, por possuir habilidade em aprender a partir de dados de entrada, encontra diferentes aplicações em diferentes áreas. Um exemplo é a utilização de RNA na caracterização de padrões associados à dinâmica de processos espaço-temporais relacionados a fenômenos físicos não-lineares. Para obter informações sobre o comportamento destes fenômenos físicos utiliza-se, em diversos casos, seqüências de imagens digitalizadas, onde a caracterização de alguns fenômenos espaço-temporais é o procedimento mais viável para descrever a dinâmica das regiões ativas do Sol. Com base em imagens observadas por telescópios a bordo de satélites, estudos de previsão de eventos solares podem ser programados, permitindo prever possíveis efeitos posteriores nas regiões mais próximas da Terra (tempestades geomagnéticas e irregularidades ionosféricas). Neste trabalho avaliamos o desempenho da RNA para estimar padrões espaço-temporais, ou seja, imagens solares em ultravioleta, obtidas através do telescópio a bordo do satélite SOHO. Os resultados mostraram que as RNA conseguem generalizar os padrões de maneira satisfatória sem perder de forma significativa os principais aspectos da configuração global da atmosfera solar, comprovando a eficácia da RNA como ferramenta para esse tipo de aplicação. Portanto, este trabalho comprova a viabilidade de uso desta ferramenta em projetos voltados ao estudo do comportamento solar, em trabalhos do grupo de Física do Meio Interplanetário (FMI) na DAS e em programas desenvolvidos pelo Núcleo de Simulação e Análise de Sistemas Complexos (NUSASC) do Laboratório Associado de Computação e Matemática Aplicada (LAC) do INPE.

  1. OS BENEFÍCIOS PERCEBIDOS PELOS PRINCIPAIS STAKEHOLDERS DE UMA REDE DE EMPRESAS

    Directory of Open Access Journals (Sweden)

    Caroline Metzger

    2008-01-01

    Full Text Available O presente artigo retrata um estudo relacionado aos benefícios percebidos pelos principais stakeholders de uma rede de empresas. Para tanto, desenvolveu-se uma pesquisa bibliográfica sobre a pequena empresa, os antecedentes históricos das redes de empresas, os conceitos relacionados, as tipologias e características estruturais, os benefícios proporcionados pelas redes e apresentou-se o Programa Redes de Cooperação no Estado do Rio Grande do Sul. Descreveram-se também os conceitos de stakeholders, as suas classificações e os benefícios do relacionamento destes grupos. Considerando este contexto, o objetivo deste artigo foi identificar e analisar os benefícios percebidos pelos principais stakeholders envolvidos com a rede de cooperação Hipereletro. A metodologia utilizada foi o estudo de caso a partir dos dados coletados através da pesquisa de campo, por meio de um questionário aplicado a quatro grupos envolvidos com a Hipereletro. Após a análise dos dados, identificaram-se os benefícios percebidos por cada stakeholder. Os associados perceberam benefícios nas ações de marketing, nas negociações em conjunto e no relacionamento entre as empresas, destacam-se as promoções realizadas pelo grupo, obtenção de melhores preços nas compras e troca de informações, conhecimentos e experiências. Já os funcionários apontaram a melhora na apresentação da empresa, realização de eventos e a troca de informações entre as lojas. Para os fornecedores, os primeiros reflexos da parceria com a rede foram o aumento das vendas, a garantia de pagamento e a fidelidade das empresas. E, quanto aos clientes, destacaram-se a percepção em relação à mudança da fachada da loja, as promoções e a diferença nos preços dos produtos. Pela pesquisa, concluiu-se que todos percebem benefícios ao se relacionarem com a rede, alguns mais, outros menos. Porém, devido ao pouco tempo de existência da Hipereletro, todos acreditam no

  2. NeuronBank: a tool for cataloging neuronal circuitry

    Directory of Open Access Journals (Sweden)

    Paul S Katz

    2010-04-01

    Full Text Available The basic unit of any nervous system is the neuron. Therefore, understanding the operation of nervous systems ultimately requires an inventory of their constituent neurons and synaptic connectivity, which form neural circuits. The presence of uniquely identifiable neurons or classes of neurons in many invertebrates has facilitated the construction of cellular-level connectivity diagrams that can be generalized across individuals within a species. Homologous neurons can also be recognized across species. Here we describe NeuronBank.org, a web-based tool that we are developing for cataloging, searching, and analyzing neuronal circuitry within and across species. Information from a single species is represented in an individual branch of NeuronBank. Users can search within a branch or perform queries across branches to look for similarities in neuronal circuits across species. The branches allow for an extensible ontology so that additional characteristics can be added as knowledge grows. Each entry in NeuronBank generates a unique accession ID, allowing it to be easily cited. There is also an automatic link to a Wiki page allowing an encyclopedic explanation of the entry. All of the 44 previously published neurons plus one previously unpublished neuron from the mollusc, Tritonia diomedea, have been entered into a branch of NeuronBank as have 4 previously published neurons from the mollusc, Melibe leonina. The ability to organize information about neuronal circuits will make this information more accessible, ultimately aiding research on these important models.

  3. O uso das redes sociais por jornalistas em Portugal

    Directory of Open Access Journals (Sweden)

    Ana Sofia Veloso

    2015-03-01

    Full Text Available Este artigo pretende mostrar como as redes sociais são utilizadas pelosjornalistas, nomeadamente os que trabalham em Portugal. É ainda intuito deste trabalho perceber se o uso destas ferramentas por estes profissionais pode constituir uma nova prática rotineira.Para o efeito, levou-se a cabo um estudo de carácter exploratório baseado nos resultados de um inquérito por questionário – realizado de raiz – dirigido à classe jornalística em Portugal. O artigo divide-se em quatro partes. Tendo em conta que, em pouco mais de uma década, as redes sociais se tornaram a atividade online mais popular a nível global, começa-se por realizar um enquadramento de apoio ao surgimento destas ferramentas na sociedade atual, dando conta de algumas estatísticas de uso e de novos processos de socialização subsequentes. Num segundo momento, é feito refereência à relação do jornalismo com as redes sociais e algumas novas práticas jornalísticas neste âmbito, apresentando conclusões de estudos internacionais sobre a utilização que jornalistas de diversos países fazem das redes sociais. Aborda-se ainda as orientações existentes sobre o uso ético que os jornalistas devem dar a estas ferramentas segundo várias entidades ligadas ao universo do jornalismo. A terceira parte foca-se no inquérito, designadamente a metodologia usada e a estrutura do mesmo; realiza-se um breve retrato sociográfico da classe jornalística em Portugal e faz-se uma caracterização socioprofissional da amostra obtida através do inquérito; apresentam-se os resultados conseguidos e analisam-se e discutem-se os mesmos, nomeadamente através de comparações com as estatísticas e as conclusões dos estudos nacionais e internacionais já mencionadas. Na quarta secção, tendo por base a discussão realizada e o balanço do tratamento do inquérito, menciona-se alguns desafios que se colocam aos jornalistas na era da Web 2.0. E conclui-se com a confirmação de que a

  4. Mashup de calendarios y localización geográfica de redes sociales

    Directory of Open Access Journals (Sweden)

    Jorge Hernández Mercado

    2010-01-01

    Full Text Available Las redes sociales son unos pilares de la web 2.0, que avanzan a pasos agigantados. Aunque estas redes generalmente interactúan virtualmente, eventualmente se reúnen en un lugar geográfico para llevar a cabo alguna actividad de importancia presencial. Estas actividades son programadas en un calendario donde se asignan fechas y direcciones físicas. Este artículo presenta el desarrollo de GCel, una aplicación web híbrida (Mashup creada para la generación automática de calendarios y localizaciones geográficas de redes sociales usando Google Calendar y Google Map respectivamente. La arquitectura utilizada por GCel es una combinación de aplicaciones jMaki y Jersey. La aplicación Jersey usa servicios web RESTful para acceder a la base de datos de las redes sociales, creada en MySQL. La aplicación jMaki utiliza los widgets: Google Maps, Dojo Table y Yahoo Button. Este último widget toma la información dada por el servicio web RESTful y gracias al mecanismo publish/suscribe de jMaki lo publica a los dos widgets suscritos. Se muestra el uso de GCel para la creación de calendarios y localización geográfica de cada una de las redes sociales de la Fundación Consentir.

  5. Rede social de adolescentes em liberdade assistida na perspectiva da saúde pública

    Directory of Open Access Journals (Sweden)

    Marilene Rivany Nunes

    2016-04-01

    Full Text Available RESUMO Objetivo: analisar o sentido da rede social de adolescentes que cumprem Liberdade Assistida e identificar os componentes essenciais dessa rede. Método: estudo exploratório, de abordagem qualitativa. Participaram do estudo 26 adolescentes com idade de 13 a 18 anos. Para a coleta dos dados, optou-se por entrevista semiestruturada e construção de mapas de rede. Resultados: evidenciou-se a essencialidade da rede social para os adolescentes, destacando-se a importância da família - especialmente a mãe -, e do Centro de Referência Especializado de Assistência Social, para promoção social e construção de um novo projeto de vida, sem envolvimento com atos infracionais. Todavia, os adolescentes não revelaram vínculos com profissionais de saúde. Conclusão: observou-se a necessidade do enfermeiro, enquanto profissional da atenção primária à saúde, atuar de forma intersetorial e interdisciplinar, no sentido de fortalecer a rede social de adolescentes em conflito com a lei.

  6. Redes En Acción. Increasing Hispanic participation in cancer research, training, and awareness.

    Science.gov (United States)

    Ramirez, Amelie G; Talavera, Gregory A; Marti, Jose; Penedo, Frank J; Medrano, Martha A; Giachello, Aida L; Pérez-Stable, Eliseo J

    2006-10-15

    Hispanics are affected by many health care disparities. The National Cancer Institute (NCI), through its Special Populations Branch, is supporting networking and capacity-building activities designed to increase Hispanic participation and leadership in cancer research. Redes En Acción established a national network of cancer research centers, community-based organizations, and federal partners to facilitate opportunities for junior Hispanic scientists to participate in training and research projects on cancer control. Since 2000, Redes En Acción has established a network of more than 1800 Hispanic leaders involved in cancer research and education. The project has sustained 131 training positions and submitted 29 pilot projects to NCI for review, with 16 awards for a total of $800,000, plus an additional $8.8 million in competing grant funding based on pilot study results to date. Independent research has leveraged an additional $32 million in non-Redes funding, and together the national and regional network sites have participated in more than 1400 community and professional awareness events. In addition, the program conducted extensive national survey research that provided the basis for the Redes En Acción Latino Cancer Report, a national agenda on Hispanic cancer issues. Redes En Acción has increased participation in cancer control research, training, and awareness among Hispanic scientists and within Hispanic communities. Cancer 2006. (c) 2006 American Cancer Society.

  7. VULNERABILIDAD DE REDES COMPLEJAS Y APLICACIONES AL TRANSPORTE URBANO: UNA REVISIÓN DE LA LITERATURA

    Directory of Open Access Journals (Sweden)

    Laura Lotero Vélez

    Full Text Available El interés de investigadores y profesionales de diversas disciplinas en el análisis de sistemas sociales, biológicos y artificiales desde la perspectiva de las redes complejas ha crecido notablemente en los últimos años. Algunas de estas redes son la base de muchas de las actividades del ser humano, como es el caso de las redes de transporte urbano que hacen parte de la infraestructura crítica. Una de las propiedades de mayor relevancia práctica de las redes complejas es su capacidad para mantener algunas funciones cuando ocurren fallas, errores o ataques a sus nodos o vínculos, la cual ha sido denominada robustez, resiliencia o vulnerabilidad por distintos autores. En este artículo se presenta una revisión de la literatura sobre el concepto de vulnerabilidad en el formalismo de las redes complejas y algunas aplicaciones al transporte urbano. El propósito de este artículo de revisión es el de dar a conocer a académicos y tomadores de decisión nuevos enfoques para el análisis del sistema de movilidad.

  8. Ambientes Colaborativos Virtuais: potencial das redes sociais. O caso das empresas do Algarve

    Directory of Open Access Journals (Sweden)

    Ana Belo

    2013-12-01

    Full Text Available O objetivo do presente artigo é analisar o potencial das redes sociais no desempenho das pequenas e médias empresas da região do Algarve, tendo sido efectuado um questionário para o efeito. O estudo empírico realizado revela que os dados recolhidos (de 70 empresas possuem boas qualidades psico-métricas. Procedeu-se a uma análise categórica de componentes principais, a qual identificou duas principais tipologias de objectivos nas redes sociais: redes sociais para interacção produto-cliente e pesquisa ou conhecimento; e redes sociais com potencial para o marketing. Uma análise suplementar - análise hierárquica de clusters (com recurso ao método de agrupamento de Ward - identificou três padrões de empresas consoante o seu grau de envolvimento em redes sociais: cluster Social Tec Grau 1; cluster Social Tec Grau 2 e cluster Social Tec Grau 3. Estas análises permitem validar uma metodologia sustentável para este tipo de avaliação.

  9. Red neuronal artificial en respuesta a predicciones de parámetros de transferencia de masa (pérdida de humedad y ganancia de sólidos durante la deshidratación osmótica de frutas

    Directory of Open Access Journals (Sweden)

    Claudia Isabel Ochoa Martínez

    2016-10-01

    Full Text Available Los modelos para predecir las cinéticas de pérdida de agua (ML y ganancia de sólidos (SG empleando redes neuronales artificiales (ANN han demostrado tener mejor comportamiento que los demás modelos desarrollados debido a que correlacionan empíricamente gran cantidad de las variables con ML y SG. La principal ventaja de estos modelos es que son predictivos en vez de correlativos, además pueden implementarse fácilmente en una hoja de datos, y son muy útiles y prácticos para el diseño y control del proceso. El objetivo de este trabajo es emplear un modelo desarrollado con ANN para predecir resultados en procesos de deshidratación osmótica. Se hicieron predicciones de comportamiento con diferentes condiciones de proceso y se validaron con resultados experimentales presentados en la literatura. Se obtuvieron buenas predicciones de ML (MRE 19% y un comportamiento variable para SG (MRE 62%.

  10. Spider Silk as Guiding Biomaterial for Human Model Neurons

    Directory of Open Access Journals (Sweden)

    Frank Roloff

    2014-01-01

    Full Text Available Over the last years, a number of therapeutic strategies have emerged to promote axonal regeneration. An attractive strategy is the implantation of biodegradable and nonimmunogenic artificial scaffolds into injured peripheral nerves. In previous studies, transplantation of decellularized veins filled with spider silk for bridging critical size nerve defects resulted in axonal regeneration and remyelination by invading endogenous Schwann cells. Detailed interaction of elongating neurons and the spider silk as guidance material is unknown. To visualize direct cellular interactions between spider silk and neurons in vitro, we developed an in vitro crossed silk fiber array. Here, we describe in detail for the first time that human (NT2 model neurons attach to silk scaffolds. Extending neurites can bridge gaps between single silk fibers and elongate afterwards on the neighboring fiber. Culturing human neurons on the silk arrays led to an increasing migration and adhesion of neuronal cell bodies to the spider silk fibers. Within three to four weeks, clustered somata and extending neurites formed ganglion-like cell structures. Microscopic imaging of human neurons on the crossed fiber arrays in vitro will allow for a more efficient development of methods to maximize cell adhesion and neurite growth on spider silk prior to transplantation studies.

  11. El uso de las redes sociales como herramienta de marketing por parte de las universidades españolas

    OpenAIRE

    Rodríguez Gascón, Alicia

    2017-01-01

    Analizar el uso de las redes sociales como herramienta de marketing por parte de las Universidades Españolas -Identificar que Universidades españolas utilizan las redes sociales como herramienta de comunicación y cómo lo hacen Facultad de Ciencias de la Empresa Universidad Politécnica de Cartagena

  12. Sweet taste and nutrient value subdivide rewarding dopaminergic neurons in Drosophila.

    Science.gov (United States)

    Huetteroth, Wolf; Perisse, Emmanuel; Lin, Suewei; Klappenbach, Martín; Burke, Christopher; Waddell, Scott

    2015-03-16

    Dopaminergic neurons provide reward learning signals in mammals and insects [1-4]. Recent work in Drosophila has demonstrated that water-reinforcing dopaminergic neurons are different to those for nutritious sugars [5]. Here, we tested whether the sweet taste and nutrient properties of sugar reinforcement further subdivide the fly reward system. We found that dopaminergic neurons expressing the OAMB octopamine receptor [6] specifically convey the short-term reinforcing effects of sweet taste [4]. These dopaminergic neurons project to the β'2 and γ4 regions of the mushroom body lobes. In contrast, nutrient-dependent long-term memory requires different dopaminergic neurons that project to the γ5b regions, and it can be artificially reinforced by those projecting to the β lobe and adjacent α1 region. Surprisingly, whereas artificial implantation and expression of short-term memory occur in satiated flies, formation and expression of artificial long-term memory require flies to be hungry. These studies suggest that short-term and long-term sugar memories have different physiological constraints. They also demonstrate further functional heterogeneity within the rewarding dopaminergic neuron population. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  13. Neuronal avalanches and learning

    Energy Technology Data Exchange (ETDEWEB)

    Arcangelis, Lucilla de, E-mail: dearcangelis@na.infn.it [Department of Information Engineering and CNISM, Second University of Naples, 81031 Aversa (Italy)

    2011-05-01

    Networks of living neurons represent one of the most fascinating systems of biology. If the physical and chemical mechanisms at the basis of the functioning of a single neuron are quite well understood, the collective behaviour of a system of many neurons is an extremely intriguing subject. Crucial ingredient of this complex behaviour is the plasticity property of the network, namely the capacity to adapt and evolve depending on the level of activity. This plastic ability is believed, nowadays, to be at the basis of learning and memory in real brains. Spontaneous neuronal activity has recently shown features in common to other complex systems. Experimental data have, in fact, shown that electrical information propagates in a cortex slice via an avalanche mode. These avalanches are characterized by a power law distribution for the size and duration, features found in other problems in the context of the physics of complex systems and successful models have been developed to describe their behaviour. In this contribution we discuss a statistical mechanical model for the complex activity in a neuronal network. The model implements the main physiological properties of living neurons and is able to reproduce recent experimental results. Then, we discuss the learning abilities of this neuronal network. Learning occurs via plastic adaptation of synaptic strengths by a non-uniform negative feedback mechanism. The system is able to learn all the tested rules, in particular the exclusive OR (XOR) and a random rule with three inputs. The learning dynamics exhibits universal features as function of the strength of plastic adaptation. Any rule could be learned provided that the plastic adaptation is sufficiently slow.

  14. Neuronal avalanches and learning

    International Nuclear Information System (INIS)

    Arcangelis, Lucilla de

    2011-01-01

    Networks of living neurons represent one of the most fascinating systems of biology. If the physical and chemical mechanisms at the basis of the functioning of a single neuron are quite well understood, the collective behaviour of a system of many neurons is an extremely intriguing subject. Crucial ingredient of this complex behaviour is the plasticity property of the network, namely the capacity to adapt and evolve depending on the level of activity. This plastic ability is believed, nowadays, to be at the basis of learning and memory in real brains. Spontaneous neuronal activity has recently shown features in common to other complex systems. Experimental data have, in fact, shown that electrical information propagates in a cortex slice via an avalanche mode. These avalanches are characterized by a power law distribution for the size and duration, features found in other problems in the context of the physics of complex systems and successful models have been developed to describe their behaviour. In this contribution we discuss a statistical mechanical model for the complex activity in a neuronal network. The model implements the main physiological properties of living neurons and is able to reproduce recent experimental results. Then, we discuss the learning abilities of this neuronal network. Learning occurs via plastic adaptation of synaptic strengths by a non-uniform negative feedback mechanism. The system is able to learn all the tested rules, in particular the exclusive OR (XOR) and a random rule with three inputs. The learning dynamics exhibits universal features as function of the strength of plastic adaptation. Any rule could be learned provided that the plastic adaptation is sufficiently slow.

  15. Inteligência Artificial e Medicina

    Directory of Open Access Journals (Sweden)

    Luiz Carlos Lobo

    Full Text Available RESUMO Ao mesmo tempo em que se discutem problemas na relação médico-paciente e a deficiência do exame clínico na atenção médica, que torna o diagnóstico clínico mais dependente de exames complementares, enfatiza-se cada vez mais a importância do computador em medicina e na saúde pública. Isto se dá seja pela adoção de sistemas de apoio à decisão clínica, seja pelo uso integrado de novas tecnologias, incluindo as tecnologias vestíveis/corporais (wearable devices, seja pelo armazenamento de grandes volumes de dados de saúde de pacientes e da população. A capacidade de armazenamento e processamento de dados aumentou exponencialmente ao longo dos recentes anos, criando o conceito de big data. A Inteligência Artificial processa esses dados por meio de algoritmos, que tendem a se aperfeiçoar pelo seu próprio funcionamento (self learning e a propor hipóteses diagnósticas cada vez mais precisas. Sistemas computadorizados de apoio à decisão clínica, processando dados de pacientes, têm indicado diagnósticos com elevado nível de acurácia. O supercomputador da IBM, denominado Watson, armazenou um volume extraordinário de informações em saúde, criando redes neurais de processamento de dados em vários campos, como a oncologia e a genética. Watson assimilou dezenas de livros-textos em medicina, toda a informação do PubMed e Medline, e milhares de prontuários de pacientes do Sloan Kettering Memorial Cancer Hospital. Sua rede de oncologia é hoje consultada por especialistas de um grande número de hospitais em todo o mundo. O supercomputador inglês Deep Mind, da Google, registrou informações de 1,6 milhão de pacientes atendidos no National Health Service (NHS, permitindo desenvolver novos sistemas de apoio à decisão clínica, analisando dados desses pacientes, permitindo gerar alertas sobre a sua evolução, evitando medicações contraindicadas ou conflitantes e informando tempestivamente os profissionais de

  16. Deep Learning with Dynamic Spiking Neurons and Fixed Feedback Weights.

    Science.gov (United States)

    Samadi, Arash; Lillicrap, Timothy P; Tweed, Douglas B

    2017-03-01

    Recent work in computer science has shown the power of deep learning driven by the backpropagation algorithm in networks of artificial neurons. But real neurons in the brain are different from most of these artificial ones in at least three crucial ways: they emit spikes rather than graded outputs, their inputs and outputs are related dynamically rather than by piecewise-smooth functions, and they have no known way to coordinate arrays of synapses in separate forward and feedback pathways so that they change simultaneously and identically, as they do in backpropagation. Given these differences, it is unlikely that current deep learning algorithms can operate in the brain, but we that show these problems can be solved by two simple devices: learning rules can approximate dynamic input-output relations with piecewise-smooth functions, and a variation on the feedback alignment algorithm can train deep networks without having to coordinate forward and feedback synapses. Our results also show that deep spiking networks learn much better if each neuron computes an intracellular teaching signal that reflects that cell's nonlinearity. With this mechanism, networks of spiking neurons show useful learning in synapses at least nine layers upstream from the output cells and perform well compared to other spiking networks in the literature on the MNIST digit recognition task.

  17. Un nuevo enfoque para la resolución de problemas: redes neuronales

    Directory of Open Access Journals (Sweden)

    Jonatán Gómez Perdomo

    2015-05-01

    Full Text Available RESUMEN El siguiente artículo  expone los lineamientos generales de un nuevo enfoque para la resolución de problemas mediante computador. Inspiradas en las redes neuronales biológicas, las redes neuronales artifíciales han  mostrado mayor efectividad para resolver problemas que los enfoques tradicionales no han  solucionado o lo han hecho de manera parcial. En la actualidad este enfoque ha ganado un gran auge, lo cual ha generado en el país grupos de investigación que están trabajando sobre sí mismo. Como parte de su trabajo  en el grupo de la Universidad Nacional, los autores desarrollan una herramienta para el diseño, entrenamiento y simulación de redes neuronales artificiales. Las características generales de esta herramienta  se exponen al final.

  18. Identificação dos fatores determinantes do desempenho das empresas inseridas em redes horizontais

    Directory of Open Access Journals (Sweden)

    Breno Augusto Diniz Pereira

    2006-07-01

    Full Text Available Este trabalho objetiva determinar o impacto do ingresso na rede para as organizações inseridas nesse formato organizacional. O estudo foi realizado por meio de levantamento (survey desenvolvido junto a 135 empresas, sendo os dados analisados de forma predominantemente quantitativa. Os resultados demonstram que a variável “satisfação” está diretamente relacionada a variáveis que garantam o desenvolvimento da rede em um ambiente seguro, sem grandes modificações, assim possibilitando o alcance dos objetivos individuais. Dessa forma, identifica-se que as redes são instituições formadas para atingir determinados objetivos organizacionais, reduzindo as incertezas ambientais, mas não reduzindo o desejo de os agentes agirem isoladamente.

  19. Las redes personales de apoyo en la viudedad en España

    Directory of Open Access Journals (Sweden)

    Luis Ayuso

    2012-01-01

    Full Text Available La viudedad supone un impacto emocional, económico y relacional. Este trabajo analiza las transformaciones que experimentan las redes personales de apoyo de las personas viudas. En su análisis se han realizado diferentes modelos de regresión de Poisson, en los que se examinan los efectos de variables personales, contextuales y actitudinales sobre las redes de apoyo. Los datos proceden del Social Relations and Social Support (International Social Survey Program 2001. Las conclusiones muestran el menor número de apoyos con los que cuentan las personas viudas en relación con las emparejadas, aunque son diferentes por sexo. La mayor pérdida de apoyos se produce en la red familiar secundaria. La movilidad geográfi ca aumenta la red familiar pero disminuye la de amigos. Las actitudes familiaristas y la menor confi anza social contribuyen al mantenimiento de estas redes personales.

  20. Uso de las redes sociales en el sur de Europa. Género y adolescencia

    OpenAIRE

    Málaga Pescador, José Luis

    2017-01-01

    Investigamos en esta tesis el uso de las redes sociales virtuales entre los adolescentes (de 12 a 18 años) de tres países del sur de Europa: España, Italia y Portugal. En concreto se van a estudiar el nivel de penetración de estas redes, su utilización concreta, las pautas de acceso a internet y el uso del teléfono móvil, sus hábitos como clientes o consumidores y el papel de las redes en las actividades de socialización. La información proviene de una encuesta que se aplicó a una muestra de ...

  1. Redes sociales en Educación y propuestas metodológicas para su estudio

    Directory of Open Access Journals (Sweden)

    María Del Socorro Pérez Alcalá

    2015-01-01

    Full Text Available El presente trabajo ofrece un análisis para conceptualizar las redes sociales y las comunidades educativas, plantear su importancia y presentar algunas estrategias me-todológicas para su estudio en dicho ámbito, con énfasis en la interacción y la comu-nicación. En la actualidad, las redes sociales crecen de manera acelerada en diversos contextos, entre ellos, el educativo. Las instituciones educativas se han interesado por incorporar las redes sociales como apoyo a los procesos formativos de estudiantes y profesores. Las acciones hasta el momento no han sido generalizadas, por lo que surge la inquietud de realizar investigaciones que den cuenta de las fortalezas y las debilidades sobre la pertinencia y efectos de su uso con tales fines.

  2. Adultos idosos e redes sociais: que motivação? Que aprendizagem?

    OpenAIRE

    Patrício, Maria Raquel; Osório, António

    2013-01-01

    As redes sociais já não são novidade para a maioria das pessoas. Crianças, jovens, adultos e idosos aderem, cada vez mais, a esta forma de comunicação, interação, publicação e partilha online. As redes sociais implementaram-se de tal forma na sociedade que uma grande parte da população adulta idosa, mesmo não tendo um perfil nestas redes, tem conhecimento da sua existência e manifesta curiosidade em aprender a usá-las. Neste sentido, formulamos as seguintes questões: qual a motivação dos adul...

  3. Application of artificial intelligence to electrofacies identification: neural networks versus discriminant analysis; Aplicacao de inteligencia artificial na identificacao de eletrofacies redes neuroniais versus analise discriminante

    Energy Technology Data Exchange (ETDEWEB)

    Silva Rodrigues, F da [PETROBRAS, Rio de Janeiro, RJ (Brazil); Queiroz Neto, I.A. de [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

    1992-07-01

    Electro-facies are identified by neural network trained with well log and core data. Differences between neural network and expert system are discussed. According the author, the combination of neural network computing and traditional computing methods, like discriminant analysis, can help in the solution of many problems in electro-facies identification. 5 figs., 1 tab., 11 refs.

  4. Redes de seguridad para cierre vertical de fachadas

    Directory of Open Access Journals (Sweden)

    Riquelme, P.

    2014-03-01

    Full Text Available Among other methods, vertical safety nets on the façades of buildings during the construction stage are used in Spain as an alternative to other safety systems in order to avoid falls to a different level. There are two kinds of such nets: floor-to-ceiling nets - that secure the entire void between successive floors in structure construction stage-, and small nets what secure windows and other minor voids in later stages. Their design and requirements are not defined at present, but the AEN/CTN81/SC2/GT7 Spanish Working Group is drafting a specific regulation named Pr UNE 81651. Some members of the Civil Engineering Department of the University of Alicante, having experience in other systems of protection, have developed several finite-elements numerical models to measure and analyse mechanical variables related to a possible fall of a person over this kind of net, characterised by a kinetic energy lower than for other types. In this paper the obtained results are shown, for both large and little nets, analysing the anchorages gap, void openings at perimeter, maximum net deflection and net disposal (square/diamond repercussion, as well as its consequences on the victim’s safety (impact factor.Entre otros medios de protección colectiva, en los últimos años se vienen utilizando en España redes verticales de cierre de fachadas, a paño completo entre forjados en fase de estructura, y también para huecos menores como ventanas o puertas, en fases posteriores. Este tipo de protección no cuenta hasta el momento con ningún tipo de regulación oficial, si bien en el grupo de trabajo AEN/CTN81/SC2/GT7 se desarrolla actualmente el borrador de la norma Pr UNE 81651 a tal fin. Desde el Dtº. de Ing. de la Construcción de la Universidad de Alicante, varios miembros del grupo de trabajo han desarrollado, contando con la experiencia en otros sistemas de protección, algunos modelos numéricos con elementos finitos para valorar y cuantificar variables

  5. Un modelo de redes neuronales para complementariedad no lineal

    Directory of Open Access Journals (Sweden)

    Favián Arenas

    2016-01-01

    Full Text Available En este artí ulo presentamos un modelo de red neuronal para resolver el problema de omplementariedad no lineal. Para ello, reformulamos este problema omo uno de minimiza ión sin restri iones usando una familia uniparamétri a de fun iones de omplementariedad. Demostramos resultados de existen ia y onvergen ia de la traye toria de la red neuronal, así omo resultados de estabilidad en el sentido de Lyapunov, estabilidad asintóti a y exponen ial. Además, presentamos resultados numéri os preliminares que ilustran un buen desempeño prá ti o del modelo.

  6. El uso de la teoría de redes sociales en la representación y análisis de textos. De las redes semánticas al análisis de redes textuales

    Directory of Open Access Journals (Sweden)

    JOAN MIQUEL VERD PERICÁS

    2005-01-01

    Full Text Available El artículo revisa el conjunto de aproximaciones al análisis de textos que se han inspirado en la teoría de redes sociales. Estas aproximaciones se agrupan en torno a dos orientaciones principales: aquellas que buscan fundamentalmente la representación y análisis de las palabras presentes en un texto dejando en una posición secundaria el tipo de relación que las une, y aquellas que otorgan la misma importancia tanto a las palabras que conforman el texto como al tipo de relaciones que las vinculan y les dan sentido semántico. El primer tipo deaproximación, que se ha denominado análisis de redes de palabras, es el más extendido, y presenta algunos inconvenientes que el segundo tipo de análisis -que se ha denominado análisis de redes textuales- intenta resolver.

  7. Artificial intelligence in cardiology

    Directory of Open Access Journals (Sweden)

    Srishti Sharma

    2017-01-01

    Full Text Available Artificial intelligence (AI provides machines with the ability to learn and respond the way humans do and is also referred to as machine learning. The step to building an AI system is to provide the data to learn from so that it can map relations between inputs and outputs and set up parameters such as “weights”/decision boundaries to predict responses for inputs in the future. Then, the model is tested on a second data set. This article outlines the promise this analytic approach has in medicine and cardiology.

  8. Is Intelligence Artificial?

    OpenAIRE

    Greer, Kieran

    2014-01-01

    Our understanding of intelligence is directed primarily at the level of human beings. This paper attempts to give a more unifying definition that can be applied to the natural world in general. The definition would be used more to verify a degree of intelligence, not to quantify it and might help when making judgements on the matter. A version of an accepted test for AI is then put forward as the 'acid test' for Artificial Intelligence itself. It might be what a free-thinking program or robot...

  9. Bayesian artificial intelligence

    CERN Document Server

    Korb, Kevin B

    2010-01-01

    Updated and expanded, Bayesian Artificial Intelligence, Second Edition provides a practical and accessible introduction to the main concepts, foundation, and applications of Bayesian networks. It focuses on both the causal discovery of networks and Bayesian inference procedures. Adopting a causal interpretation of Bayesian networks, the authors discuss the use of Bayesian networks for causal modeling. They also draw on their own applied research to illustrate various applications of the technology.New to the Second EditionNew chapter on Bayesian network classifiersNew section on object-oriente

  10. Uncertainty in artificial intelligence

    CERN Document Server

    Kanal, LN

    1986-01-01

    How to deal with uncertainty is a subject of much controversy in Artificial Intelligence. This volume brings together a wide range of perspectives on uncertainty, many of the contributors being the principal proponents in the controversy.Some of the notable issues which emerge from these papers revolve around an interval-based calculus of uncertainty, the Dempster-Shafer Theory, and probability as the best numeric model for uncertainty. There remain strong dissenting opinions not only about probability but even about the utility of any numeric method in this context.

  11. Mechanism of artificial heart

    CERN Document Server

    Yamane, Takashi

    2016-01-01

    This book first describes medical devices in relation to regenerative medicine before turning to a more specific topic: artificial heart technologies. Not only the pump mechanisms but also the bearing, motor mechanisms, and materials are described, including expert information. Design methods are described to enhance hemocompatibility: main concerns are reduction of blood cell damage and protein break, as well as prevention of blood clotting. Regulatory science from R&D to clinical trials is also discussed to verify the safety and efficacy of the devices.

  12. 7 usos del análisis de redes en la intervención comunitaria

    Directory of Open Access Journals (Sweden)

    Isidro Maya Jariego

    2016-06-01

    Full Text Available El análisis y la visualización de redes se integran de múltiples maneras en la intervención social y comunitaria. En esta revisión describimos siete usos específicos de las redes en el diseño, implementación y evaluación de programas, la dinamización comunitaria, y las campañas de prevención y promoción de la salud. En función de la estrategia de intervención, distinguimos (a la selección de agentes de salud, (b la segmentación de grupos en campañas de difusión de mensajes de prevención y promoción, (c las coaliciones comunitarias, (d el uso de la visualización de redes en dinámicas participativas de investigación-acción, (e la intervención en grupos de auto-ayuda, (f las encuestas comunitarias de redes personales y (g el análisis de la interacción informal entre participantes o aplicadores en la implementación de programas. En cada caso describimos las características de la estrategia de intervención y resumimos las principales aplicaciones de las técnicas de análisis y representación gráfica de redes. Estas siete estrategias se resumen en tres funciones del análisis de redes en la intervención comunitaria: traducción relacional de conceptos, mejora de la efectividad a través de la interacción social, y herramienta de intervención por sí misma

  13. Redes sociales como facilitadoras del aprendizaje de ciencias exactas en la educación superior

    Directory of Open Access Journals (Sweden)

    Irma Leticia Chávez Márquez

    2015-10-01

    Full Text Available El uso de las redes sociales se ha generalizado en todos los ámbitos, y el sector educativo no es la excepción. El objetivo del trabajo que aquí presentamos es relacionar el uso de las redes sociales con el aprendizaje de las ciencias exactas en una institución de educación superior, en particular con alumnos del área administrativa. Se trata de una investigación no experimental, descriptiva, transaccional y de tipo mixto. La metodología se basa en la planteada por Sandoval-Almazán, Romero-Romero y Heredia-Rodríguez (2013. La muestra aleatoria se tomó de acuerdo con el número de alumnos inscritos en tres materias de ciencias exactas: Estadística, Métodos cuantitativos 1 y Métodos cuantitativos 2; consideramos únicamente a los alumnos registrados en grupos en los cuales pueden utilizar redes sociales en clase. Llevamos a cabo una correlación y validación con el coeficiente alfa de Cronbach. Los resultados apoyan la hipótesis planteada: las redes sociales facilitan el aprendizaje, ya que 99% de los alumnos hacen uso de redes sociales en clase, elaboran trabajos y tareas y comparten información relacionada, y han explicado algún tema a través de dichas redes “mucho” o “frecuentemente”. El dispositivo más común para acceder a alguna red social en clase es el teléfono móvil. La red social utilizada en mayor medida es WhatsApp, seguida por Facebook.

  14. Redes sociales y proyección de imagen : el caso de Turisme Barcelona

    OpenAIRE

    Fondevila Gascón, Joan Francesc; Mir Bernal, Pedro; Muñoz González, Mónica

    2016-01-01

    El fenómeno de las redes sociales ocupa una posición clave dentro de las estrategias de marketing empresarial. El Turismo, un sector especialmente propenso a la actividad digital y líder en facturación de comercio electrónico, la toma de decisión depende cada vez más de las opiniones recabadas en medios sociales y, sobre todo, en redes sociales. En la presente investigación, siguiendo la metodología del estudio de caso, se analizan los perfiles de una entidad público-privada, T...

  15. Sistema de comercio electrónico basado en redes sociales

    OpenAIRE

    Castillo Hernández, Saúl

    2016-01-01

    En los últimos años, Internet ha cambiado la forma de hacer negocios ya que se ha establecido como una herramienta eficiente para encontrar productos, llegar a nuevos clientes, así como para administrar negocios de todos tamaños. Por otro lado, las redes sociales basadas en Internet (o redes sociales virtuales) han enriquecido la forma y el alcance de las relaciones humanas ya que se han consolidado como un medio efectivo y casi ubicuo para la diseminación de la información generada por s...

  16. Seguridad para protocolos MAC cooperativos en redes de sensores inalámbricas

    OpenAIRE

    Casabona Gómez, Daniel; Leiva Martín, Daniel

    2009-01-01

    Las redes de sensores inalámbricas han emergido como la tecnología que nos permite optimizar aplicaciones tan importantes como el control de la contaminación, el regadio eficiente, efectivo o la monitorización continua de señales vitales del paciente y muchas más aplicaciones. Los protocolos basados en cooperación entre nodos permiten reducir la energía consumida por los nodos sensores y, por tanto, alargar la vida útil de los mismos. Por sus características especiales, las redes de sensores ...

  17. Convivência de gerações em redes óticas PON

    OpenAIRE

    Lopes, Hugo Borges dos Santos

    2012-01-01

    O tremendo crescimento da Internet e o consumo de novos conteúdos tem levado os operadores de telecomunicações a apostar fortemente nas redes óticas passivas de acesso. Esta aposta tem como objetivo atingir um maior número e diversidade de utilizadores, bem como aumentar a capacidade e alcance das redes existentes, e diminuir o seu custo. A intensificação dos trabalhos nesta área conduziu a um aumento das atividades de investigação nesta área, que levaram à criação de várias normas. Ao lon...

  18. Modelado de redes de Petri con retroalimentación de activación

    OpenAIRE

    López Eslava, Eduardo

    2016-01-01

    Muchos sistemas no pueden ser descritos por ecuaciones diferenciales, sistemas en los cuales la ocurrencia de algún evento puede llevar al sistema de un estado a otro, y en los cuales un evento puede ocurrir abruptamente o en un instante de tiempo indeterminado. Las redes de Petri son una herramienta matemática y gráfica para sistemas que presentan este tipo de características. El carácter visual de las redes de Petri nos permite observar el flujo de comportamiento de un sistema en cada una d...

  19. Auditoría y control de redes inalámbricas

    OpenAIRE

    Arnaiz Rubio, Daniel

    2015-01-01

    En este proyecto se realizará un estudio teórico de los diferentes tipos de redes inalámbricas que existen actualmente. Centrándose principalmente en las más habituales, las redes inalámbricas de tipo local que son las que utilizamos en casa o en el trabajo. Estudiaremos en detalle sus características, sus diferentes posibilidades, así como sus vulnerabilidades y qué podemos hacer para conseguir una red lo más segura posible. Además, describiremos los distintos mecanismos...

  20. Técnicas estadísticas en análisis de redes sociales

    OpenAIRE

    Ríos Alcobendas, Gaspar

    2017-01-01

    El gran auge de las tecnologías de la comunicación ha supuesto un gran cambio en la forma en que seres humanos nos relacionamos. En particular nos hemos acogido notoriamente al uso de redes sociales, en las cuales nos relacionamos virtualmente emulando la vida real. Es por esto que, con el propósito de conocer un poco más el comportamiento de los usuarios resulta de gran interés la aplicación de técnicas estadísticas en redes sociales. En la introducción del trabajo hablamos...

  1. Los mecanismos de lo político en las redes sociales de Internet

    Directory of Open Access Journals (Sweden)

    Luis César Torres Nabel

    2013-07-01

    Full Text Available El artículo propone una serie de mecanismos sociales que operan en acontecimientos políticos en las redes sociales de Internet. Dichos mecanismos son: el contagio social, las cascadas de información y la información desregulada. Con estos elementos y valiéndose de un buen número de hechos contemporáneos que le han dando interés al fenómeno político de las redes sociales, se analiza el impacto de las mismas bajo parámetros claros que sirvan para dar explicaciones desde las ciencias sociales.

  2. Adolescentes y violencia de género en las redes sociales

    OpenAIRE

    Tarriño Concejero, Lorena; García-Carpintero Muñoz, Mª Ángeles

    2014-01-01

    El objetivo de este trabajo es analizar la influencia de las redes sociales en la Violencia de Género en adolescentes y jóvenes. Este estudio se plantea conocer y revisar la violencia de género que se promueve en las redes sociales de más auge actualmente. Las consecuencias que tienen en las personas que la padecen y su impacto en la salud. Analizaremos la intervención enfermera en estos fenómenos emergentes en la población joven y adolescentes. Para dimensionar el fenómeno ...

  3. Cosificación de las adolescentes en las redes sociales digitales

    OpenAIRE

    Urdangarin Aranbarri, Garazi

    2015-01-01

    La cosificación se refiere a la representación de una mujer a través de su cuerpo o partes de éste. La utilización masiva por parte de adolescentes de las Redes Sociales Digitales, hacen de éste fenómeno una forma tangible de discriminación sexista. Este estudio, tiene como objetivo analizar la cosificación de las adolescentes en las redes sociales y su influencia en la autoestima de cada joven. Para ello, se han aplicado diferentes escalas a 1087 adolescentes de 11 centros edu...

  4. Búsqueda de información y redes sociales: el caso de la universidad

    OpenAIRE

    Fondevila-Gascón, Joan-Francesc; del Olmo-Arriaga, Josep Lluís; Sierra Sánchez, Javier

    2012-01-01

    Las redes sociales están convirtiéndose en un actor principal en el proceso de búsqueda de información. La elección de Universidad es uno de los procesos de decisión que están siendo condicionados por el fenómeno de las redes sociales. Como reflejo del carácter conversacional y descentralizado de Internet, el universo 2.0, aprovechando las ventajas de la Sociedad de la Banda Ancha, se está constituyendo para los estudiantes como una de las principales vías de información. ...

  5. De la movilización ciberactivista a una biopolítica de las redes

    OpenAIRE

    Condorelli, Antonino; Gambetta, Leticia

    2016-01-01

    Este artículo propone la subsunción del concepto de ciberactivismo -que se reduce al uso estratégico de las tecnologías digitales para movilizaciones políticas- en el de biopolítica digital, entendida como producción incesante de lo común en y por las redes. Para operar ese desplazamiento conceptual, se dialoga con las principales concepciones de ciberactivismo y se defiende que, si bien esas visiones ayudan a comprender cómo las redes facilitaron la emergencia de una cultura general de la mo...

  6. A rede social e os tipos de apoio recebidos por idosos institucionalizados

    OpenAIRE

    Rodrigues,Adriana Guimarães; Silva,Ailton Amélio da

    2013-01-01

    Estudo descritivo que teve como objetivo identificar a composição da rede de apoio social de idosos institucionalizados, bem como os tipos e as quantidades de apoios recebidos por eles. O apoio social tem função importante no enfretamento das perdas e limitações da velhice. Participaram 30 idosos institucionalizados com média de idade de 74 anos. Foram aplicadas entrevistas e a escala de apoio social para identificar a composição da rede social e tipos de apoio social que os idosos recebiam. ...

  7. Análisis de información de redes sociales (Twitter)

    OpenAIRE

    Urrutia Sepúlveda, Angélica; Nicolás, Carolina

    2017-01-01

    El vertiginoso desarrollo de la tecnología y con ello la globalización del conocimiento, ha generado un alto interés de las redes sociales en las organizaciones, y su presencia se ha multiplicado exponencialmente en los últimos años. Es por ello, que aquí se propone analizar los datos extraídos de redes sociales, específicamente Twitter, con la finalidad de obtener diferentes elementos que permitan la gestión y el análisis relacionado con las opiniones que los usuarios proporcionan sobre las ...

  8. Práticas discursivas acerca da sexualidade humana na rede municipal de ensino do Recife

    OpenAIRE

    de Melo Oliveira, Simone

    2010-01-01

    Embasada nos pressupostos de Michel Foucault buscamos analisar práticas discursivas acerca da sexualidade humana na Rede Municipal de Ensino do Recife RMER. Consideramos que ao tomarmos o ideário foucaultiano para analisar como o discurso sobre sexualidade acontece numa rede de ensino, este pode concorrer para sabermos como uma prática educativa viabiliza o projeto de cidadania e sociedade propagado em seu discurso. A intenção foi investigar como a sexualidade tem sido tratada na RMER por m...

  9. Boas práticas no recrutamento especializado nas redes sociais

    OpenAIRE

    Silva, Marlene

    2011-01-01

    O processo de Recrutamento tem sofrido alterações, tornando-se mais sofisticado, envolvendo toda a organização e também a toda a comunidade. Para além das fontes de recrutamento tradicionais (jornais, universidades, escolas, entre outros), assistimos à utilização das redes sociais enquanto fonte de potenciais candidatos e futuros colaboradores. Com a Web 2.0, através das redes sociais, surgiu uma forma ainda mais fácil para as organizações conseguirem atrair potenciais colaboradores, oferecen...

  10. El papel de las redes en los procesos de migración interna

    OpenAIRE

    Recaño Valverde, Joaquín

    2002-01-01

    En estas líneas realizamos una presentación de los tres artículos que componen este dossier y una breve introducción sobre las redes migratorias. Una primera versión de estos textos fue expuesta en la sesión paralela: “Las redes migratorias en los procesos de migración interna” que organicé en el VI Congreso Internacional de la ADEH celebrado en Castelo-Branco en abril de 2001.

  11. Identificación de la fuente en ficheros multimedia de redes sociales

    OpenAIRE

    Rodríguez Franco, Guillermo

    2016-01-01

    El impacto en la vida cotidiana que tiene el uso de dispositivos móviles para capturar imágenes digitales alimentó un creciente interés en compartir fotos y vídeos a través de las redes sociales. Desde un punto de vista forense, los usuarios de Internet, y en especial de estas redes sociales, dejan continuamente rastros visuales de su presencia en Internet, ofreciendo una valiosa información útil para las investigaciones. Las herramientas de análisis forense de imágenes digitales permiten ...

  12. Aprendizagem Organizacional, Teoria Ator-Rede e Estudos Foucaultianos: Tempo, Espaço e Poder

    OpenAIRE

    Bruno Luiz Américo

    2016-01-01

    Esse trabalho baseia-se no mapeamento de lacunas encontradas nos desenvolvimentos dos estudos organizacionais de conhecimento e aprendizagem, e busca contribuir para a consolidação da aprendizagem organizacional como uma teoria do movimento organizacional/social. Para isso, propõe diálogo entre a Perspectiva Social-Política da Aprendizagem social, a Teoria Ator-Rede e os estudos foucaultianos. O trabalho conclui destacando o potencial da teoria ator-rede e dos estudos foucaultianos para anali...

  13. Wi-Fi Salvador: mapeamento colaborativo e redes sem fio no Brasil

    OpenAIRE

    Lemos, André; Pastor, Leonardo; Oliveira, Nelson

    2012-01-01

    O trabalho faz uma breve demonstração de políticas públicas para inclusão digital por meio da disponibilização do acesso à internet por meio de redes sem fio e discute a forma como as pessoas se relacionam com os lugares, de acordo com a existência ou inexistência de acessibilidade à internet. O objetivo é discutir o acesso à internet pelas redes sem fio no Brasil e, mais especificamente, na cidade de Salvador. Este trabalho é fruto de pesquisa realizada no âmbito do Grupo de Pesquisa em Cibe...

  14. Dinâmica de redes de osciladores de Fitzhugh-Nagumo

    OpenAIRE

    Santos, Juliana Vicente dos

    2013-01-01

    O modelo de Fitzhugh-Nagumo é composto originalmente por um sistema de duas equações diferenciais não-lineares, que simulam o comportamento de condução do impulso nervoso através da membrana neural. Neste trabalho estudamos numericamente o comportamento dinâmico de redes de neurônios acoplados, modeladas pelas equações de Fitzhugh-Nagumo. Consideramos redes de dois, três e quatro neurônios acoplados unidirecionalmente e bidirecionalmente, para as quais foram construídos espaços de parâmetros ...

  15. Estudios de mecanismos de seguridad en redes inalámbricas de sensores

    OpenAIRE

    Chivite Fernández, Patricia

    2010-01-01

    Este proyecto fin de carrera va a consistir en el estudio de los mecanismos para proveer seguridad en redes de sensores inalámbricas. En concreto, sobre redes de sensores Crossbow imote2®. Los principales sistemas de seguridad manejan diferentes mecanismos de cifrado y autentificación, así como mecanismos de detección de intrusión. En este marco de trabajo, la gestión de claves de cifrado y firma digital, así como los algoritmos criptográficos, los protocolos de autenticación y los mecanismos...

  16. Protocolos para redes inalámbricas de tiempo real: simulaciones y ensayos experimentales

    OpenAIRE

    Alimenti, Omar; Friedrich, Guillermo Rodolfo; Reggiani, Guillermo; Cayssials, Ricardo; Galasso, Christian L.; Gomez de Marco, Damián; Maidana, Federico; Tonietti, Santiago

    2012-01-01

    En el estudio de distintas propuestas tendientes a mejorar los protocolos de redes de datos, la simulación es una técnica muy valiosa para la evaluación del desempeño. El simulador Network Simulator ns-2 [1] es uno de los referentes utilizados en los trabajos de investigación en el campo de las redes de datos. Por otra parte, para la implementación práctica de los mecanismos desarrollados, se requiere de hardware específico para tal fin. La idea básica consiste en que, en función de las...

  17. Sistema automatizado para el control de las inversiones en las redes eléctricas.

    OpenAIRE

    Maylín Díaz Pardillo; María Ela Díaz Gómez; Orlando Brunet Arias

    2015-01-01

    El presente trabajo investigativo abarca las etapas de la automatización del proceso de control en la ejecución de las inversiones que se realizan en las redes del Sistema Electroenergético Nacional, integrado al Sistema Integral de Gestión de Redes de la Unión Eléctrica. Para el desarrollo de la aplicación se llevaron a cabo las etapas del proceso de desarrollo de software, según lo especifica el Proceso Unificado de Desarrollo (RUP), utilizándose como herramienta de modelado para el análisi...

  18. Las redes sociales en línea no son adictivas

    OpenAIRE

    Carbonell, Xavier; Oberst, Ursula

    2015-01-01

    En los últimos años se ha producido a un incremento notable de las publicaciones sobre posibles adicciones conductuales y tecnológicas. Entre ellas, el uso adictivo de los medios sociales ha generado un notable interés debido, fundamentalmente, al uso que hacen de los mismos los adolescentes. Los adolescentes utilizan las redes sociales para la construcción de su identidad social y de género. Para los adolescentes de hoy, las redes sociales están tan intrínsecamente tejidas en la trama de sus...

  19. Riesgo de adicción a redes sociales, autoestima y autocontrol en estudiantes de secundaria

    OpenAIRE

    Challco Huaytalla, Katherine Patricia; E.P. de Psicología; Rodríguez Vega, Sheila; Jaimes Soncco, Jania

    2016-01-01

    Objetivo: determinar la relación entre el riesgo de adicción a redes sociales, la autoestima y el autocontrol enestudiantes de 4to y 5to año del nivel secundario de una institución educativa pública de Lima Metropolitana.Material y métodos: La muestra estuvo conformada por 135 estudiantes con edades entre 14 y 16 años. Losinstrumentos utilizados fueron el Cuestionario de Adicción a Redes Sociales (CARS), el Cuestionario deAutoestima de Coopersmith y el Cuestionario de Autocontrol Infantil y A...

  20. Potências emergentes na ordem de redes: o caso do Brasil

    Directory of Open Access Journals (Sweden)

    Daniel Flemes

    2014-12-01

    Full Text Available Na última década, mudanças e inovações foram introduzidas nas redes intergovernamentais de política externa. Novas potências como Brasil adquiriram um peso relativo devido ao seu novo status atuando como definidor de agendas, moderador e construtor de coalizões. Esse artigo examina a relevância de diferentes redes de política externa como o Fórum Índia-Brasil-África do Sul (IBAS e Brasil-África do Sul-Índia-China (BASIC para a política externa brasileira desde 2003.

  1. O amor em tempos de internet: as expectativas amorosas na rede social Badoo

    OpenAIRE

    Xavier, Maria Rita Pereira

    2014-01-01

    A pesquisa propõe-se a analisar o fenômeno dos relacionamentos amorosos através da observação da Rede Social Badoo. Como meio para atingir este objetivo, foram realizadas entrevistas qualitativas em profundidade on-line. O principal questionamento é entender como se configuram as expectativas amorosas na modernidade líquida. Agregado a isto ainda há como categorias de análise a visão sobre relacionamentos e as experiências amorosas proporcionadas pelo uso da Rede Social Badoo. ...

  2. Redes sociales, políticas públicas y capital social

    OpenAIRE

    Lluís Ballester; Belén Pascual; Carlos Vecina

    2014-01-01

    La comunidad, o en un espacio más amplio la propia sociedad, en cualquiera de sus dimensiones, no es un espacio cerrado sin conexiones e interconexiones; más bien puede concebirse como una red de relaciones. En este sentido, desde las Ciencias Sociales ha ido creciendo el interés por el estudio de las redes sociales; esto ha permitido comprender mejor como se construyen y mantienen las relaciones sociales entre la población. Junto al concepto de redes sociales aparece también el de capital...

  3. MODELO DE CLASIFICACIÓN DE OPINIONES SUBJETIVAS EN REDES SOCIALES

    OpenAIRE

    Tapia Perales, Miluska Rosangela; Universidad Señor de Sipán; Ruiz Montalvo, Osmar Niels; Universidad Señor de Sipán; Chirinos Mundaca, Carlos Alberto; Universidad Señor de Sipán

    2015-01-01

    El proyecto “modelo de clasificación de opiniones subjetivas en redes sociales”, aplica técnicas de Minería de datos para interpretar la opinión subjetiva (favorable o desfavorable) de los usuarios en las redes sociales que realizan en su actividad cotidiana (publicaciones) para analizar tendencias de un determinado producto, servicio o persona que sirva para la aplicación de marketing a fin de generar ventajas competitivas haciendo el uso de la analítica en la web 2.0.  El Modelo usa técnica...

  4. En busca del contenido de las redes sociales : los "motivos" de las relaciones

    OpenAIRE

    Bidart, Claire

    2009-01-01

    Este artículo propone devolverle a la relación social su importancia como unidad básica de las redes sociales, y explorar lo que constituye su “sustancia” considerada aquí como el “motivo” de las relaciones. Las redes relacionales de un panel de jóvenes fueron construidas a partir de una investigación longitudinal que los sigue desde hace 12 años, interrogándolos cada tres años. Se recogieron datos sobre todas las personas frecuentadas en los distintos contextos de vida y sobre la calidad de ...

  5. Interacción del informativo local de COPE Ondanaranja con las redes sociales.

    OpenAIRE

    FERNÁNDEZ MOLTÓ, NOELIA

    2013-01-01

    Este proyecto se basa en conocer la interacción del informativo local de la emisora COPE Onda Naranja Radio Safor-Valldigna con las redes sociales mediante el análisis del formato informativo que ofrece y la influencia que incide desde las redes sociales como Facebook y Twitter en la elección de los temas a tratar, la investigación y el análisis semanal de las encuestas on-line y las épocas de mayor interés para el internauta/oyente; el objetivo principal no podía ser otro que la investigació...

  6. Las redes sociales y la competencia digital en educación primaria

    OpenAIRE

    Irazábal, Raquel

    2012-01-01

    Con el presente trabajo pretendo justificar como las Tecnologías de la Información y la Comunicación han de estar presentes en nuestro sistema educativo. Para ello realizo un análisis sobre la situación de la normativa vigente, especialmente de la competencia digital, a través de la cual analizaré tanto el uso de las TIC, como de las redes sociales en el aula. Tanto Internet como las redes sociales las debemos entender como un campo abierto a la reflexión y la investigación, de ahí su impo...

  7. How to teach artificial organs.

    Science.gov (United States)

    Zapanta, Conrad M; Borovetz, Harvey S; Lysaght, Michael J; Manning, Keefe B

    2011-01-01

    Artificial organs education is often an overlooked field for many bioengineering and biomedical engineering students. The purpose of this article is to describe three different approaches to teaching artificial organs. This article can serve as a reference for those who wish to offer a similar course at their own institutions or incorporate these ideas into existing courses. Artificial organ classes typically fulfill several ABET (Accreditation Board for Engineering and Technology) criteria, including those specific to bioengineering and biomedical engineering programs.

  8. Artificial Photosynthesis: Beyond Mimicking Nature

    International Nuclear Information System (INIS)

    Dau, Holger; Fujita, Etsuko; Sun, Licheng

    2017-01-01

    In this Editorial, Guest Editors Holger Dau, Etsuko Fujita, and Licheng Sun introduce the Special Issue of ChemSusChem on “Artificial Photosynthesis for Sustainable Fuels”. Here, they discuss the need for non-fossil based fuels, introduce both biological and artificial photosynthesis, and outline various important concepts in artificial photosynthesis, including molecular and solid-state catalysts for water oxidation and hydrogen evolution, catalytic CO 2 reduction, and photoelectrochemical systems.

  9. Artificial Intelligence in Space Platforms.

    Science.gov (United States)

    1984-12-01

    computer algorithms, there still appears to be a need for Artificial Inteligence techniques in the navigation area. The reason is that navigaion, in...RD-RI32 679 ARTIFICIAL INTELLIGENCE IN SPACE PLRTFORNSMU AIR FORCE 1/𔃼 INST OF TECH WRIGHT-PRTTERSON AFB OH SCHOOL OF ENGINEERING M A WRIGHT DEC 94...i4 Preface The purpose of this study was to analyze the feasibility of implementing Artificial Intelligence techniques to increase autonomy for

  10. Artificial Intelligence and Moral intelligence

    OpenAIRE

    Laura Pana

    2008-01-01

    We discuss the thesis that the implementation of a moral code in the behaviour of artificial intelligent systems needs a specific form of human and artificial intelligence, not just an abstract intelligence. We present intelligence as a system with an internal structure and the structural levels of the moral system, as well as certain characteristics of artificial intelligent agents which can/must be treated as 1- individual entities (with a complex, specialized, autonomous or selfdetermined,...

  11. Trimaran Resistance Artificial Neural Network

    Science.gov (United States)

    2011-01-01

    11th International Conference on Fast Sea Transportation FAST 2011, Honolulu, Hawaii, USA, September 2011 Trimaran Resistance Artificial Neural Network Richard...Trimaran Resistance Artificial Neural Network 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e... Artificial Neural Network and is restricted to the center and side-hull configurations tested. The value in the parametric model is that it is able to

  12. Artificial Intelligence and Economic Theories

    OpenAIRE

    Marwala, Tshilidzi; Hurwitz, Evan

    2017-01-01

    The advent of artificial intelligence has changed many disciplines such as engineering, social science and economics. Artificial intelligence is a computational technique which is inspired by natural intelligence such as the swarming of birds, the working of the brain and the pathfinding of the ants. These techniques have impact on economic theories. This book studies the impact of artificial intelligence on economic theories, a subject that has not been extensively studied. The theories that...

  13. Kappe neurons, a novel population of olfactory sensory neurons.

    Science.gov (United States)

    Ahuja, Gaurav; Bozorg Nia, Shahrzad; Zapilko, Veronika; Shiriagin, Vladimir; Kowatschew, Daniel; Oka, Yuichiro; Korsching, Sigrun I

    2014-02-10

    Perception of olfactory stimuli is mediated by distinct populations of olfactory sensory neurons, each with a characteristic set of morphological as well as functional parameters. Beyond two large populations of ciliated and microvillous neurons, a third population, crypt neurons, has been identified in teleost and cartilaginous fishes. We report here a novel, fourth olfactory sensory neuron population in zebrafish, which we named kappe neurons for their characteristic shape. Kappe neurons are identified by their Go-like immunoreactivity, and show a distinct spatial distribution within the olfactory epithelium, similar to, but significantly different from that of crypt neurons. Furthermore, kappe neurons project to a single identified target glomerulus within the olfactory bulb, mdg5 of the mediodorsal cluster, whereas crypt neurons are known to project exclusively to the mdg2 glomerulus. Kappe neurons are negative for established markers of ciliated, microvillous and crypt neurons, but appear to have microvilli. Kappe neurons constitute the fourth type of olfactory sensory neurons reported in teleost fishes and their existence suggests that encoding of olfactory stimuli may require a higher complexity than hitherto assumed already in the peripheral olfactory system.

  14. Artificial Enzymes, "Chemzymes"

    DEFF Research Database (Denmark)

    Bjerre, Jeannette; Rousseau, Cyril Andre Raphaël; Pedersen, Lavinia Georgeta M

    2008-01-01

    Enzymes have fascinated scientists since their discovery and, over some decades, one aim in organic chemistry has been the creation of molecules that mimic the active sites of enzymes and promote catalysis. Nevertheless, even today, there are relatively few examples of enzyme models that successf......Enzymes have fascinated scientists since their discovery and, over some decades, one aim in organic chemistry has been the creation of molecules that mimic the active sites of enzymes and promote catalysis. Nevertheless, even today, there are relatively few examples of enzyme models...... that successfully perform Michaelis-Menten catalysis under enzymatic conditions (i.e., aqueous medium, neutral pH, ambient temperature) and for those that do, very high rate accelerations are seldomly seen. This review will provide a brief summary of the recent developments in artificial enzymes, so called...... "Chemzymes", based on cyclodextrins and other molecules. Only the chemzymes that have shown enzyme-like activity that has been quantified by different methods will be mentioned. This review will summarize the work done in the field of artificial glycosidases, oxidases, epoxidases, and esterases, as well...

  15. The total artificial heart.

    Science.gov (United States)

    Cook, Jason A; Shah, Keyur B; Quader, Mohammed A; Cooke, Richard H; Kasirajan, Vigneshwar; Rao, Kris K; Smallfield, Melissa C; Tchoukina, Inna; Tang, Daniel G

    2015-12-01

    The total artificial heart (TAH) is a form of mechanical circulatory support in which the patient's native ventricles and valves are explanted and replaced by a pneumatically powered artificial heart. Currently, the TAH is approved for use in end-stage biventricular heart failure as a bridge to heart transplantation. However, with an increasing global burden of cardiovascular disease and congestive heart failure, the number of patients with end-stage heart failure awaiting heart transplantation now far exceeds the number of available hearts. As a result, the use of mechanical circulatory support, including the TAH and left ventricular assist device (LVAD), is growing exponentially. The LVAD is already widely used as destination therapy, and destination therapy for the TAH is under investigation. While most patients requiring mechanical circulatory support are effectively treated with LVADs, there is a subset of patients with concurrent right ventricular failure or major structural barriers to LVAD placement in whom TAH may be more appropriate. The history, indications, surgical implantation, post device management, outcomes, complications, and future direction of the TAH are discussed in this review.

  16. THRESHOLD LOGIC IN ARTIFICIAL INTELLIGENCE

    Science.gov (United States)

    COMPUTER LOGIC, ARTIFICIAL INTELLIGENCE , BIONICS, GEOMETRY, INPUT OUTPUT DEVICES, LINEAR PROGRAMMING, MATHEMATICAL LOGIC, MATHEMATICAL PREDICTION, NETWORKS, PATTERN RECOGNITION, PROBABILITY, SWITCHING CIRCUITS, SYNTHESIS

  17. Stochastic neuron models

    CERN Document Server

    Greenwood, Priscilla E

    2016-01-01

    This book describes a large number of open problems in the theory of stochastic neural systems, with the aim of enticing probabilists to work on them. This includes problems arising from stochastic models of individual neurons as well as those arising from stochastic models of the activities of small and large networks of interconnected neurons. The necessary neuroscience background to these problems is outlined within the text, so readers can grasp the context in which they arise. This book will be useful for graduate students and instructors providing material and references for applying probability to stochastic neuron modeling. Methods and results are presented, but the emphasis is on questions where additional stochastic analysis may contribute neuroscience insight. An extensive bibliography is included. Dr. Priscilla E. Greenwood is a Professor Emerita in the Department of Mathematics at the University of British Columbia. Dr. Lawrence M. Ward is a Professor in the Department of Psychology and the Brain...

  18. Improvement of the detection response time of gas sensors using the association of artificial neural networks with pattern recognition technique; Amelioration de la reponse temporelle de capteurs de gaz par reconnaissance de forme a l'aide de reseaux de neurones

    Energy Technology Data Exchange (ETDEWEB)

    Bordieu, Ch.; Rebiere, D. [Bordeaux-1 Univ., Lab. IXL, UMR CNRS 5818, 33 (France); Pistre, J.; Planata, R. [Centre d' Etudes du Bouchet, 91 - Vert-le-Petit (France)

    1999-07-01

    The association of artificial neural networks (multilayer perceptrons) with a real time pattern recognition technique (shifting windows) allowed the development of systems for the detection and the quantification of gases. Shifting window technique is presented and offers an interesting way to improve the detection response time. The partial detector characterization with regard to its parameters was realized. Applications dealing with the detection of gas compounds using surface acoustic sensors permit to show the shifting window technique feasibility. (author)

  19. Una tipología analítica de las redes de apoyo social en inmigrantes africanos en Andalucía

    OpenAIRE

    MANUEL F. MARTÍNEZ GARCÍA; MANUEL GARCÍA RAMÍREZ; ISIDRO MAYA JARIEGO

    2001-01-01

    Se elabora una clasificación de las redes de apoyo social de inmigrantes africanos en Andalucía. Para ello se empleó un análisis de conglomerados con varias variables: el tamaño, la composición, la disponibilidad, la utilización y la capacidad de la red de apoyo social. Con un grupo de 600 inmigrantes africanos, se obtuvieron cuatro categorías: pequeñas redes de compatriotas amigos; redes insuficientes; redes de tamaño medio compuestas por españoles y compatriotas amigos; redes de tamaño medi...

  20. Conectados por redes sociales : introducción al Análisis de redes sociales y casos prácticos

    OpenAIRE

    Peyró Outeiriño, Maria Belén

    2015-01-01

    El libro que vamos a reseñar, es un avance significativo en la difusión del conocimiento de las Redes Sociales, su conjunto de actores y sus vínculos relacionales, y del Análisis de Redes Sociales (ARS) como un método para medir, representar, analizar y entender los comportamientos sociales, los patrones de interacción social de los actores dentro de un determinado contexto.¿Qué información se puede estudiar mediante el ARS?, ¿En que ámbitos o áreas puede aplicarse? ¿Cómo se usa y con qué fin...

  1. REDES DE COMUNICACIÓN Y AUTOMATIZACIÓN DE SISTEMAS DE POTENCIA - UN PASO HACIA LA TECNOLOGÍA DE LAS REDES INTELIGENTES SMART GRIDS

    Directory of Open Access Journals (Sweden)

    Hernán Arturo Santana

    2013-01-01

    Full Text Available Con la continua aceptación en el sector eléctrico del estándar para las redes de comunicación y automatización de sistemas de potencia IEC 61850, es importante contar con un conocimiento básico, de porque es catalogado con el eslabón apropiado para la estandarización de la comunicación en los sistemas de potencia eléctrica, revisándolo desde su objetivos de creación, hasta los beneficios que aporta para poder contar en un futuro con redes inteligentes “Smart Grid”, igualmente describiendo cuales son los requerimientos funcionales con que debe contar una subestación eléctrica en el área de las telecomunicaciones para que pueda aportar a una red inteligente.

  2. Generative Artificial Intelligence : Philosophy and Theory of Artificial Intelligence

    NARCIS (Netherlands)

    van der Zant, Tijn; Kouw, Matthijs; Schomaker, Lambertus; Mueller, Vincent C.

    2013-01-01

    The closed systems of contemporary Artificial Intelligence do not seem to lead to intelligent machines in the near future. What is needed are open-ended systems with non-linear properties in order to create interesting properties for the scaffolding of an artificial mind. Using post-structuralistic

  3. Quando a cooperação falha: um estudo de caso sobre o fracasso de uma rede interorganizacional.

    Directory of Open Access Journals (Sweden)

    Douglas Wegner

    2012-02-01

    Full Text Available Os benefícios da cooperação interorganizacional têm sido pesquisados extensivamente pelos teóricos organizacionais, mas poucos estudos focam casos de fracasso. Apesar do grande número de redes de empresas bem-sucedidas, muitas também enfrentam dificuldades na organização e na gestão da cooperação, encerrando suas atividades sem atingir os objetivos propostos. Este artigo apresenta um caso de fracasso de uma rede de empresas do segmento supermercadista, à luz de estudos de Park e Ungson (2001, Jarillo (1988, Khanna, Gulati e Nohria (1998 e Brouthers, Brouthers e Wilkinson (1995 sobre as dificuldades na cooperação empresarial. Por meio de entrevistas em profundidade com a diretoria da rede, com empresários participantes e com a consultora que apoiou a criação da rede, identificaram-se os principais fatores que contribuíram para que a rede fosse encerrada sem atingir os resultados esperados. Os fatores foram divididos em dois grupos: pré-formalização da rede, como o perfil e a escolha dos participantes, o número de participantes da rede e a definição do momento para lançamento da rede; e pós-formalização da rede, que inclui aspectos como o surgimento de desajustes estratégicos, a perda de apoio do programa público e a falta de maturidade do grupo, que enfrentou dificuldades para gerenciar o processo de cooperação sem apoio externo. Como implicação teórica, o estudo apresenta fatores pouco explorados pela literatura e que podem levar ao fracasso da cooperação, como o número reduzido de empresas, o momento inadequado de lançamento da rede e a imaturidade do grupo. O conjunto de elementos identificado também tem implicações gerenciais: empresários e gestores de redes devem analisar cuidadosamente o perfil e o alinhamento estratégico das empresas ao constituírem a rede, a fim de evitar que eventuais diferenças se tornem um problema depois que a rede já está constituída.

  4. Neuronal Migration and Neuronal Migration Disorder in Cerebral Cortex

    OpenAIRE

    SUN, Xue-Zhi; TAKAHASHI, Sentaro; GUI, Chun; ZHANG, Rui; KOGA, Kazuo; NOUYE, Minoru; MURATA, Yoshiharu

    2002-01-01

    Neuronal cell migration is one of the most significant features during cortical development. After final mitosis, neurons migrate from the ventricular zone into the cortical plate, and then establish neuronal lamina and settle onto the outermost layer, forming an "inside-out" gradient of maturation. Neuronal migration is guided by radial glial fibers and also needs proper receptors, ligands, and other unknown extracellular factors, requests local signaling (e.g. some emitted by the Cajal-Retz...

  5. The effect of correlated neuronal firing and neuronal heterogeneity on population coding accuracy in guinea pig inferior colliculus.

    Directory of Open Access Journals (Sweden)

    Oran Zohar

    Full Text Available It has been suggested that the considerable noise in single-cell responses to a stimulus can be overcome by pooling information from a large population. Theoretical studies indicated that correlations in trial-to-trial fluctuations in the responses of different neurons may limit the improvement due to pooling. Subsequent theoretical studies have suggested that inherent neuronal diversity, i.e., the heterogeneity of tuning curves and other response properties of neurons preferentially tuned to the same stimulus, can provide a means to overcome this limit. Here we study the effect of spike-count correlations and the inherent neuronal heterogeneity on the ability to extract information from large neural populations. We use electrophysiological data from the guinea pig Inferior-Colliculus to capture inherent neuronal heterogeneity and single cell statistics, and introduce response correlations artificially. To this end, we generate pseudo-population responses, based on single-cell recording of neurons responding to auditory stimuli with varying binaural correlations. Typically, when pseudo-populations are generated from single cell data, the responses within the population are statistically independent. As a result, the information content of the population will increase indefinitely with its size. In contrast, here we apply a simple algorithm that enables us to generate pseudo-population responses with variable spike-count correlations. This enables us to study the effect of neuronal correlations on the accuracy of conventional rate codes. We show that in a homogenous population, in the presence of even low-level correlations, information content is bounded. In contrast, utilizing a simple linear readout, that takes into account the natural heterogeneity, even of neurons preferentially tuned to the same stimulus, within the neural population, one can overcome the correlated noise and obtain a readout whose accuracy grows linearly with the size of

  6. Herramientas para el análisis y seguimiento en Redes SocialesFerramentas para a Análise e Monitoramento nas Redes Sociais

    Directory of Open Access Journals (Sweden)

    Juan Prieto

    2012-01-01

    Full Text Available Introducción: Las redes y asociaciones son utilizadas por las personas desde los principios de la humanidad y su análisis emerge preocupaciones de distintos sectores de la sociedad. El Análisis de Redes Sociales estudia la relación que existe entre las personas, la estructura social, se compara la presencia online de una empresa con su debida competencia etc. Tratase de un área que está emergiendo como imprescindible en los procesos de decisión para su capacidad de analizar e intervenir en el comportamiento de la estrutucturas. Objetivo: Evaluar tres herramientas de Análisis de Redes Sociales para monitorear las conversaciones acerca de la organización “IFLA” (Federación Internacional de Asociaciones de Bibliotecarios para medir el sentimiento de las mismas, administrar los esfuerzos sociales y relacionar los flujos entre las entidades y los grupos. Metodología: Ensayo Resultados: La propiedad más importante de una herramienta para el Análisis de Redes Sociales es el echo de que son libres y virtuales. Los resultados muestran que el número de búsquedas realizadas sobre la IFLA, desde 2004, es decreciente en relación con el número total de búsquedas que han sido realizadas en Google. Por otra parte, es interesante destacar que el interés regional no coincide completamente con Google Trends y Google Insight. Conclusiones: El estudio analizó las herramientas especializadas en el registro de la actividad en las medias sociales, que tienen un alto potencial para el ejercicio del control en la esfera de las relaciones públicas y de la investigación básica y aplicada.

  7. Redes de Citação: estudo de rede de pesquisadores a partir da competência em informação

    Directory of Open Access Journals (Sweden)

    Marcos Moraes

    2015-08-01

    Full Text Available No âmbito da comunicação científica, pesquisadores vêm utilizando a metodologia de Análise de Redes Sociais (ARS a fim de investigar como ocorre o relacionamento entre pesquisadores/instituições de ensino e pesquisa, organizações e documentos. A pesquisa presente neste artigo se insere nesse contexto: o objetivo foi mapear uma rede de citação dos autores que publicaram trabalhos sobre Competência em Informação (CI na base de dados Scopus no ano de 2012. Foi utilizada a ARS em conjunto com aspectos técnicos da Análise de Citação para atingir ao objetivo proposto. A rede analisada apresentou um grau de densidade muito baixo, ou seja, houve um baixo índice de citação entre os autores; diferentemente das autocitações, que foram observadas em um número bastante alto. Foi possível constatar que determinados autores exercem grande importância por serem bastante citados pelos colegas. No caso da rede em questão, Christine Bruce foi identificada como a mais citada pelos colegas. Novas pesquisas similares podem ser realizadas se analisados outros períodos e canais de comunicação a fim de estabelecer comparações para se adensar o conhecimento sobre o comportamento dos pesquisadores dessa área.

  8. Artificial organs: recent progress in artificial hearing and vision.

    Science.gov (United States)

    Ifukube, Tohru

    2009-01-01

    Artificial sensory organs are a prosthetic means of sending visual or auditory information to the brain by electrical stimulation of the optic or auditory nerves to assist visually impaired or hearing-impaired people. However, clinical application of artificial sensory organs, except for cochlear implants, is still a trial-and-error process. This is because how and where the information transmitted to the brain is processed is still unknown, and also because changes in brain function (plasticity) remain unknown, even though brain plasticity plays an important role in meaningful interpretation of new sensory stimuli. This article discusses some basic unresolved issues and potential solutions in the development of artificial sensory organs such as cochlear implants, brainstem implants, artificial vision, and artificial retinas.

  9. Conectados por redes sociales: Introducción al Análisis de redes sociales y casos prácticos

    Directory of Open Access Journals (Sweden)

    Maria Belén Peyró Outeiriño

    2015-12-01

    Full Text Available El libro que vamos a reseñar, es un avance significativo en la difusión del conocimiento de las Redes Sociales, su conjunto de actores y sus vínculos relacionales, y del Análisis de Redes Sociales (ARS como un método para medir, representar, analizar y entender los comportamientos sociales, los patrones de interacción social de los actores dentro de un determinado contexto. ¿Qué información se puede estudiar mediante el ARS?, ¿En que ámbitos o áreas puede aplicarse? ¿Cómo se usa y con qué fines? ¿Cuál es la potencialidad del método? En los once capítulos que estructuran el libro, veintidós autores contestan a estas preguntas e introducen al lector en el estudio de las redes sociales y el análisis de la mismas desde la diversidad y amplitud en la que es posible aplicar el método, en diversos campos como la economía, sociología, ecología, biología, desarrollo sostenible, salud, comunicación, o educación.

  10. RELACIONAMENTOS INTERORGANIZACIONAIS HORIZONTAIS E FORMAÇÃO DE VALOR EM REDES DE AGRONEGÓCIOS: O CASO DE UMA REDE DE FLORICULTURAS

    Directory of Open Access Journals (Sweden)

    Heron Sergio Moreira Begnis

    2011-12-01

    Full Text Available O artigo tem como objetivo analisar o processo de formação de valor nos relacionamentos interorganizacionais horizontais (em rede no agronegócio de flores e plantas ornamentais em Santa Cruz do Sul - RS. Trata-se de um estudo de natureza qualitativa e de caráter exploratório onde o método investigativo empregado foi o estudo de caso, constituído pela Rede Aflor. A coleta dos dados operou-se por meio de entrevistas com o principal gestor de cada uma das organizações que formam essa rede. A análise do caso sustenta-se em um modelo teórico que apresenta o processo de formação de valor através do relacionamento entre organizações como sendo composto ou caracterizado pela presença e atuação de elementos de valor transacional e elementos de valor relacional. Os primeiros associados a atributos de caráter objetivo e os segundos com um maior nível de subjetividade e complexidade sendo que cooperação, confiança, compensação, comunicação, compartilhamento e comprometimento, figuram como elementos básicos da formação de valor relacional.

  11. Redes de Cooperação e Território. O Caso da Associação Rede Casanova

    Directory of Open Access Journals (Sweden)

    Goretti Feijó de Almeida, Giovana

    2015-01-01

    Full Text Available The article addresses the issue of the relationship between cooperation networks of smaller firms and territory in the context of uncertainties, difficulties, but also of market opportunities arising from economic globalization. The aim was to analyze the organizational and territorial dimension present in the process of establishment and operation of a given cooperative enterprise network, and express in speeches and in strategic and political articulations that their members nodes develop the territory in which they operate. To do so, was analyzed the case of Rede Casanova, founded in 2003, and that by 2012, was recognized as the largest network of cooperation in the construction of the Southern Brazil in number of stores associated materials segment. The study was qualitative and exploratory, involved conducting a literature review, desk research, semi-structured interviews, and analysis of primary data on the process of formation and functioning of the Association Rede Casanova. The analysis of the development of Rede Casanova allows to identify the presence of a foundational discourse, contradictory and permanent cooperation among its constituent node (companies, the existence in its service territory, the different strategies of action ranging from greater horizontal cooperation between nodes, the greater centralization and concentration of power by the central node (headquarters, the decisions regarding the choice of new members and the mode of operation and performance of the network in the market, resulting in significant changes in the your territorial organization.

  12. NARRATIVAS DA DEPENDÊNCIA NAS REDES DE APRENDIZAGEM ONLINE: Como os professores usam as redes de aprendizagem para promover a autonomia

    Directory of Open Access Journals (Sweden)

    José Lauro Martins

    2016-03-01

    Full Text Available Neste artigo analisa-se a instituição de redes de aprendizagens em ambiente virtual e a necessidade de estabelecer a dialogia como estratégia metodológica. Entende-se que a ação dialógica ocorra quando cada sujeito possa agir e/ou construir sua autonomia viabilizando sua construção nas redes de aprendizagem. Para a base empírica deste estudo, analisamos 1327 mensagens  de 5 professores em fóruns para orientação do trabalho de conclusão de um curso online com 200 alunos, distribuídos em 5 turmas.. Esta pesquisa permite-nos concluir que prevalece o perfil centralizador dos professores, comum na Educação tradicional, mesmo sendo professores experientes em Educação mediada pelas TDIC e com formação em Educação. O que confirma a necessidade de se investir na formação  de professores para a docência online, a fim de superar essa postura tradicional para que, a estratégia metodológica colaborativa e interativa das redes de aprendizagem possa ser implementada.

  13. Artificial Diets for Mosquitoes

    Directory of Open Access Journals (Sweden)

    Kristina K. Gonzales

    2016-12-01

    Full Text Available Mosquito-borne diseases are responsible for more than a million human deaths every year. Modern mosquito control strategies such as sterile insect technique (SIT, release of insects carrying a dominant lethal (RIDL, population replacement strategies (PR, and Wolbachia-based strategies require the rearing of large numbers of mosquitoes in culture for continuous release over an extended period of time. Anautogenous mosquitoes require essential nutrients for egg production, which they obtain through the acquisition and digestion of a protein-rich blood meal. Therefore, mosquito mass production in laboratories and other facilities relies on vertebrate blood from live animal hosts. However, vertebrate blood is expensive to acquire and hard to store for longer times especially under field conditions. This review discusses older and recent studies that were aimed at the development of artificial diets for mosquitoes in order to replace vertebrate blood.

  14. A programmable artificial retina

    International Nuclear Information System (INIS)

    Bernard, T.M.; Zavidovique, B.Y.; Devos, F.J.

    1993-01-01

    An artificial retina is a device that intimately associates an imager with processing facilities on a monolithic circuit. Yet, except for simple environments and applications, analog hardware will not suffice to process and compact the raw image flow from the photosensitive array. To solve this output problem, an on-chip array of bare Boolean processors with halftoning facilities might be used, providing versatility from programmability. By setting the pixel memory size to 3 b, the authors have demonstrated both the technological practicality and the computational efficiency of this programmable Boolean retina concept. Using semi-static shifting structures together with some interaction circuitry, a minimal retina Boolean processor can be built with less than 30 transistors and controlled by as few as 6 global clock signals. The successful design, integration, and test of such a 65x76 Boolean retina on a 50-mm 2 CMOS 2-μm circuit are presented

  15. Artificial intelligence in radiology.

    Science.gov (United States)

    Hosny, Ahmed; Parmar, Chintan; Quackenbush, John; Schwartz, Lawrence H; Aerts, Hugo J W L

    2018-05-17

    Artificial intelligence (AI) algorithms, particularly deep learning, have demonstrated remarkable progress in image-recognition tasks. Methods ranging from convolutional neural networks to variational autoencoders have found myriad applications in the medical image analysis field, propelling it forward at a rapid pace. Historically, in radiology practice, trained physicians visually assessed medical images for the detection, characterization and monitoring of diseases. AI methods excel at automatically recognizing complex patterns in imaging data and providing quantitative, rather than qualitative, assessments of radiographic characteristics. In this Opinion article, we establish a general understanding of AI methods, particularly those pertaining to image-based tasks. We explore how these methods could impact multiple facets of radiology, with a general focus on applications in oncology, and demonstrate ways in which these methods are advancing the field. Finally, we discuss the challenges facing clinical implementation and provide our perspective on how the domain could be advanced.

  16. Hydraulically actuated artificial muscles

    Science.gov (United States)

    Meller, M. A.; Tiwari, R.; Wajcs, K. B.; Moses, C.; Reveles, I.; Garcia, E.

    2012-04-01

    Hydraulic Artificial Muscles (HAMs) consisting of a polymer tube constrained by a nylon mesh are presented in this paper. Despite the actuation mechanism being similar to its popular counterpart, which are pneumatically actuated (PAM), HAMs have not been studied in depth. HAMs offer the advantage of compliance, large force to weight ratio, low maintenance, and low cost over traditional hydraulic cylinders. Muscle characterization for isometric and isobaric tests are discussed and compared to PAMs. A model incorporating the effect of mesh angle and friction have also been developed. In addition, differential swelling of the muscle on actuation has also been included in the model. An application of lab fabricated HAMs for a meso-scale robotic system is also presented.

  17. Artificially Engineered Protein Polymers.

    Science.gov (United States)

    Yang, Yun Jung; Holmberg, Angela L; Olsen, Bradley D

    2017-06-07

    Modern polymer science increasingly requires precise control over macromolecular structure and properties for engineering advanced materials and biomedical systems. The application of biological processes to design and synthesize artificial protein polymers offers a means for furthering macromolecular tunability, enabling polymers with dispersities of ∼1.0 and monomer-level sequence control. Taking inspiration from materials evolved in nature, scientists have created modular building blocks with simplified monomer sequences that replicate the function of natural systems. The corresponding protein engineering toolbox has enabled the systematic development of complex functional polymeric materials across areas as diverse as adhesives, responsive polymers, and medical materials. This review discusses the natural proteins that have inspired the development of key building blocks for protein polymer engineering and the function of these elements in material design. The prospects and progress for scalable commercialization of protein polymers are reviewed, discussing both technology needs and opportunities.

  18. Artificial resuspension studies

    International Nuclear Information System (INIS)

    Cooper, B.M.; Marchall, K.B.; Thomas, K.A.; Tracy, B.L.

    1990-01-01

    Artificial resuspension studies on a range of Taranaki and other major trial site soils were performed by use of a mechanical dust-raising apparatus. A cascade impactor was used to analyse airborne dust in terms of mass and 241 Am activities for particle sizes less than 7 μm. Plutonium and americium activities were found to be enhanced in the respirable fraction. Reported enhancement factors (defined as the ratio of activity concentration of the respirable fraction to that of the total soil) ranged from 3.7 to 32.5 for Taranaki soils with an average value of 6 appearing reasonable for general application in outer (plume) areas. Values close to unity were measured at major trial sites , One Tree and Tadje. Results of some experiments where uncontamined dust was raised by activities such as walking and driving over dusty ground are also presented. 7 refs., 9 tabs., 4 figs

  19. Neuronal nets in robotics

    International Nuclear Information System (INIS)

    Jimenez Sanchez, Raul

    1999-01-01

    The paper gives a generic idea of the solutions that the neuronal nets contribute to the robotics. The advantages and the inconveniences are exposed that have regarding the conventional techniques. It also describe the more excellent applications as the pursuit of trajectories, the positioning based on images, the force control or of the mobile robots management, among others

  20. Redes neuronales de expresión facial

    OpenAIRE

    Gordillo, F.; Mestas, Lilia; Castillo Parra, Gabriela; Pérez, M.A.; López, R. M.; Arana, José M.

    2017-01-01

    Introducción. La percepción de caras involucra una amplia red de conexiones entre regiones corticales y subcorticales que intercambian y sincronizan información a través de haces de sustancia blanca. Este preciso sistema de comunicación puede verse afectado tanto a través de las propias estructuras como por las vías que las conectan. Objetivos. Delimitar el sustrato neuronal que subyace a la percepción de la expresión facial y analizar los diferentes factores que participan modulando l...