oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 71 )

2018 ( 97 )

2017 ( 112 )

2016 ( 160 )

Custom range...

Search Results: 1 - 10 of 53287 matches for " David; Olaya "
All listed articles are free for downloading (OA Articles)
Page 1 /53287
Display every page Item
From in vitro to in vivo Models of Bacterial Biofilm-Related Infections
David Lebeaux,Ashwini Chauhan,Olaya Rendueles,Christophe Beloin
Pathogens , 2013, DOI: 10.3390/pathogens2020288
Abstract: The influence of microorganisms growing as sessile communities in a large number of human infections has been extensively studied and recognized for 30–40 years, therefore warranting intense scientific and medical research. Nonetheless, mimicking the biofilm-life style of bacteria and biofilm-related infections has been an arduous task. Models used to study biofilms range from simple in vitro to complex in vivo models of tissues or device-related infections. These different models have progressively contributed to the current knowledge of biofilm physiology within the host context. While far from a complete understanding of the multiple elements controlling the dynamic interactions between the host and biofilms, we are nowadays witnessing the emergence of promising preventive or curative strategies to fight biofilm-related infections. This review undertakes a comprehensive analysis of the literature from a historic perspective commenting on the contribution of the different models and discussing future venues and new approaches that can be merged with more traditional techniques in order to model biofilm-infections and efficiently fight them.
Situación actual de la traducción audiovisual en Colombia
Orrego Carmona,Jeffersson David; Alarcón Penagos,Natalia; Olaya Marulanda,Claudia Lorena; Pérez Rojas,Katherin;
íkala, Revista de Lenguaje y Cultura , 2010,
Abstract: objectives: this article has two objectives: to present the general view of the current market of avt in colombia and to highlight the importance of developing further studies in this area. methodology: the methodology used included the research and reading of literature related to the subject, the implementation of surveys to different groups related to avt and their posterior analysis. results: the results showed the general lack of knowledge on this discipline and the preferences for avt modalities of the surveyed groups. it was observed that each group has a marked preference for subtitling due to specific reasons. conclusions: it was concluded that colombian translators need avt training to meet the market demands and the importance of developing further and deeper studies focused on the development of avt in colombia is highlighted.
A Review of DAN2 (Dynamic Architecture for Artificial Neural Networks) Model in Time Series Forecasting
Velásquez-Henao,Juan David; Franco-Cardona,Carlos Jaime; Olaya-Morales,Yris;
Ingeniería y Universidad , 2012,
Abstract: recently, ghiassi, saidane and zimbra [int j forecasting, vol. 21, 2005, pp. 341-362] presented a dynamic-architecture neural network for time s er ie s p re dic t io n which p er fo r ms significantly better than traditional artificial neural networks and the arima methodology. the main objective of this article is to prove that the original dan2 model can be rewritten as an additive model. we show that our formulation has several advantages: first, it reduces the total number of parameters to estimate; second, it allows estimating all the linear parameters by using ordinary least squares or ridge regression; and, finally, it improves the search for the global minimum of the error function used to estimate the model parameters. to assess the effectiveness of our approach, we estimate two models for one of the time series used as a benchmark when the original dan2 model was proposed. the results indicate that our approach is able to find models with similar or better accuracy than the original dan2.
Predicción de los precios promedios mensuales de contratos despachados en el mercado mayorista de electricidad en Colombia usando máquinas de vectores de soporte
Velásquez H,Juan David; Franco C,Carlos Jaime; Olaya M,Yris;
Cuadernos de Administración , 2010,
Abstract: forecasting electricity prices in liberalized, deregulated markets has always been considered a difficult task, due to the number of factors that govern prices and to their complexity. this article predicts the average monthly prices for colombian electricity market contracts by using a novel neural network known as the support vector machine. forecasts obtained using a multilayer perceptron are compared to forecasts obtained using an arima model. the results show that the support vector machine better captures the intrinsic dynamics of the time series and is able to make more precise forecasts considering a 12-month horizon.
Caracterización de la demanda mensual de electricidad en colombia usando un modelo de componentes no observables
Franco Cardona,Carlos Jaime; Velásquez Henao,Juan David; Olaya Morales,Yris;
Cuadernos de Administración , 2008,
Abstract: this article reports the results seen from adjusting a model of non-observable components to the monthly electrical power demand in colombia from 1995:8 to 2006:1 in order to separate the underlying tendency of the periodical component associated with the annual cycle and study its behavior. findings show that the periodical component has a stochastic behavior but such behavior does not broaden with an increased level in the series; likewise, the model indicates that the monthly growth in demand has a linear deterministic component, approximately constant during recent years, whose rises and falls have coincided with the rises and falls seen in the gdp.
Evidencias de cambios estructurales en el precio promedio mensual del petróleo del West Texas Intermediate (WTI)
Velásquez Henao,Juan David; Olaya Morales,Yris; Franco Cardona,Carlos Jaime;
Cuadernos de Administración , 2009,
Abstract: the comportment of the price of wti oil is complex, and it is characterised by rises, falls, abrupt changes and local trends. as a result, it is difficult to identify the impact of exogenous events on the market in the comportment of prices, and as these impacts cannot be easily isolated, the dynamics of the series become obscure and difficult to predict. in preliminary inspection of the natural logarithm series of the average monthly price of wti between 1986:1 and 2008:8 gives rise to suspicion of the presence of local linear trends which ended in evident changes in dynamics. in order to validate this appreciation, an algorithm was developed for research based on a recursive partitioning to detect points of occurrence of structural changes in the trend. the algorithm was used to analyse the dynamics of the series studied. the principal results: returns of prices followed a process ar (1)-garch (2, 2), and there are three statistically significant structural changes, which are explained by its specific historic events. these changes of level show the existence of local linear trends in the prices logarithm.
ANáLISIS Y PREDICCIóN DE SERIES DE TIEMPO EN MERCADOS DE ENERGíA USANDO EL LENGUAJE R
VELáSQUEZ HENAO,JUAN DAVID; OLAYA MORALES,YRIS; FRANCO CARDONA,CARLOS JAIME;
DYNA , 2011,
Abstract: time series analysis and forecasting of economic variables are central research topics in the energy field. in this paper, we review the main aspects of the r language for statistical computing, and we stress the potential usefulness for researchers and practitioners of energy markets. also, we review the main available functions for time series analysis and forecasting, and we present some example of their use.
Biología reproductiva del Liso (Rhamdia quelen) en el río Sinú, Colombia
Olaya Nieto Charles William,Hernández Rosso David Fernando,Edgar Ayarza Pérez Edgar
Acta Biológica Colombiana , 2010,
Abstract: Se estudió la biología reproductiva del Liso (Rhamdia quelen) en el río Sinú. Los individuos fueron colectados entre enero y diciembre 2005, con tallas y pesos entre 15,5-37,0 cm de longitud total (LT) y 28,0-486,0 g de peso total. Las gónadas se conservaron en solución Gilson, se utilizó la escala de Vazzoler y se estimó proporción sexual, índices de madurez sexual, época de desove, talla media de madurez sexual, diámetro de ovocitos y fecundidad. Se evaluaron 207 hembras, 130 machos y 1 indiferenciado, con proporción sexual hembra: macho de 1,6:1, diferente a lo esperado. La talla media de madurez fue estimada en 24,0 cm LT para sexos combinados, el diámetro promedio de los ovocitos fue de 963μ y la fecundidad promedio fue estimada en 26.305 ovocitos, con ecuación de mejor ajuste F = 2960,61 WG 0,88, r = 0,94, n = 125. El Liso es un pez con tipo de desarrollo ovocitario asincrónico en más de dos grupos, con desoves parciales durante todo el a o.
Charlie and the chocolate factory: adaptación y traducción
Ana María Castro Ortíz,Claudia Lorena Olaya Marulanda,Jeffersson David Orrego Carmona
Mutatis Mutandis : Revista Latinoamericana de Traducción , 2008,
Abstract: En este estudio se presenta la relación existente entre el discurso literario, el cinematográfico y el traductivo, por medio de un análisis descriptivo de algunos apartes de la obra literaria titulada "Charlie y la fábrica de chocolates", sus dos adaptaciones al cine y la subtitulación al espa ol de la segunda adaptación. De esta manera, se evidencian algunas variaciones de las características propias de los personajes que pueden influir en el mensaje transmitido en la obra literaria original.
A review of DAN2 model
Juan David Velasquez Henao,Carlos Jaime Franco Cardona,Yris Olaya Morales
Ingeniería y Universidad , 2012,
Abstract: In this paper we prove that the original DAN2 model can be rewritten as an additive model. We show that our formulation has several advantages: first, it reduces the total number of parameters to estimate; second, it allows estimating all the linear parameters using ordinary least squares or ridge regression; and, finally, it improves the search for the global minimum of the error function used to estimate the model parameters. To assess the effectiveness of our approach, we estimate two models for one of the time series used as a benchmark when the original DAN2 model was proposed. The results indicate that our approach is able to find models with similar or better accuracy than the original DAN2.
Page 1 /53287
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.