Consulta: subjectFacets:"Dynamic models"
Registros recuperados: 3
Data/hora: 26/07/2024 22:09:01

A comparison between three different approaches to omplement a system dynamic model: an assessment by a multidisciplinary team.
Provedor de dados: Informação Tecnológica em Agricultura (Infoteca-e)
Autores: FREUA, M. C.; BARIONI, L. G.; VILAMIU, R. G. d'A.; DIAS, F. R. T.
In the last few decades, application of system dynamics models (SDM) has disseminated through the agricultural sciences. Modeling groups are now much more multidisciplinary once the models currently developed are applied to larger frameworks. The literature has been inconclusive with regard to empirical evidence of the trade-offs between different paradigms to implement SDMs. In order to gain insight on the advantages and disadvantages between the paradigms we simulated a working group environment with seven researchers coming from various educational backgrounds where they had to implement a process-based SDM and fill in a questionnaire scoring characteristics of the paradigms and implementation process. The participants were divided into three groups...
Tipo: Folhetos
Palavras-chave: Modelos agrícolas; Modelo dinâmico; Programação orientada a objetos; Agricultural models; Objected-oriented programming; Modelo Matemático; Mathematical models; Dynamic models.
Ano: 2014
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/1008307

Fast and reliable calibration of solid substrate fermentation kinetic models using advanced non-linear programming techniques
Provedor de dados: Electronic Journal of Biotechnology
Autores: Araya,M. Macarena; Arrieta,Juan J; Pérez-Correa,J. Ricardo; Biegler,Lorenz T; Jorquera,Héctor.
Calibration of mechanistic kinetic models describing microorganism growth and secondary metabolite production on solid substrates is difficult due to model complexity given the sheer number of parameters needing to be estimated and violation of standard conditions of numerical regularity. We show how advanced non-linear programming techniques can be applied to achieve fast and reliable calibration of a complex kinetic model describing growth of Gibberella fujikuroi and production of gibberellic acid on an inert solid support in glass columns. Experimental culture data was obtained under different temperature and water activity conditions. Model differential equations were discretized using orthogonal collocations on finite elements while model calibration...
Tipo: Journal article
Palavras-chave: Dynamic models; Gibberellic acid; Nonlinear models; Parameter estimation; Secondary metabolites; Solid substrate cultivation.
Ano: 2007
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582007000100005

Livestock Dynamics: An Old Problem and Some New Tools
Provedor de dados: Research in Agricultural & Applied Economics (AgEcon Searh)
Autores: MacAulay,   T. Gordon; Hertzler,   Greg.
A problem encountered in the econometric estimation of dynamic models of livestock systems is dynamic instability during simulation of models. In the case of systems where economic decisions are involved in the breeding and the slaughter of animals it is possible for parameters to be obtained which generate dynamic instability. In the paper, a simple representation of the dynamics of a livestock system is examined using techniques of dynamic analysis. The dynamic stability of such models depends fundamentally on the parameters determining the births and deaths and thus the relative flows in and out of the stock of animals. In some situations very narrow stability ranges for the values of the parameters are observed.
Tipo: Presentation
Palavras-chave: Dynamic models; Beef herd; Dynamic instability; Dynamic processes; Livestock Production/Industries.
Ano: 2000
URL: http://purl.umn.edu/123699