4 research outputs found
Input variable selection for forecasting models
2002 IFAC15th Triennial World Congress, Barcelona, SpainThe selection of input variables plays a crucial role when modelling time series. For nonlinear models there are not well developed techniques such as AIC and other criteria that work with linear models. In the case of Short Term Load Forecasting (STLF) generalization is greatly influenced by such selection. In this paper two approaches are compared using real data from a Spanish utility company. The models used are neural networks although the algorithms can be used with other nonlinear models. The experiments show that that input variable selection affects the performance of forecasting models and thus should be treated as a generalization problem
A new concept of invariance for saturated systems
In this paper, a new concept of invariance for saturated linear systems is presented. This new notion of invariance, denoted SNS-invariance, has a number of geometrical properties that makes its use suitable for the estimation of the domain of attraction of saturated systems. The notion of SNS-domain of attraction, that serves as an estimation of the domain of attraction of a saturated system, is introduced. It is shown that, in case of single input saturated systems, any contractive set is contained in the SNS-domain of attraction. A simple algorithm that converges to the SNS-domain of attraction is presented. Some illustrative examples are given
Gesti贸n e implementaci贸n de una pasarela HTTP-OPC aplicado a una planta solar
XXVI Jornadas de Autom谩tica, Alicante-Elche, 2005El prop贸sito de este art铆culo es detallar c贸mo
conseguir un acceso eficiente a datos provenientes
de un dispositivo gen茅rico o planta industrial
situada dentro de una red local. Dicho dispositivo
debe estar conectado a un servidor OPC que
permita acceder a las distintas variables. La
situaci贸n que se intenta resolver es aquella en la
que solamente es posible acceder a las variables
de un dispositivo cualquiera desde un equipo que
est茅 necesariamente situado dentro de la misma
red local. La soluci贸n abordada en este art铆culo
se basa en la elaboraci贸n de una aplicaci贸n web
que permita proporcionar el acceso a distintos
usuarios tanto desde dentro como desde fuera
de la red a la que pertenezca la planta. Esta
soluci贸n permite tambi茅n el control remoto ya sea
de una planta industrial o cualquier otro tipo de
dispositivo haciendo uso de OPC. En concreto,
se mostrar麓a una Planta Solar sobre la que se
explicar麓an los aspectos de implementaci贸n