RESUMO
This paper presents the design and development of a set of microwave exposure system based on 1.8GHz mobile RF signal. This system can work on several modulation types to do microwave exposure experiment under different specific absorption rate (SAR) and prepare the way for researches in the effect exerted by the electromagnetic signal of mobile on human health. The hardware is made up of several RF instruments, waveguide and computer, and the software introduces the accomplishment of the control system and the algorithm of control.
Assuntos
Telefone Celular , Campos Eletromagnéticos/efeitos adversos , Exposição Ambiental , Micro-Ondas/efeitos adversos , Neurônios/efeitos da radiação , Algoritmos , Simulação por Computador , Relação Dose-Resposta à Radiação , HumanosRESUMO
Mathematical models of physical systems often have parameters that must be identified from physical data. This makes the analysis of the parameter identifiability of the given model system an essential prerequisite. Thus far, several methods have been proposed for analyzing the parameter identifiability of ordinary differential equation (ODE) systems. But, to the best of our knowledge, the parameter identifiability of differential algebraic equation (DAE) systems has scarcely been analyzed as a specific topic. Traditional differential algebraic (DA) methods developed for ODE systems are often applied directly on DAE systems. These methods, however, are not always applicable, e.g., when the prime ideal condition is not satisfied by a DAE system. In this paper, we propose a novel method to analyze the identifiability of DAE systems, based on the concept of space extension, through which the algebraic and differential variables can be decoupled. Furthermore, an inherent, low-dimensional, regular ODE system can be obtained, which is the external equivalent of the original DAE system. Subsequently, the differential algebraic (DA) method can then be used to analyze the identifiability of the low-dimension ODE system. Theoretical analysis is also presented for the proposed method. Two examples, including a simplified interaction model and an isothermal reactor system, are presented to illustrate the detailed steps and effectiveness of the proposed method.
RESUMO
A decentralized model predictive controller applicable for some systems which exhibit different dynamic characteristics in different channels was presented in this paper. These systems can be regarded as combinations of a fast model and a slow model, the response speeds of which are in two-time scale. Because most practical models used for control are obtained in the form of transfer function matrix by plant tests, a singular perturbation method was firstly used to separate the original transfer function matrix into two models in two-time scale. Then a decentralized model predictive controller was designed based on the two models derived from the original system. And the stability of the control method was proved. Simulations showed that the method was effective.