Of Cod Measurement Method Based On Machine Learning Research

Water component is a multiplex and complex system, there is a highly nonlinear relation between COD (chemical oxygen demand) and ultraviolet absorbance multi-spectrum information, it is a nonlinear system. For this kind of multiply independent variables system, we need to build up a complex mathematic model. Therefore, a nonlinear model should be built up by using ultraviolet absorbance multi-spectrum method, which can token water component's complexity completely.Machine Learning, which includes Artificial Neural Networks (ANN), Support Vector Machine (SVM) etc., is more powerful in resolving this problem. This paper presents several precise water COD measurement model on some new style machine learning technique. The components of this paper are listed as follow:We use ultraviolet absorbance multi-spectrum method, get the water sample's absorbance at the characteristic wavelength, build up mathematic model for this kind of water by using absorbance and COD value. This method can token more water's internal information, also can measure COD value more accurately.The characteristics of LM-BP ANN are introduced. The main course of modeling, including data processing, training controlling and model structure selecting, is proposed. The performance in case study indicates that COD measurement modeling using LM-BP ANN is an extendable and accurately method.This paper introduces the support vector machine regression forecasting method into COD measurement. The basic ideas of SVM are introduced, and the characteristics of SVM are illuminated. The SVM's parameters selection method and the representations of different models are researched. It is proved to be promising and valuable for this model with experiment results, and can solve small-sample learning problem better.This paper also introduces the design and the realization of the Ultraviolet Scanning COD online monitoring instrument's system software, including the flow designing, functional module and algorithms realization.The conclusions and the problems to be further studied are given at the end ofthe paper.