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Keywords: Very short-term forecasting; SVM; Markov chain model; the confidence interval. Abstract. Very short-term forecasting of wind power is important to scheduling staff's planning and wind turbine control. This paper has established a combined forecasting model based on Markov chain and support vector machine (SVM). Firstly, the SVM is used to model for wind power. Then, transition probability matrix is made based on Markov chain to modify for SVM prediction. Finally, the prediction confidence interval of combination forecasting model is given by method of fluctuation confidence interval. Verified by an example of a wind farm indicating that the combination forecasting model is better than a single SVM model on a variety of error indicators.

The aim of this research is to investigate the impact of air pollution on the population in Shanghai. The genotoxicity of extractable organic matter (EOM) from the air particles was investigated by the means of the Salmonella plate incorporation assay, rat hepatocyte unscheduled DNA repair assay, and mice micronuclei test. The airborne particles were collected in 13 locations during the summer of 1992 and winter of 1993. The crude extracts were fractionated by acid-base partitioning into acid, base and neutral fractions. The neutral fractions were further fractionated by resin-silica gel column chromatography into three subfractions. The induction of revertants with the crude extracts was higher in winter samples than in summer samples. Both indirect-acting and direct-acting mutagenicity were observed. The mutagenicity was detected with TA98, but was not detected with TA100. The mutagenic activity was the greatest in the acid, aromatic and polar fractions from summer samples. The fractions from the winter samples did not show clear differences. There was no substantial location-related variance in the mutagenic potencies of EOM, but substantial location- or time-related variances in the mutagenic potencies of the airborne particles per cubic meter air were found. While rat hepatocyte unscheduled DNA synthesis (UDS) assay revealed genotoxicity for all the samples, there was no big variance in the genotoxicity of the fractions. The mouse micronuclei test showed results similar to the UDS assay. The difference of locality did not have statistical significance.