[IEEE 2017 IEEE International Conference on Environment and Electrical Engineering and 2017 IEEE Industrial and Commercial Power Systems Europe (EEEIC / I&CPS Europe) - Milan, Italy (2017.6.6-2017.6.9)] 2017 IEEE International Conference on Environment and Electrical Engineering and 2017 IEEE Industrial and Commercial Power Systems Europe (EEEIC / I&CPS Europe) - Influence of humidity on pulse shape parameters of positive corona discharges in air at DC voltage