Semi-Markov model for the Kaplan preventive repair system for water turbines with periodic inspection of the technical conditionKlaudiusz Migawa, Agnieszka Sołtysiak, Magda Czyżewska, Sylwester Borowski and Maciej WoropayMATEC Web Conf., 351 (2021) 01002DOI: https://doi.org/10.1051/matecconf/202135101002