[IEEE 2019 International Conference "Quality Management, Transport and Information Security, Information Technologies" (IT&QM&IS) - Sochi, Russia (2019.9.23-2019.9.27)] 2019 International Conference "Quality Management, Transport and Information Security, Information Technologies" (IT&QM&IS) - Forecasting Changes in States in Social Networks and Sentiment Security Using the Principles of Percolation Theory and Stochastic Dynamics