An alarm system is optimal if it detects catastrophes with a certain high probability and simultaneously gives a minimum number of false alarms. In a general context an optimal alarm system is derived and then the method is applied to Gaussian processes.
Jacques De Mare. "Optimal Prediction of Catastrophes with Applications to Gaussian Processes." Ann. Probab. 8 (4) 841 - 850, August, 1980. https://doi.org/10.1214/aop/1176994670