The MFPT as a function of noise intensity when 0 < m < K ; (a) r = 0.1, m = 5, K = 10, τ₁ = 0.1, τ₂ = 0.1 are fixed, P takes 0.05, 0.07, 0.1, and 0.2; (b) r = 0.1, m = 5, K = 10, τ₁ = 0.1, τ₂ = 0.1 are fixed, D takes 0.01, 0.1, 0.3, and 1.