监控摄像机的可靠性
摄像机被安置在重叠网格中. 所有区域都被覆盖直到 2×2 网格失败. 每个摄像机的预期寿命是6年. 比较该系统和只有四个摄像机的系统，带有和不带有备用组件的可靠性.
structure = BooleanConsecutiveFunction[{2, 2}, {4, 4}][Array[Subscript[x, #1, #2]&, {4, 4}]];
𝒟camera = ExponentialDistribution[1 / 6];
ℱ = FailureDistribution[structure, Join@@Array[{Subscript[x, #1, #2], 𝒟camera}&, {4, 4}]];
ℱnooverlap = FailureDistribution[Subscript[x, 1] || Subscript[x, 2] || Subscript[x, 3] || Subscript[x, 4], {{Subscript[x, 1], 𝒟camera}, {Subscript[x, 2], 𝒟camera}, {Subscript[x, 3], 𝒟camera}, {Subscript[x, 4], 𝒟camera}}];
𝒟standby = StandbyDistribution[𝒟camera, {𝒟camera, 𝒟camera, 𝒟camera}, 0.9];
ℱstandby = FailureDistribution[Subscript[x, 1] || Subscript[x, 2] || Subscript[x, 3] || Subscript[x, 4], {{Subscript[x, 1], 𝒟standby}, {Subscript[x, 2], 𝒟standby}, {Subscript[x, 3], 𝒟standby}, {Subscript[x, 4], 𝒟standby}}];Plot[Evaluate@{SurvivalFunction[ℱ, t], SurvivalFunction[ℱnooverlap, t], SurvivalFunction[ℱstandby, t]}, {t, 0, 15}, Filling -> Axis, PlotLegends -> Placed[{"Consecutive", "No overlap", "Standby"}, Below]]