In this paper, a family of models requiring proportional mean life vitalities is considered. The problem of estimation of the parameter(s) of the model is studied in two cases of known and unknown baselines along with some simulation studies to detect the adequacy of fitting. Closure and preservation properties of some ageing classes and stochastic orders are derived.

中文翻译：

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比例生命力模型的随机方面

在本文中，考虑了需要比例平均寿命生命力的一系列模型。在已知基线和未知基线的两种情况下，研究了模型参数估计的问题，并进行了一些模拟研究以检测拟合是否合适。推导了某些老化等级和随机顺序的封闭性和保存性。