the control of cigarette smoking can do more to improve health and prolong life than any other single action in the whole field of preventive medicine. many smokers desire to stop but need instructions and support. beside nicotine and carbon monoxide, there are a lot of carcion-genous materials in cigarettes. a positive relationship exists between cigarette smoking and lung cancer, bronchitis, ...

This paper develops two component-level control-limit preventive maintenance (PM) policies for systems subject to the joint effect of partial recovery PM acts (imperfect PM acts) and variable operational conditions, and investigates the properties of the proposed policies. The extended proportional hazards model (EPHM) is used to model the system failure likelihood influenced by both factors. S...