For a component or a system subject to stochastic degradation with sporadic jumps that occur at random times and have random sizes, we propose to model the cumulative degradation with random jumps using a single stochastic process based on the characteristics of Lévy subordinators, the class of non-decreasing Lévy processes. Based on an inverse Fourier transform, we derive a new closed-form rel...

This paper extends the theory of optimal aging and death (Dalgaard and Strulik, 2010, 2013) towards uncertain death. Specifically, it is assumed that at any age the probability to survive depends on the number of health deficits accumulated. At the expense of less analytical tractability the model provides a formal description of aging as conceptualized in modern biology, i.e. as an inherently ...

Health care administrators commonly employ two types of resource flexibilities (demand upgrades and staffing flexibility) to efficiently coordinate two critical internal resources, nursing staff and beds, and an external resource (contract nurses) to satisfy stochastic patient demand. Under demand upgrades, when beds are unavailable for patients in a less acute unit, patients are upgraded to a ...

In this work we solve completely the starting and stopping problem when the dynamics of the system are a general adapted stochastic process. We use backward stochastic differential equations and Snell envelopes. Finally we give some numerical results. AMS Classification subjects: 60G40 ; 93E20 ; 62P20 ; 91B99.

In this paper, I identify whether shifts within budgets occur and investigate the variation of these shifts. Building on stochastic process methods, I find that budgets in all four cases exhibit mostly incremental changes punctuated by extreme shifts. In order to explain these punctuations in budget distributions, I rely on two models: partisan control of government and partisan distance of the...