This study uses a Cox proportional hazards model to analyze changes in the risk of unplanned outages in U.S. nuclear power plants after the Three Mile Island (TMI) accident. The unplanned outage hazard is related to safety by the fact that most such outages begin with unplanned reactor scrams....

We present an original modeling tool that can be used to study the social mechanisms by which individual software developers’ efforts are allocated within large and complex open source projects. The dynamical agent-based model is first described analytically in a deterministic discrete choice...