this paper addresses the mixed integer reliability redundancy allocation problems to determine simultaneous allocation of optimal reliability and redundancy level of components based on three objective goals. system engineering principles suggest that the best design is the design that maximizes the system operational effectiveness and at the same time minimizes the total cost of ownership (tco...

The population of Easter Island grew steadily for some time and then suddenly decreased dramatically; humans almost disappeared from the island. This is not the sort of behavior predicted by the usual logistic differential equation model of an isolated population or by the predator-prey model for a population using resources. We present a mathematical model that predicts this type of behavior w...

We study an elections model in which political parties are internally divided between an “elite” and a “base” whose preferences are imperfectly aligned. Elites are better informed about the quality of potential nominees, and their endorsements can identify and promote high quality candidates. However, elites may also choose to restrict their endorsements to candidates who adopt their preferred ...

Systems of computers and their application in the lives of modern human beings are vastly expanding. In any kind of computer application, failure in computer systems can lead to a range of financial and mortal losses. Indeed, the major origin of software failure can be located in designing or implementing software. With regard to these statistics, 30% of the software projects have been prospero...

  The importance of reliable supply is increasing with supply chain network extension and just-in-time (JIT) production. Just in time implications motivate manufacturers towards single sourcing, which often involves problems with unreliable suppliers. If a single and reliable vendor is not available, manufacturer can split the order among the vendors in order to simultaneously decrease the supp...

OBJECTIVES To assess the association between medical marijuana laws (MMLs) and the odds of a positive opioid test, an indicator for prior use. METHODS We analyzed 1999-2013 Fatality Analysis Reporting System (FARS) data from 18 states that tested for alcohol and other drugs in at least 80% of drivers who died within 1 hour of crashing (n = 68 394). Within-state and between-state comparisons a...

We study single and multistage inventory systems with stochastic lead times. We study a class of stochastic lead time processes, which we refer to as exogenous lead times. This class of lead time processes includes as special cases all lead time models from existing literature (such as Kaplan’s lead times with no order crossing or independent and identically distributed lead times with order cr...

This is the second of two closely related systematic literature reviews with meta-analyses by same authors. The first concluded that there no convincing epidemiological evidence prior use cannabis (as indicated presence THC in a body fluid) directly increases risk crashing. purpose this review to consider possibility co-use indirectly crashing exacerbating effect alcohol on starting point for b...