the impact of the international sanctions on the central bank of iran in 2013 and also accessibility of medicines in this country have received a lot of media coverage. in this study we used the data collected from a group of pharmacies all located in tehran to assess the potential effects of the banking sanctions on access to asthma medicines. data were collected from forty community pharmacie...

Situationand resource-aware security is essential for the process control systems, composed of networked entities with sensors and actuators, that monitor and control the national critical infrastructure. However, security cannot be addressed at a single layer because of the inherent dependencies and tradeoffs among crosscutting concerns. Techniques applied at one layer to improve security affe...

Ensuring the availability of enterprise IT systems is a challenging task. The factors that can bring systems down are numerous, and their impact on various system architectures is difficult to predict. At the same time, maintaining high availability is crucial in many applications, ranging from control systems in the electric power grid, over electronic trading systems on the stock market to sp...

In the present investigation, we deal with the reliability characteristics of a repairable system consisting of two independent operating units, by incorporating the coverage factor. The probability of the successful detection, location and recovery from a failure is known as the coverage probability. The reboot delay and common cause shock failure are also considered. The times to failure of t...

Bi-objective optimization of the availability allocation problem in a series–parallel system with repairable components is aimed in this paper. The two objectives of the problem are the availability of the system and the total cost of the system. Regarding the previous studies in series–parallel systems, the main contribution of this study is to expand the redundancy allocation problems to syst...

in this study, to determine the economic value of irrigation water and simulate the response of farmers to reducing  available water policy of positive mathematical programming models (pmp) was used. by the proposed model, the economic value (shadow price) of irrigation water estimated in each of the areas of western rodbar alamuot, rajai dasht and eastern rodbar almuot. then, the reactions of ...

When a component fails in a critical communications service, how urgent is a repair? If we repair within 1 hour, 2 hours, or n hours, how does this affect the likelihood of service failure? Can a formal model support assessing the impact, prioritisation, and scheduling of repairs in the event of component failures, and forecasting of maintenance costs? These are some of the questions posed to u...

In this paper we study the steady state availability of main k-out-of-n: F and secondary subsystems having general repair time distribution. When more than k units of main subsystem fail, then the main subsystem shuts off the secondary subsystem. The life time distributions of the main units and that of secondary subsystem are exponentially distributed. A repair facility having single repairman...