BACKGROUND Responding to research confirming the link between nurse staffing and patient outcomes, 14 states have introduced legislation to limit patient-to-nurse ratios. However, increased staffing places a considerable financial burden on hospitals. OBJECTIVE We sought to determine the cost-effectiveness of various nurse staffing ratios. RESEARCH DESIGN This was a cost-effectiveness analy...

the air in tehran is one of the most polluted airs in the entire world. because of the air pollution in the great tehran area, morbidity, mortality and symptoms emerge. this study has been conducted for the first time in iran. according to this study the total annual direct medical costs of morbidity estimated at us$ 3258255.48.our work also led to the estimation of an income elasticity of wtp ...

this paper tries to determine efficiency of noise control method using fuzzy logic and based on collected data. from among various methods of noise control in workplace, sex methods (enclosure, installing noise absorber, enclosure and absorber, active, and administrative control, and personal protective equipment) were typically selected based on experts' judgment. for each of selected control ...

Modern energy demands led the scientific community to renewable energy sources, such as ocean wave energy. The present work describes a model for a cost efficient rotary electrical generator, optimized for ocean wave energy conversion. The electrical power, supplied by low speed mechanical movement, requires the use of electrical machinery capable of generating high amounts of torque. Among the...

this paper analyzes a controllable discrete-time machine repair problem withl operating machines and two repairmen. the number of working servers can be adjusteddepending on the number of failed machines in the system one at a time at machine's failure orat service completion epochs. analytical closed-form solutions of the stationary probabilities ofthe number of failed machines in the sys...