abstract: in this paper, an exergy analysis approach is proposed for optimal design of distillation column by using simulated annealing algorithm. first, the simulation of a distillation column was performed by using the shortcut results and irreversibility in each tray was obtained. the area beneath the exergy loss profile was used as irreversibility index in the whole column. then, first opti...

State-of-the-art database design tools rely on the query optimizer for comparing between physical design alternatives. Although it provides an appropriate cost model for physical design, query optimization is a computationally expensive process. The significant time consumed by optimizer invocations poses serious performance limitations for physical design tools, causing long running times, esp...

State-of-the-art database design tools rely on the query optimizer for comparing between physical design alternatives. Although it provides an appropriate cost model for physical design, query optimization is a computationally expensive process. The significant time consumed by optimizer invocations poses serious performance limitations for physical design tools, causing long running times, esp...

In some data envelopment analysis (DEA) applications, some inputs of DMUs have negative values with positive cost. This paper generalizes the global cost Malmquist productivity index to compare the productivity of dierent DMUs with negative inputs in any two periods of times under variable returns to scale (VRS) technology, and then the generalized index is decomposed to several components. The...