Abstract Due to the phase-out of CFCs and HCFC refrigerants, propane is a nature refrigerant occurring substance produced by natural gas production oil refining. As result, has higher latent heat lower density than conventional refrigerants while maintaining comparable saturation pressure thermal conductivity. So, already widely used in domestic fridges freezers for many years. However, propane...

in this paper the issue of evaluating iranian oil refineries performance has been discussed. the research is based on math modelling by operational research techniques. to do so, of the proposed scenarios and different math programming models, a model is made by combining dea with goal programming techniques that compared with the old classical dea models which measures the efficiency and produ...

Our purpose is to formalize two potential refinements of single-sorted algebraic data types – subalgebras and algebras which satisfy equivalence relations – by considering their categorical interpretation. We review the usual categorical formalization of singleand multi-sorted algebraic data types as initial algebras, and the correspondence between algebraic data types and endofunctors. We intr...

Inspired by Cardelli’s pioneering work, many type disciplines for object-oriented programming are based on enrichments of structural type theories with constructs such as subtyping and bounded polymorphism. A principal benefit of such a formulation is that the absence of “message not understood” errors is an immediate corollary of the type safety theorem. A principal drawback is that the result...

In this paper we present a calculus for re nement of business process models based on a precise de nition of business processes and process nets Business process models are a vital concept for communicating with experts of the application domain Depending on the roles and responsibilities of the application domain experts involved process models are discussed on di erent levels of ab straction ...