We revise the classic methodology to find the multi-product break-even point. In the current paper we propose a solution to the problem under uncertainty conditions, based on Durán Herrera’s crisp approach [3] and applying fuzzy linear programming. We introduce the concept of approximate break-even for cases in which, due to the nature of the problem, it is not possible to find the break-even p...

due to the increasing cost and environmental impacts of fossil fuel consumption, using the renewable energies in data center has become an important and essential priority. although using renewable energies has less environmental harmful effects, but the high investment needed for their installations as well as their fluctuating power production characteristic, restricts their usage such that m...

The propagator for the massless vector field in de Sitter space cannot maintain invariance general covaraint gauge, except exactly transverse gauge limit. This is due to a previously overlooked Ward-Takahashi identity that must satisfy. Here we construct satisfies all conditions of consistently quantized theory. Our solution preserves cosmological symmetries and dilations, but breaks spatial sp...