Cost minimization of a multiple section power cable supplying several remote telecom equipment

Abstract An optimization problem is described, that arises in telecommunications and is associated with multiple cross-sections of a single power cable used to supply remote telecom equipments. The problem consists of minimizing the volume of copper material used in the cables and consequently the total cable cost. Two main formulations for the problem are introduced and some properties of the functions and constraints involved are presented. In particular it is shown that the optimization problems are convex and have a unique optimal solution. A Projected Gradient algorithm is proposed for finding the global minimum of the optimization problem, taking advantage of the particular structure of the second formulation. An analysis of the performance of the algorithm for given real-life problems is also presented

How to make industrial symbiosis profitable

Industrial symbiosis can well represent a new kind of collaborative network which demands resolute attention to the flow management of materials, by-products, and waste through local and regional economies. Industrial symbiosis engages traditionally separate companies in a collaborative approach to competitive advantage involving physical exchange of different kind of products which are usually disregard by traditional market transitions. The identification of innovative models to support decision-making process in this kind of networks is urgent since it is necessary to close the loop assuring profitability at a single node as well as at system level. This paper proposes the application of the bi-level optimization model as a way to handle this two-stage problem organized into two cooperating layers. As a preliminary result, the model is applied to a simplified case where the nodes can sell their output to the market or share them in the industrial symbiosis to increase the global efficiency