Recently Beltran-Royo et.al presented a Semi-Lagrangean relaxation for the classical p-median location problem. The results obtained using the Semi-Lagrangean relaxation approach were quite impressive. In this paper we use a reformulation of the p-median problem in order to start from a...

In this paper, we use a reformulation of the symmetric and the asymmetric travelling salesman problem more suitable for Lagrangean relaxation and analyse the new approach on examples from TSP Lib. Furthermore the Lagrangean relaxed subproblems are travelling salesman alike which means that...

Recently Beltrán-Royo, Vial & Alonso-Ayuso (2012) presented a semi-Lagrangean relaxation for the classical p-median location problem and for the incapacitated facility location problem. The results, obtained using the semi-Lagrangean relaxation approach, were quite impressive. In this paper we...

In this paper, we consider an operational routing problem to decide the daily routes of logging trucks in forestry. The industrial problem is difficult and includes aspects such as pickup and delivery with split pickups, multiple products, time windows, several time periods, multiple depots,...

In the given research we study a leadership formation of the most influential nodes in networks. Specifically, we analyze the competition between a leader and a follower based on the Stackelberg leadership model. Applying the concept of Shapley value to measure node’s importance, we represent...

We formulate the maintenance scheduling decision as a dynamic optimization problem, subject to an accelerating decay. This approach offers a formal, yet intuitive, weighting of the trade-offs involved when deciding a maintenance schedule. The optimal maintenance schedule reflects the trade-off...

Despite linear programming and duality have correctly been incorporated in algorithms to compute the nucleolus, we have found mistakes in how these have been used in a broad range of applications. Overlooking the fact that a linear program can have multiple optimal solutions and neglecting the...

In terms of social networks, split graphs correspond to the variety of interpersonal and intergroup relations. In this paper we analyse the interaction between the cliques (socially strong and trusty groups) and the independent sets (fragmented and non-connected groups of people) as the basic...

The storm Gudrun hit southern Sweden in January 2005 and approximately 70 million cubic meters of forest was wind felled. The existing logistic planning at forest companies in the damaged area had to be changed over night. There was a direct shortage of both harvest and transportation...

Motivated by the problems of the conventional model in rationalizing market data, we derive the equilibrium interest rate and risk premiums using recursive utility in continuous time. In a representative-agent framework our model allows for the separation of risk aversion from the time...