We give a generic regularity condition under which each weakly efficient decision making unit in the CCR model of data envelopment analysis is also CCR-efficient. Then we interpret the problem of finding maximal parameters which preserve efficiency of CCR-efficient DMUs under directional...

We consider the design of line plans in public transport at a minimal total cost. Both, linear and nonlinear integer programming are adequate and intuitive modeling approaches for this problem. We present a heuristic variable fixing procedure which builds on problem knowledge from both...

We develop mathematical tools suitable for the construction of conflict models with non-annihilating adversaries. In a set of probability measures we introduce a non-commutative conflict composition and consider the associated dynamical system. We prove that for each couple of non-identical...