In this paper, we consider the problem of partner selection in a virtual organisation (VO); specifically, we develop mixed integer linear programming (MILP) models to support the configuration of VOs in a virtual organisation breeding environment (VBE). Apart from the basic model which focuses on the minimisation of total fixed and variable costs we present extensions that capture transportatio...

We consider the following Minimum Connectivity Inference problem (MCI), which arises in structural biology: given vertex sets Vi ⊆ V, i ∈ I, nd the graph G = (V,E) minimizing the size of the edge set E, such that the sub-graph of G induced by each Vi is connected. This problem arises in structural biology, when one aims at nding the pairwise contacts between the proteins of a protein assembly, ...

The Dependency Diagram of a Linear Programme (LP) shows how the successive inequalities of an LP depend on former inequalities, when variables are projected out by FourierMotzkin Elimination. This is explained in a paper referenced below. The paper, given here, extends the results to the Mixed Integer case (MILP). It is shown how projection of a MILP leads to a …nite disjunction of polytopes. T...

We present a method, based on formulation symmetry, for generating Mixed-Integer Linear Programming (MILP) relaxations with fewer variables than the original symmetric MILP. Our technique also extends to convex MINLP, and some nonconvex MINLP with a special structure. We showcase the effectiveness of our relaxation when embedded in a decomposition method applied to two important applications (m...

This paper addresses the problem of developing an optimisation model to aid the operational decision-making process in pipeline systems. The model is applied on a real world pipeline oil distribution scenario, which connects an inland refinery to a harbour, conveying multiple types of commodities. The optimisation model was developed based on mixed integer linear programming (MILP) with uniform...

In this paper, we present a mixed-integer linear program (MILP) designed to optimize max-min path lifetime for multicasts in directional antenna equipped networks in the presence of interference. We then employ the MILP to perform a head-to-head comparison between directional transmission and directional reception. We also propose and analyze a new directional reception heuristic. Our results i...

A new model has been developed for multicommodity transportation and supply chain problems including stepwise constant costs. The model is expressed as an MILP problem. The modelling equations are presented here. The new model has been tested on multicommodity problem of SABMiller Europe, and compared to other methods from the literature. A feasibility checking method has been developed for lar...

This paper considers the multi level uncapacitated facility location problem (MLUFLP). A new mixed integer linear programming (MILP) formulation is presented and validity of this formulation is given. Experimental results are performed on instances known from literature. The results achieved by CPLEX and Gurobi solvers, based on the proposed MILP formulation, are compared to the results obtaine...