Recent adaptive memory and evolutionary metaheuristics for mixed integer programming have included proposals for introducing inequalities and target objectives to guide the search. These guidance approaches are useful in intensification and diversification strategies related to fixing subsets of variables at particular values, and in strategies that use linear programming to generate trial solu...

The lift-gas allocation problem with pressure-drop constraints and well-separator routing is a mixed-integer nonlinear program considerably hard to solve. To this end, a mixed-integer linear programming formulation was developed by multidimensional piecewiselinearization of pressure drop functions using standard (CC) and logarithmic (Log) aggregated models. These models were compared by means o...

A separation heuristic for mixed integer programs is presented that theoretically allows one to derive several families of “strong” valid inequalities for specific models and computationally gives results as good as or better than those obtained from several existing separation routines including flow cover and integer cover inequalities. The heuristic is based on aggregation of constraints of ...

in recent years, supply chain management has developed into one of the most critical strategies for achieving competitive advantage in different industries and the supplier selection process has increasingly been distinguished as an important and vital decision in supply chain management of manufacturing and service industries. on the other hand, with so many suppliers having different capabili...

A separation heuristic for mixed integer programs is presented that theoretically allows one to derive several families of \strong" valid inequalities for speciic models and computationally gives results as good as or better than those obtained from several existing separation routines including ow cover and integer cover inequalities. The heuristic is based on aggregation of constraints of the...

We introduce stochastic integer programs with dominance constraints induced by mixed-integer linear recourse. Closedness of the constraint set mapping with respect to perturbations of the underlying probability measure is derived. For discrete probability measures, large-scale, block-structured, mixed-integer linear programming equivalents to the dominance constrained stochastic programs are id...

the portfolio is a perfect combination of stock or assets, which an investor buys them. the objective of the portfolio is to divide the investment risk among several shares. using non-parametric dea and dea-r methods can be of great significance in estimating portfolio. in the present paper, the efficient portfolio is estimated by using non-radial dea and dea-r models. by proposing non-radial m...

Mixed integer programming is proposed as an approach for generating treatment plans for brachytherapy. Two related but distinct, mixed integer programming models are tested on data from eight prostate cancer patients. The results demonstrate that in some cases, "good" treatment plans can be obtained in less than five CPU minutes.

abstract: implementing a combined cooling, heating and power system(cchp) to cool, heat and produce electricity is growing rapidly due to its efficiency and low emissions. in this paper, using economic analysis, the size and operation detail of the required gas engine and the specific electricity, cooling and heating load curves for a one year operating period has been determined. the proposed ...

although several papers have studied no-idle scheduling problems, they all focus on flow shops, assuming one processor at each working stage. but, companies commonly extend to hybrid flow shops by duplicating machines in parallel in stages. this paper considers the problem of scheduling no-idle hybrid flow shops. a mixed integer linear programming model is first developed to mathematically form...