It has been widely demonstrated by many research works that the distribution of a factory can con... more It has been widely demonstrated by many research works that the distribution of a factory can condition its productivity. Because of this, a factory in Santiago, Chile, asked the authors for advice to evaluate the current situation in the company and what alternatives could be proposed to improve performance by increasing productivity without incurring too high costs. Among the most important requirements requested was a study of the current design of the raw materials warehouse within the plant since this is a main pillar in the design of the plant. For this purpose, the current layout ws analyzed and alternative designs were proposed under two scenarios: use the same area that is currently available or make the design from scratch considering land purchases to build the warehouse. In order to give a precise answer to many possible design decisions, formulations were developed and deduced to calculate the optimal dimensions of the warehouse, and qualitative criteria were incorporat...
This paper describes a strategy for defining priorities for the branching variables in a Branch a... more This paper describes a strategy for defining priorities for the branching variables in a Branch and Bound algorithm. The strategy is based on shape information about the polyhedron over which we are optimizing. This information is related to measures of the integer width, as provided by the so called ''Flatness Theorem''. Our selection rule uses that knowledge to define branching priorities on the variables. Computational results with simulated small to medium size integer problems are presented, as well with multi-knapsack problems. These show savings of about 40% in CPU time, as well as in nodes generated in the search tree, and compare favorably with respect to other standard branching rules.
It has been widely demonstrated by many research works that the distribution of a factory can con... more It has been widely demonstrated by many research works that the distribution of a factory can condition its productivity. Because of this, a factory in Santiago, Chile, asked the authors for advice to evaluate the current situation in the company and what alternatives could be proposed to improve performance by increasing productivity without incurring too high costs. Among the most important requirements requested was a study of the current design of the raw materials warehouse within the plant since this is a main pillar in the design of the plant. For this purpose, the current layout ws analyzed and alternative designs were proposed under two scenarios: use the same area that is currently available or make the design from scratch considering land purchases to build the warehouse. In order to give a precise answer to many possible design decisions, formulations were developed and deduced to calculate the optimal dimensions of the warehouse, and qualitative criteria were incorporat...
This paper describes a strategy for defining priorities for the branching variables in a Branch a... more This paper describes a strategy for defining priorities for the branching variables in a Branch and Bound algorithm. The strategy is based on shape information about the polyhedron over which we are optimizing. This information is related to measures of the integer width, as provided by the so called ''Flatness Theorem''. Our selection rule uses that knowledge to define branching priorities on the variables. Computational results with simulated small to medium size integer problems are presented, as well with multi-knapsack problems. These show savings of about 40% in CPU time, as well as in nodes generated in the search tree, and compare favorably with respect to other standard branching rules.
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Papers by Ivan Derpich