Normal-Boundary Intersection (NBI), a new technique for solving nonlinear multicriteria optimization problems, is now available online. Developed by CRPC Optimization Group leader John Dennis and graduate student Indraneel Das of Rice University, the NBI package can be downloaded for free from the NBI home page at

NBI can be used to solve a wide variety of engineering design optimization problems that are multicriteria in nature. For example, a typical bridge construction design might involve simultaneously minimizing the total mass of the structure and maximizing its stiffness. There must be some tradeoff between the objective functions to ensure an efficient design. NBI will find optimal points for a general optimization problem while capturing the tradeoff among various conflicting objectives.

NBI has several advantages over existing methods for multicriteria optimization. For example, for a bi-objective optimization problem, NBI parametrization of the efficient frontier naturally bears the property of even spread, unlike most traditional techniques. Moreover, this method can be extended to the case of more than two objectives, unlike homotopy techniques which can handle only bi-objective problems.

For more information, see the technical report, "Normal-Bound Intersection: An Alternate Method for Generating Pareto Optimal Points in Multicriteria Optimization Problems," available from the NBI home page.

Other Issues of PCR Back to PCR CRPC Home Page