Competing Design Objectives Research Articles

Application of Genetic Algorithms for the Design of Ozone Control Strategies

ABSTRACT Designing air quality management strategies is complicated by the difficulty in simultaneously considering large amounts of relevant data, sophisticated air quality models, competing design objectives, and unquantifiable issues. For many problems, mathematical optimization can be used to simplify the design process by identifying cost-effective solutions. Optimization applications for controlling nonlinearly reactive pollutants such as tropospheric ozone, however, have been lacking because of the difficulty in representing nonlinear chemistry in mathematical programming models. We discuss the use of genetic algorithms (GAs) as an alternative optimization approach for developing ozone control strategies. A GA formulation is described and demonstrated for an urban-scale ozone control problem in which controls are considered for thousands of pollutant sources simultaneously. A simple air quality model is integrated into the GA to represent ozone transport and chemistry. Variations of the GA formulation for multiobjective and chance-constrained optimization are also presented. The paper concludes with a discussion of the practicality of using more sophisticated, regulatory-scale air quality models with the GA. We anticipate that such an approach will be practical in the near term for supporting regulatory decision-making.

Optimization Based Design and Control

The use of optimization for the design of control systems with many, competing design objectives, is explored.A canonical form for the design problem is presented, and it is shown how a variety of design objectives may be transcribed into this form. Methods for solving the resulting mathematical programming problem are presented. The effective handling of control and state constraints requires a nonlinear controller. Receding horizon, or model predictive (optimization based) control is an effective method of achieving nonlinearcontrol of constrained systems when the plant is sufficiently slow to permit, online, approximate solution of openloop optimal control problems. Recent research that enhances the applicability of this type of control to constrained nonlinear systems is described.

Closure to “Discussions of ‘The Optimum Design of Mechanical Systems With Competing Design Objectives’” (1974, ASME J. Eng. Ind., 96, pp. 1103–1104)

Closure to “Discussions of ‘The Optimum Design of Mechanical Systems With Competing Design Objectives’” (1974, ASME J. Eng. Ind., 96, pp. 1103–1104)

The Optimum Design of Mechanical Systems With Competing Design Objectives

A general method is developed for analyzing optimum design problems with multiple, competing objective junctions. Methods are presented for generating trade-off curves for problems with competing objectives. The usefulness of these methods is demonstrated by applying them to the optimum design of hydrodynamic journal bearings.