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Indexed by:期刊论文

Date of Publication:2016-12-01

Journal:APPLIED MATHEMATICAL MODELLING

Included Journals:SCIE、EI、Scopus

Volume:40

Issue:23-24

Page Number:10533-10548

ISSN No.:0307-904X

Key Words:Switched time-delay system; Multi-objective optimization; Convex weighted sum; Normal boundary intersection; Fed-batch process

Abstract:Maximization of productivity and minimization of consumption are two top priorities for biotechnological industry. In this paper, we model a fed-batch process as a nonlinear switched time-delay system. Taking the productivity of target product and the consumption rate of substrate as the objective functions, we present a multi-objective optimization problem involving the nonlinear switched time-delay system and subject to continuous state inequality constraints. To solve the multi-objective optimization problem, we first convert the problem into a sequence of single-objective optimization problems by using convex weighted sum and normal boundary intersection methods. A gradient-based single-objective solver incorporating constraint transcription technique is then developed to solve these single-objective optimization problems. Finally, a numerical example is provided to verify the effectiveness of the numerical solution approach. Numerical results show that the normal boundary intersection method in conjunction with the developed single-objective solver is more favourable than the convex weighted sum method. (C) 2016 Elsevier Inc. All rights reserved.