Research On The Methods Of Bi-level Programming And Fuzzy Optimization For Steady-state Optimization Problem Of A Class Of Biochemical Systems

With the rapid development of science and technology, optimization engineering of biochemical systems has become increasingly important in today’s society. But biochemical process is a very complex non-linear process, so it is difficult to optimize and control. These need researchers to optimize biochemical process. This development of this technology optimization will help improving productivity of objective product. Furthermore, the whole production level of a biochemical process can be improved.For steady-state optimization problem of a class of biochemical systems, this paper presents a new method. The main research contents and results are as follow:1. It establishes a bi-level programming optimization model with second hierarchical structure for steady state optimization problem of a class of biochemical systems. The optimization goal of the upper and lower problem respectively maximizes a flux and minimizes the sum of metabolite concentrations of biochemical system. The biological significance of the model is as small as possible in the metabolic cost of conditions. The rate or concentration of product is maximum. In order to effectively solve the NP-hard, non convex bi-level programming problem, the application of equivalent transformation strategy in the framework of the S-system put forward a kind of optimization algorithm. This algorithm can solve optimization. The algorithm has advantages of simple operation and low competing cost. Numerical experiment results show that the new algorithm is feasible and effective. Compared with the results of existing single-layer planning method calculation, this bi-level programming method under the condition of minimal metabolic cost not only won the product of high yield, and greatly improved the metabolic cost of three important biological technologies. As a result, the optimization result is more practical significance.2. IOM(Indirect Optimization Method) method is a kind of classic algorithms. It applies linear programming to solve steady state optimization problem of biochemical systems. For linear programming in IOM method, the objective function coefficient, restraint coefficient, the resource of right of constraint conditions and parameters are fuzzy. In this paper, it consider the following three conditions.(1)The objective function is fuzzy.(2)The constraint right resources are fuzzy.(3)The whole coefficients are fuzzy. First, three fuzzy linear programming models are presented. Second, the effective optimization method is designed. Finally, the fuzzy optimization method is applied to two steady state optimization problems of biochemical systems.