Sub-Population Genetic Algorithm with Mining Gene Structures for multiobjective FlowShop Scheduling Problems

[[abstract]]According to previous research of Chang et al. [Chang, P. C., Chen, S. H., & Lin, K. L. (2005b). Two phase sub-population genetic algorithm for parallel machine scheduling problem. Expert Systems with Applications, 29(3), 705–712], the sub-population genetic algorithm (SPGA) is effective in solving multiobjective scheduling problems. Based on the pioneer efforts, this research proposes a mining gene structure technique integrated with the SPGA. The mining problem of elite chromosomes is formulated as a linear assignment problem and a greedy heuristic using threshold to eliminate redundant information. As a result, artificial chromosomes are created according to this gene mining procedure and these artificial chromosomes will be reintroduced into the evolution process to improve the efficiency and solution quality of the procedure. In addition, to further increase the quality of the artificial chromosome, a dynamic threshold procedure is developed and the flowshop scheduling problems are applied as a benchmark problem for testing the developed algorithm. Extensive tests in the flow-shop scheduling problem show that the proposed approach can improve the performance of SPGA significantly.[[notice]]補正完

Using Heritage in Multi-Population Evolutionary Algorithms

Multi-Population Cultural Algorithms (MPCA) define a set of individuals that can be categorized as belonging to one of a set of populations. Not only reserved for Cultural Algorithms, the concept of Multi-Populations has been used in evolutionary algorithms to explore different search spaces or search for different goals simultaneously, with the capability of sharing knowledge with each other. The populations themselves can define specific goals or knowledge to use in the context of the problem. One limitation of MPCA is that an individual can only belong to one population at a time, which can restrict the potential and realism of the algorithm. This thesis proposes a novel approach to represent population usage called “Heritage,” which allows individuals to belong to multiple populations with weighted influence. Heritage-Dynamic Cultural Algorithm (HDCA) is used to test against different domains to examine the advantages and disadvantages of this approach

Application of Multidisciplinary Design Optimisation Frameworks for Engine Mapping and Calibration

With ever-increasing numbers of engine actuators to calibrate within increasingly stringent emissions legislation, the engine mapping and calibration task of identifying optimal actuator settings is much more difficult. The aim of this research is to evaluate the feasibility and effectiveness of the Multidisciplinary Design Optimisation (MDO) frameworks to optimise the multi-attribute steady state engine calibration optimisation problems. Accordingly, this research is concentrated on two aspects of the steady state engine calibration optimisation: 1) development of a sequential Design of Experiment (DoE) strategy to enhance the steady state engine mapping process, and 2) application of different MDO architectures to optimally calibrate the complex engine applications. The validation of this research is based on two case studies, the mapping and calibration optimisation of a JLR AJ133 Jaguar GDI engine; and calibration optimisation of an EU6 Jaguar passenger car diesel engine. These case studies illustrated that: -The proposed sequential DoE strategy offers a coherent framework for the engine mapping process including Screening, Model Building, and Model Validation sequences. Applying the DoE strategy for the GDI engine case study, the number of required engine test points was reduced by 30 – 50 %. - The MDO optimisation frameworks offer an effective approach for the steady state engine calibration, delivering a considerable fuel economy benefits. For instance, the MDO/ATC calibration solution reduced the fuel consumption over NEDC drive cycle for the GDI engine case study (i.e. with single injection strategy) by 7.11%, and for the diesel engine case study by 2.5%, compared to the benchmark solutions.UK Technology Strategy Board (TSB