Browsing by Author "Yeh, Chao-Hsien"

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Multiobjective planning of surface water resources by multiobjective genetic algorithm with constrained differential dynamic programming
(2007-11-01)
Yang, Chao-Chung
;
Chang, Liang-Cheng
;
Yeh, Chao-Hsien
;
Chen, Chang-Shian
;
土木工程學系
Owing to the conflict encountered between the two objectives of fixed cost in reservoir installation and operating cost in time-varying water deficit, multiobjective planning of surface water resources is a difficult job. Instead of combining these two objectives into just one objective using the weighting factor approach, this investigation proposes a novel method by integrating a multiobjective genetic algorithm (MOGA) with constrained differential dynamic programming (CDDP). A MOGA is employed to generate the various combinations of reservoir capacity and estimate the noninferior solution set. However, applying this algorithm to solve the dynamics of the operating cost, the number of variables increasing with time will dramatically increase the use of computational resources. Consequently, the CDDP is herein adopted to distribute optimal releases among reservoirs to satisfy water demand as much as possible. Next, the effectiveness of the proposed methodology is verified by solving a multiobjective planning problem of surface water in southern Taiwan. This real application demonstrates that MOGA can be linked with CDDP to resolve a complex water resources problem. Additionally, the ability of MOGA on addressing multiple objectives simultaneously without converting to a weighted objective function provides the opportunity for significant advancement in multiobjective optimization. Finally, this investigation also proposes three suitable strategies of reservoir construction to decision makers With budget concerns through the analysis of all noninferior solutions.
The application of system dynamics to water resources sustainable use for the Kaopin river basin
(2005)
Yang, Chao-Chung
;
Shan, Hsin-Yu
;
Lee, Han-Keng
;
Hsu, Shao-hua
;
Chen, Tze-Wei
The demand for water in Kaopin river basin has increased significantly in recent years owing to industrial growth and increasing living standards. This situation not only raises the crisis of water deficit but also brings serious problem of water pollution. Hence, any suitable strategy is required to consider simultaneously the effect between water quantity and water quality. A system dynamics model is including the critical feedback structures in the system. Simulating the model shows the effect of the system structure on policy interventions. Therefore, system dynamics is well-suited to analyzing problems whose behavior is governed by feedback relationships and which have a long-term time horizon. Finally, this study addressed two major problems: 1) water deficit, 2) water pollution and then makes the appropriate strategy to avoid the huge impact between water deficit and water pollution and also prohibit the time delay of strategy.