Manning's roughness coefficient ( n ) is a comprehensive indicator of flow resistance, and significantly affects the accuracy of one-dimensional (1D) unsteady flow simulations. Most previous studies on roughness i...
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Manning's roughness coefficient ( n ) is a comprehensive indicator of flow resistance, and significantly affects the accuracy of one-dimensional (1D) unsteady flow simulations. Most previous studies on roughness inversion have focused on the variation of the n values along the reach & mdash;the variations of n with the discharge or water stage have seldom been investigated. To address this issue, an optimization model based on an adaptive parallel genetic algorithm (APGA) is proposed. This model enables better estimations of n in 1D unsteady flow simulations by considering the effects of both distance and discharge on n. The objective of the proposed model is to determine the optimal n values under different discharge strata for every sub-reach by minimizing the discrepancies between the simulated and measured water elevations and discharges. Moreover, a successive-approximation based stepwise optimizing (SABSO) strategy is developed to improve the performance of the APGA-based optimization model in long natural rivers. The proposed model is evaluated through a case study on the upper reaches of the Yangtze River, China, and compared with models where the n values are considered to vary with distance or discharge. The results show that the APGA with the SABSO strategy yields better solutions than the APGA alone, and that the proposed model outperforms models that do not consider variations of n with both discharge and distance. This research provides a novel approach for the inverse estimation of roughness in long river flows.
As an evaluation method, peer review is used in many business fields. The quality of experts appointed will affect the results of the final evaluation since experts' expertise will have a direct impact on evaluati...
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ISBN:
(纸本)9780769550794
As an evaluation method, peer review is used in many business fields. The quality of experts appointed will affect the results of the final evaluation since experts' expertise will have a direct impact on evaluation. This paper first analyzes the problem of expert assignment, then researches on its mathematical model and how to get the optimal Pareto, and finally discusses the feasibility of solving the problem of expert assignment through the application of geneticalgorithms. It mainly discusses how to solve APGA in the expert assignment process, and then gives out the process of APGA solution to the problem. The test proved that the APGA can effectively solve expert assignment problem. The same time, and random search algorithm and geneticalgorithm (SGA) to assign the results of APGA in the convergence speed and search ability has obvious advantages.
Access distributed power will take great influence to distribution network's safe and economic operation. This paper established a distribution network planning economic model and analyzed the advantages and disad...
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ISBN:
(纸本)9783037858615
Access distributed power will take great influence to distribution network's safe and economic operation. This paper established a distribution network planning economic model and analyzed the advantages and disadvantages of various planning algorithms, and propose an adaptive parallel genetic algorithm. This algorithm can overcome premature phenomenon of standard geneticalgorithm, and the ability is better to seek the global optimal solution.
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