排序方式: 共有43条查询结果,搜索用时 15 毫秒
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Chu Shipeng Zhang Tuqiao Zhou Xinhong Yu Tingchao Shao Yu 《Water Resources Management》2022,36(2):491-505
Water Resources Management - Real-time modeling of a water distribution system (WDS) is a critical step for the control and operation of such systems. The nodal water demand, as the most important... 相似文献
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沥青是一种成分比较复杂的无定型高分子化合物的混合物,同时沥青路面又是工作在复杂多变的气候条件与交通荷载的情况下,如何将各种情况下沥青路面的使用品质同沥青及沥青混合料的性能指标联系起来需要大量的工作。本文主要通过车辙试验和小梁低温弯曲破坏试验研究沥青混合料的高温稳定性能和低温抗裂性能。结果表明:普通沥青的稠度和改性沥青回归后的粘度与动稳定度有比较好的相关性,且相关性优于传统高温指标,稠度在反映沥青高温性能方面具有重要的意义;由于混合料的复杂性,使沥青指标与混合料的的相关性有所下降,但仍表现出好于传统指标的优越性,测力延度在反映沥青抗裂能力方面具有更大的应用价值。 相似文献
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Feifei Zheng Zhexian Qi Weiwei Bi Tuqiao Zhang Tingchao Yu Yu Shao 《Water Resources Management》2017,31(4):1121-1138
In recent years, multi-objective evolutionary algorithms (MOEAs) have been widely used to handle various water resources problems. One challenge within MOEAs’ applications is a lack of understanding on how various operators alter a MOEA’s behavior to achieve its final performance (i.e., MOEAs are black-boxes to practitioners), and hence it is difficult to select the most appropriate operators to ensure the MOEA’s best performance for a given real-world problem. To address this issue, this study proposes the use of the run-time measure metrics to reveal the underlying searching behavior of the MOEA’s operators. The proposed methodology is demonstrated by the non-dominated sorting genetic algorithm II (NSGA-II, a widely used MOEA in water resources) with five commonly used crossover operators applied to six water distribution system design problems. Results show that the simulated binary crossover (SBX) and the simplex crossover (SPX) operators possess great ability in extending the front and finding Pareto-front solutions, respectively, while the naive crossover (NVX) strategy exhibits the overall worst performance in identifying optimal fronts. The obtained understanding on the operators’ searching behavior not only offers guidance for selecting appropriate operators for real-world water resources problems, but also builds fundamental knowledge for developing more advanced MOEAs in future. 相似文献
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针对供水管网中余氯及氯仿(THM)服务水平优化问题,提出了一种衡量THM服务水平的表达式,推导了THM-I/O模型,建立了以管网余氯服务水平最大化、THM服务水平最大化以及加氯费用最小化的多目标优化模型。考虑了主体水余氯衰减系数、基于余氯消耗的THM生成比例系数、出厂水THM浓度、加氯点数量4个影响因素对优化结果Pareto前沿面的影响。结合一管网算例,采用EPANET_MSX模拟余氯衰减和THM生成,利用实数编码的非支配排序遗传算法Ⅱ(NSGA-Ⅱ)进行优化,可得到各种情况下的Pareto前沿面。计算结果表明,随着主体水余氯衰减系数减小,加氯费用减少,THM服务水平增加。基于余氯消耗的THM生成比例系数和出厂水THM浓度的减小均能提高THM服务水平,但对加氯费用没有影响。增加加氯点虽然能减少余氯投加,但加氯站建设费用加大了总加氯费用。降低主体水余氯衰减系数是提高管网水质服务水平最经济有效的方法。 相似文献
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