Through analysis the actual coal supply and demand in the US and China, the properties of the coal supply-demand market in both countries are investigated based on the energy supply-demand network. The validity of our...Through analysis the actual coal supply and demand in the US and China, the properties of the coal supply-demand market in both countries are investigated based on the energy supply-demand network. The validity of our model is verified by comparing numerical results with empirical results. The comparison of empirical results and the comparison of coal network model parameters between in the US and in China reveal the essence of the internal differences and similarities of coal supply and demand in these two countries. The third stage of China＇s coal network was close to that of the US in 1995, indicating that the evolutional situation of China＇s coal market begins to transit to an oligopolistic type. Finally, suggestions for China＇s coal supply-demand strategy are put forward.展开更多
Water scarcity is currently still a global challenge despite the fact that water sustains life on earth. An understanding of domestic water demand is therefore vital for effective water management. In order to underst...Water scarcity is currently still a global challenge despite the fact that water sustains life on earth. An understanding of domestic water demand is therefore vital for effective water management. In order to understand and predict future water demand, appropriate mathematical models are needed. The present work used Geographic Information Systems (GIS) based regression models;Geographically weighted regression (GWR) and Ordinary Least Square (OLS) to model domestic water demand in Athi river town. We identified a total of 7 water determinant factors in our study area. From these factors, 4 most significant ones (household size, household income, meter connections and household rooms) were identified using OLS. Further, GWR technique was used to investigate any intrinsic relationship between the factors and water demand occurrence. GWR coefficients values computed were mapped to exhibit the relationship and strength of each explanatory variable to water demand. By comparing OLS and GWR models with both AIC value and R2 value, the results demonstrated GWR model as capable of projecting water demand compared to OLS model. The GWR model was therefore adopted to predict water demand in the year 2022. It revealed domestic water demand in 2017 was estimated at 721,899 m3 compared to 880,769 m3 in 2022, explaining an increase of about 22%. Generally, the results of this study can be used by water resource planners and managers to effectively manage existing water resources and as baseline information for planning a cost-effective and reliable water supply sources to the residents of a town.展开更多
随着新型电力系统的建设,虚拟电厂(Virtual Power Plant,VPP)在整合分布式能源、可控负荷以及储能资源方面发挥着重要作用。评估虚拟电厂中不同用户的需求响应潜力对于优化电网调度、提升电网运行效率具有重要意义。本文提出了一种基于...随着新型电力系统的建设,虚拟电厂(Virtual Power Plant,VPP)在整合分布式能源、可控负荷以及储能资源方面发挥着重要作用。评估虚拟电厂中不同用户的需求响应潜力对于优化电网调度、提升电网运行效率具有重要意义。本文提出了一种基于负荷时间弹性和价格弹性相结合的需求响应潜力评估方法,并结合熵权法确定各指标的权重,旨在实现对用户需求响应能力的全面量化评估。通过对浙江金华地区典型电力用户的实证分析,本文验证了所提出方法的有效性和实用性。研究结果表明,负荷时间弹性在评估中起到了关键作用,而价格弹性影响相对较小。此外,本文的方法能够通过数据驱动的聚类分析,识别不同用户的负荷特性,从而为虚拟电厂的优化调度提供依据。本文的研究为新型电力系统下虚拟电厂的需求响应管理提供了理论支持,并为未来研究指出了进一步改进的方向。展开更多
为了更合理高效地在灾害发生时对不同受灾点进行应急救援,提出了一种基于组合赋权的优劣解距离法(technique for order preference by similarity to an ideal solution,TOPSIS)模型,对受灾点救援需求紧迫度进行分级研究。首先,分析受...为了更合理高效地在灾害发生时对不同受灾点进行应急救援,提出了一种基于组合赋权的优劣解距离法(technique for order preference by similarity to an ideal solution,TOPSIS)模型,对受灾点救援需求紧迫度进行分级研究。首先,分析受灾点救援需求紧迫度的影响因素,构建受灾点救援需求紧迫度评价指标体系;其次,综合运用客观权重赋值法(criteria importance though intercrieria correlation,CRITIC)和熵权法对各指标进行组合赋权;然后,运用组合赋权-TOPSIS法对受灾点救援需求紧迫度量化分级;最后,以汶川地震为背景进行算例分析,结果表明:组合赋权所得权值相比单一赋权能够得到更加客观合理的结果,有利于灾害发生情况下应急管理部门更加及时、准确、有序地进行应急救援。展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos.71073071 and 71273119)the Major Program of Social Science Foundation of Jiangsu Education Office,China (Grant No.2010-2-10)
文摘Through analysis the actual coal supply and demand in the US and China, the properties of the coal supply-demand market in both countries are investigated based on the energy supply-demand network. The validity of our model is verified by comparing numerical results with empirical results. The comparison of empirical results and the comparison of coal network model parameters between in the US and in China reveal the essence of the internal differences and similarities of coal supply and demand in these two countries. The third stage of China＇s coal network was close to that of the US in 1995, indicating that the evolutional situation of China＇s coal market begins to transit to an oligopolistic type. Finally, suggestions for China＇s coal supply-demand strategy are put forward.
文摘Water scarcity is currently still a global challenge despite the fact that water sustains life on earth. An understanding of domestic water demand is therefore vital for effective water management. In order to understand and predict future water demand, appropriate mathematical models are needed. The present work used Geographic Information Systems (GIS) based regression models;Geographically weighted regression (GWR) and Ordinary Least Square (OLS) to model domestic water demand in Athi river town. We identified a total of 7 water determinant factors in our study area. From these factors, 4 most significant ones (household size, household income, meter connections and household rooms) were identified using OLS. Further, GWR technique was used to investigate any intrinsic relationship between the factors and water demand occurrence. GWR coefficients values computed were mapped to exhibit the relationship and strength of each explanatory variable to water demand. By comparing OLS and GWR models with both AIC value and R2 value, the results demonstrated GWR model as capable of projecting water demand compared to OLS model. The GWR model was therefore adopted to predict water demand in the year 2022. It revealed domestic water demand in 2017 was estimated at 721,899 m3 compared to 880,769 m3 in 2022, explaining an increase of about 22%. Generally, the results of this study can be used by water resource planners and managers to effectively manage existing water resources and as baseline information for planning a cost-effective and reliable water supply sources to the residents of a town.
文摘随着新型电力系统的建设,虚拟电厂(Virtual Power Plant,VPP)在整合分布式能源、可控负荷以及储能资源方面发挥着重要作用。评估虚拟电厂中不同用户的需求响应潜力对于优化电网调度、提升电网运行效率具有重要意义。本文提出了一种基于负荷时间弹性和价格弹性相结合的需求响应潜力评估方法,并结合熵权法确定各指标的权重,旨在实现对用户需求响应能力的全面量化评估。通过对浙江金华地区典型电力用户的实证分析,本文验证了所提出方法的有效性和实用性。研究结果表明,负荷时间弹性在评估中起到了关键作用,而价格弹性影响相对较小。此外,本文的方法能够通过数据驱动的聚类分析,识别不同用户的负荷特性,从而为虚拟电厂的优化调度提供依据。本文的研究为新型电力系统下虚拟电厂的需求响应管理提供了理论支持,并为未来研究指出了进一步改进的方向。
文摘为了更合理高效地在灾害发生时对不同受灾点进行应急救援,提出了一种基于组合赋权的优劣解距离法(technique for order preference by similarity to an ideal solution,TOPSIS)模型,对受灾点救援需求紧迫度进行分级研究。首先,分析受灾点救援需求紧迫度的影响因素,构建受灾点救援需求紧迫度评价指标体系;其次,综合运用客观权重赋值法(criteria importance though intercrieria correlation,CRITIC)和熵权法对各指标进行组合赋权;然后,运用组合赋权-TOPSIS法对受灾点救援需求紧迫度量化分级;最后,以汶川地震为背景进行算例分析,结果表明:组合赋权所得权值相比单一赋权能够得到更加客观合理的结果,有利于灾害发生情况下应急管理部门更加及时、准确、有序地进行应急救援。
