Load flow studies play a critical role in the analysis of power systems. They enable the computation of voltage, current, and power flows in a power system. They provide valuable insights into the steady-state perform...Load flow studies play a critical role in the analysis of power systems. They enable the computation of voltage, current, and power flows in a power system. They provide valuable insights into the steady-state performance of the power system under different operating conditions. Choosing a slack bus is a vital step in conducting load flow simulations. A slack bus is a PV bus that includes a generator and is used to balance real and reactive power during load flow studies. Many studies have been conducted on the selection of slack buses in load flow analysis. However, varied conclusions regarding the impact on system losses and power flows were obtained during these studies. Therefore, using the IEEE-14 bus test system, this study investigated the effects of slack bus selection in strong and weak grids by alternating slack buses among PV buses and observing the effects on bus voltage magnitude, bus voltage phase angle, total power flows, and active and reactive power losses. The study noted that the effect of slack bus selection on these system quantities is contingent upon the voltage stability of the grid. Whereas in a robust grid, system losses and power flows remained constant irrespective of the choice of slack bus, a weak grid experienced some variations in these system quantities under similar circumstances. The simulation results led to the conclusion that, to a large extent, the voltage stability of the grid plays a significant role in determining the degree to which slack bus selection affects system losses and other quantities in load flow studies.展开更多
本文利用卫星监测的数据构造夜间灯光复合指数表征城镇化水平,运用Superefficiency Ray Slacks-Based Measure(Super-RSBM)模型和Global Malmquist-Luenberger(GML)指数测算2000—2021年我国农业低碳全要素生产率(TFP),实证检验城镇化...本文利用卫星监测的数据构造夜间灯光复合指数表征城镇化水平,运用Superefficiency Ray Slacks-Based Measure(Super-RSBM)模型和Global Malmquist-Luenberger(GML)指数测算2000—2021年我国农业低碳全要素生产率(TFP),实证检验城镇化对我国农业低碳TFP的影响及其作用机制,并考察紧凑集约型和规模扩张型两种城镇化推进模式对农业低碳TFP的异质性影响。研究发现,从全国来看,城镇化推进与农业低碳TFP之间具有显著的U型关系,且邻近地区农业低碳TFP的提升对本地区产生示范效应;分区域来看,这种U型关系主要体现在农业适度发展区,而农业优化发展区的城镇化与农业低碳TFP之间呈现显著的正向线性关系,表明农业优化发展区应发挥“领头羊”作用,带动适度发展区早日跨越U型曲线的拐点,实现城镇化带动农业绿色发展;紧凑集约型的城镇化深度推进模式能够显著提升农业低碳TFP,而规模扩张型的城镇化广度推进模式降低了农业低碳TFP;农业低碳技术进步、农村劳动力转移、规模效应、农业产业链延伸和农村居民可支配收入增加是城镇化影响农业低碳TFP的主要途径。展开更多
In the context of enterprise systems,intrusion detection(ID)emerges as a critical element driving the digital transformation of enterprises.With systems spanning various sectors of enterprises geographically dispersed...In the context of enterprise systems,intrusion detection(ID)emerges as a critical element driving the digital transformation of enterprises.With systems spanning various sectors of enterprises geographically dispersed,the necessity for seamless information exchange has surged significantly.The existing cross-domain solutions are challenged by such issues as insufficient security,high communication overhead,and a lack of effective update mechanisms,rendering them less feasible for prolonged application on resource-limited devices.This study proposes a new cross-domain collaboration scheme based on federated chains to streamline the server-side workload.Within this framework,individual nodes solely engage in training local data and subsequently amalgamate the final model employing a federated learning algorithm to uphold enterprise systems with efficiency and security.To curtail the resource utilization of blockchains and deter malicious nodes,a node administration module predicated on the workload paradigm is introduced,enabling the release of surplus resources in response to variations in a node’s contribution metric.Upon encountering an intrusion,the system triggers an alert and logs the characteristics of the breach,facilitating a comprehensive global update across all nodes for collective defense.Experimental results across multiple scenarios have verified the security and effectiveness of the proposed solution,with no loss of its recognition accuracy.展开更多
文摘Load flow studies play a critical role in the analysis of power systems. They enable the computation of voltage, current, and power flows in a power system. They provide valuable insights into the steady-state performance of the power system under different operating conditions. Choosing a slack bus is a vital step in conducting load flow simulations. A slack bus is a PV bus that includes a generator and is used to balance real and reactive power during load flow studies. Many studies have been conducted on the selection of slack buses in load flow analysis. However, varied conclusions regarding the impact on system losses and power flows were obtained during these studies. Therefore, using the IEEE-14 bus test system, this study investigated the effects of slack bus selection in strong and weak grids by alternating slack buses among PV buses and observing the effects on bus voltage magnitude, bus voltage phase angle, total power flows, and active and reactive power losses. The study noted that the effect of slack bus selection on these system quantities is contingent upon the voltage stability of the grid. Whereas in a robust grid, system losses and power flows remained constant irrespective of the choice of slack bus, a weak grid experienced some variations in these system quantities under similar circumstances. The simulation results led to the conclusion that, to a large extent, the voltage stability of the grid plays a significant role in determining the degree to which slack bus selection affects system losses and other quantities in load flow studies.
文摘本文利用卫星监测的数据构造夜间灯光复合指数表征城镇化水平,运用Superefficiency Ray Slacks-Based Measure(Super-RSBM)模型和Global Malmquist-Luenberger(GML)指数测算2000—2021年我国农业低碳全要素生产率(TFP),实证检验城镇化对我国农业低碳TFP的影响及其作用机制,并考察紧凑集约型和规模扩张型两种城镇化推进模式对农业低碳TFP的异质性影响。研究发现,从全国来看,城镇化推进与农业低碳TFP之间具有显著的U型关系,且邻近地区农业低碳TFP的提升对本地区产生示范效应;分区域来看,这种U型关系主要体现在农业适度发展区,而农业优化发展区的城镇化与农业低碳TFP之间呈现显著的正向线性关系,表明农业优化发展区应发挥“领头羊”作用,带动适度发展区早日跨越U型曲线的拐点,实现城镇化带动农业绿色发展;紧凑集约型的城镇化深度推进模式能够显著提升农业低碳TFP,而规模扩张型的城镇化广度推进模式降低了农业低碳TFP;农业低碳技术进步、农村劳动力转移、规模效应、农业产业链延伸和农村居民可支配收入增加是城镇化影响农业低碳TFP的主要途径。
基金supported by the Project of National Natural Science Foundation of China under the grant titled“Research on Intermittent Fault Diagnosis of New Interconnection Networks under Comparative Model”(Approval Number:61862003).
文摘In the context of enterprise systems,intrusion detection(ID)emerges as a critical element driving the digital transformation of enterprises.With systems spanning various sectors of enterprises geographically dispersed,the necessity for seamless information exchange has surged significantly.The existing cross-domain solutions are challenged by such issues as insufficient security,high communication overhead,and a lack of effective update mechanisms,rendering them less feasible for prolonged application on resource-limited devices.This study proposes a new cross-domain collaboration scheme based on federated chains to streamline the server-side workload.Within this framework,individual nodes solely engage in training local data and subsequently amalgamate the final model employing a federated learning algorithm to uphold enterprise systems with efficiency and security.To curtail the resource utilization of blockchains and deter malicious nodes,a node administration module predicated on the workload paradigm is introduced,enabling the release of surplus resources in response to variations in a node’s contribution metric.Upon encountering an intrusion,the system triggers an alert and logs the characteristics of the breach,facilitating a comprehensive global update across all nodes for collective defense.Experimental results across multiple scenarios have verified the security and effectiveness of the proposed solution,with no loss of its recognition accuracy.
