针对目前有源电力滤波器(APF)控制系统数据采集实时性不高,数据传输量有限的问题,设计了基于Lw IP的APF实时数据采集监控系统。文中详细介绍了系统下位机与上位机之间数据传输的时序控制,包括DSP数据组织传输,ARM数据接收调度以及上位...针对目前有源电力滤波器(APF)控制系统数据采集实时性不高,数据传输量有限的问题,设计了基于Lw IP的APF实时数据采集监控系统。文中详细介绍了系统下位机与上位机之间数据传输的时序控制,包括DSP数据组织传输,ARM数据接收调度以及上位机数据接收与下发等软件功能的实现。同时系统还实现了APF运行时通过上位机设置控制参数的功能。通过实验,验证了系统控制参数下发以及32 k Hz采样频率下15个数据实时更新的可行性与有效性。展开更多
The local-world (LW) evolving network model shows a transition for the degree distribution between the exponential and power-law distributions, depending on the LW size. Cascading failures under intentional attacks in...The local-world (LW) evolving network model shows a transition for the degree distribution between the exponential and power-law distributions, depending on the LW size. Cascading failures under intentional attacks in LW network models with different LW sizes were investigated using the cascading failures load model. We found that the LW size has a significant impact on the network's robustness against deliberate attacks. It is much easier to trigger cascading failures in LW evolving networks with a larger LW size. Therefore, to avoid cascading failures in real networks with local preferential attachment such as the Internet, the World Trade Web and the multi-agent system, the LW size should be as small as possible.展开更多
The storage, longitudinal distribution and recruitment processes of in-stream large wood (LW) were studied comparing channel segments draining four Chilean mountain catchments with different land use. The segments wer...The storage, longitudinal distribution and recruitment processes of in-stream large wood (LW) were studied comparing channel segments draining four Chilean mountain catchments with different land use. The segments were divided into relatively uniform reaches of different lengths and surveyed for LW (piece dimensions, position in the channel, orientation to flow and aggregation) and stream morphology (slope and bank full channel width and depth) characterizations. LW volume stored in the Pichun, El Toro and Vuelta de Zorra study channels are within the range informed in international researches from streams draining catchments with similar forest covers. However, the 1057 m3/ha of LW stored in Tres Arroyos is extremely high and in the same order of magnitude than the reports from old-growth forests in the Pacific Northwest of USA. The size of the area that can potentially provide wood to streams depends on the wood supply mechanisms within any catchment, and the LW stored in the study segments increases as the size of this area increases. This study aims to contribute to the knowledge on the effects of LW in mountain channels, gathering new information and expanding investigations developed in Chile since 2008. This research was carried out within the framework of Project FONDECYT 11106209.展开更多
文摘针对目前有源电力滤波器(APF)控制系统数据采集实时性不高,数据传输量有限的问题,设计了基于Lw IP的APF实时数据采集监控系统。文中详细介绍了系统下位机与上位机之间数据传输的时序控制,包括DSP数据组织传输,ARM数据接收调度以及上位机数据接收与下发等软件功能的实现。同时系统还实现了APF运行时通过上位机设置控制参数的功能。通过实验,验证了系统控制参数下发以及32 k Hz采样频率下15个数据实时更新的可行性与有效性。
基金the National Basic Research Program (973) of China (No. 2004CB217902)the National Natural Science Foundation of China (Nos. 60421002 and 60804045)the Postdoctoral Science Foundation of China (No. 20070421163)
文摘The local-world (LW) evolving network model shows a transition for the degree distribution between the exponential and power-law distributions, depending on the LW size. Cascading failures under intentional attacks in LW network models with different LW sizes were investigated using the cascading failures load model. We found that the LW size has a significant impact on the network's robustness against deliberate attacks. It is much easier to trigger cascading failures in LW evolving networks with a larger LW size. Therefore, to avoid cascading failures in real networks with local preferential attachment such as the Internet, the World Trade Web and the multi-agent system, the LW size should be as small as possible.
文摘The storage, longitudinal distribution and recruitment processes of in-stream large wood (LW) were studied comparing channel segments draining four Chilean mountain catchments with different land use. The segments were divided into relatively uniform reaches of different lengths and surveyed for LW (piece dimensions, position in the channel, orientation to flow and aggregation) and stream morphology (slope and bank full channel width and depth) characterizations. LW volume stored in the Pichun, El Toro and Vuelta de Zorra study channels are within the range informed in international researches from streams draining catchments with similar forest covers. However, the 1057 m3/ha of LW stored in Tres Arroyos is extremely high and in the same order of magnitude than the reports from old-growth forests in the Pacific Northwest of USA. The size of the area that can potentially provide wood to streams depends on the wood supply mechanisms within any catchment, and the LW stored in the study segments increases as the size of this area increases. This study aims to contribute to the knowledge on the effects of LW in mountain channels, gathering new information and expanding investigations developed in Chile since 2008. This research was carried out within the framework of Project FONDECYT 11106209.
