自动电压控制(Automatic Voltage Control,AVC)是现代电力系统控制的重要功能,厂站端母线电压自动调节功能对电网的安全与稳定有着重要影响。本文介绍了AVC系统基本原理和自动电压控制技术理论依据,根据现场AVC工程技术经验总结,对AVC...自动电压控制(Automatic Voltage Control,AVC)是现代电力系统控制的重要功能,厂站端母线电压自动调节功能对电网的安全与稳定有着重要影响。本文介绍了AVC系统基本原理和自动电压控制技术理论依据,根据现场AVC工程技术经验总结,对AVC系统结构与通信、AVC子站系统信号与数据流向进行了总结与分析设计,提出了厂站端AVC投退与安全逻辑、增减磁控制逻辑的设计方案,并结合华东电网某抽水蓄能电站现场调试工程应用对所提厂站端AVC系统逻辑设计方案进行了验证,在工程上对AVC逻辑设计与应用具有指导意义。展开更多
The backdoor or information leak of Web servers can be detected by using Web Mining techniques on some abnormal Web log and Web application log data. The security of Web servers can be enhanced and the damage of illeg...The backdoor or information leak of Web servers can be detected by using Web Mining techniques on some abnormal Web log and Web application log data. The security of Web servers can be enhanced and the damage of illegal access can be avoided. Firstly, the system for discovering the patterns of information leakages in CGI scripts from Web log data was proposed. Secondly, those patterns for system administrators to modify their codes and enhance their Web site security were provided. The following aspects were described: one is to combine web application log with web log to extract more information,so web data mining could be used to mine web log for discovering the information that firewall and Information Detection System cannot find. Another approach is to propose an operation module of web site to enhance Web site security. In cluster server session, Density -Based Clustering technique is used to reduce resource cost and obtain better efficiency.展开更多
文摘自动电压控制(Automatic Voltage Control,AVC)是现代电力系统控制的重要功能,厂站端母线电压自动调节功能对电网的安全与稳定有着重要影响。本文介绍了AVC系统基本原理和自动电压控制技术理论依据,根据现场AVC工程技术经验总结,对AVC系统结构与通信、AVC子站系统信号与数据流向进行了总结与分析设计,提出了厂站端AVC投退与安全逻辑、增减磁控制逻辑的设计方案,并结合华东电网某抽水蓄能电站现场调试工程应用对所提厂站端AVC系统逻辑设计方案进行了验证,在工程上对AVC逻辑设计与应用具有指导意义。
文摘The backdoor or information leak of Web servers can be detected by using Web Mining techniques on some abnormal Web log and Web application log data. The security of Web servers can be enhanced and the damage of illegal access can be avoided. Firstly, the system for discovering the patterns of information leakages in CGI scripts from Web log data was proposed. Secondly, those patterns for system administrators to modify their codes and enhance their Web site security were provided. The following aspects were described: one is to combine web application log with web log to extract more information,so web data mining could be used to mine web log for discovering the information that firewall and Information Detection System cannot find. Another approach is to propose an operation module of web site to enhance Web site security. In cluster server session, Density -Based Clustering technique is used to reduce resource cost and obtain better efficiency.
