With the flooding of pornographic information on the Internet, how to keep people away from that offensive information is becoming one of the most important research areas in network information security. Some applica...With the flooding of pornographic information on the Internet, how to keep people away from that offensive information is becoming one of the most important research areas in network information security. Some applications which can block or filter such information are used. Approaches in those systems can be roughly classified into two kinds: metadata based and content based. With the development of distributed technologies, content based filtering technologies will play a more and more important role in filtering systems. Keyword matching is a content based method used widely in harmful text filtering. Experiments to evaluate the recall and precision of the method showed that the precision of the method is not satisfactory, though the recall of the method is rather high. According to the results, a new pornographic text filtering model based on reconfirming is put forward. Experiments showed that the model is practical, has less loss of recall than the single keyword matching method, and has higher precision.展开更多
Sensor nodes are easily compromised to malicious attackers due to an open environment. A false injected attack which takes place on application layer is elected by the compromised node. If the false report arrives in ...Sensor nodes are easily compromised to malicious attackers due to an open environment. A false injected attack which takes place on application layer is elected by the compromised node. If the false report arrives in a base station, a false alarm is occurred, and the energy of the nodes is consumed. To detect the false report, statistical en-route filtering method is proposed. In this paper, we proposed the secure path cycle selection method using fuzzy rule-based system to consume effective energy. The method makes balanced energy consumption of each node. Moreover, the lifetime of the whole network will be increased. The base station determines the path cycle using the fuzzy rule-based system. The performance of the proposed method is demonstrated using simulation studies with the three methods.展开更多
为使配电网在虚假数据注入(false data injection,FDI)攻击下仍旧可以获得最优的状态估计,提出了一种新的状态估计算法,提高了配电网抵御FDI攻击的状态估计精度。在相量测量单元(phasor measurement units,PMU)被攻击的情况下,即测量值...为使配电网在虚假数据注入(false data injection,FDI)攻击下仍旧可以获得最优的状态估计,提出了一种新的状态估计算法,提高了配电网抵御FDI攻击的状态估计精度。在相量测量单元(phasor measurement units,PMU)被攻击的情况下,即测量值被篡改,最优卡尔曼估计可以分解为局部状态估计的加权和。该方法在某种意义上不安全,基于局部估计,提出了一种基于凸优化的方法,以取代加权和方法,将局部估计结合成一个安全的状态估计。仿真结果表明:当所有PMU量测设备都是良好时,所提的估计器与卡尔曼估计器的估计结果一致。当PMU设备被攻击造成量测量异常时,提供一个充分条件,在这个条件下安全状态估计器是稳定的。展开更多
文摘With the flooding of pornographic information on the Internet, how to keep people away from that offensive information is becoming one of the most important research areas in network information security. Some applications which can block or filter such information are used. Approaches in those systems can be roughly classified into two kinds: metadata based and content based. With the development of distributed technologies, content based filtering technologies will play a more and more important role in filtering systems. Keyword matching is a content based method used widely in harmful text filtering. Experiments to evaluate the recall and precision of the method showed that the precision of the method is not satisfactory, though the recall of the method is rather high. According to the results, a new pornographic text filtering model based on reconfirming is put forward. Experiments showed that the model is practical, has less loss of recall than the single keyword matching method, and has higher precision.
文摘Sensor nodes are easily compromised to malicious attackers due to an open environment. A false injected attack which takes place on application layer is elected by the compromised node. If the false report arrives in a base station, a false alarm is occurred, and the energy of the nodes is consumed. To detect the false report, statistical en-route filtering method is proposed. In this paper, we proposed the secure path cycle selection method using fuzzy rule-based system to consume effective energy. The method makes balanced energy consumption of each node. Moreover, the lifetime of the whole network will be increased. The base station determines the path cycle using the fuzzy rule-based system. The performance of the proposed method is demonstrated using simulation studies with the three methods.
文摘为使配电网在虚假数据注入(false data injection,FDI)攻击下仍旧可以获得最优的状态估计,提出了一种新的状态估计算法,提高了配电网抵御FDI攻击的状态估计精度。在相量测量单元(phasor measurement units,PMU)被攻击的情况下,即测量值被篡改,最优卡尔曼估计可以分解为局部状态估计的加权和。该方法在某种意义上不安全,基于局部估计,提出了一种基于凸优化的方法,以取代加权和方法,将局部估计结合成一个安全的状态估计。仿真结果表明:当所有PMU量测设备都是良好时,所提的估计器与卡尔曼估计器的估计结果一致。当PMU设备被攻击造成量测量异常时,提供一个充分条件,在这个条件下安全状态估计器是稳定的。
