Greater complexity and interconnectivity across systems embracing electrical power technologies has meant that cyber-security issues have attracted significant attention. In this paper a simulation environment for int...Greater complexity and interconnectivity across systems embracing electrical power technologies has meant that cyber-security issues have attracted significant attention. In this paper a simulation environment for intrusion detection system in IEC 61850 standard-based substation automation system is provided to test simulated attacks on IEDs （intelligent electronic devices）. Intrusion detection is the process of detecting malicious attacker, so it is an effective and mature security mechanism to protect electrical facility. However, it is not harnessed when securing IEC 61850 automated substation. To prove the detection capability of the system testing environment was developed to analyze and test attacks simulated with different test cases. It shows that the simulation environment works accordingly to various network traffic scenarios and eventually proves the functionality of intrusion detection system to be later deployed in the real IEC 61850 based substation automation system site.展开更多
Although numerical simulation tools are now very powerful,the development of analytical models is very important for the prediction of the mechanical behaviour of line contact structures for deeply understanding conta...Although numerical simulation tools are now very powerful,the development of analytical models is very important for the prediction of the mechanical behaviour of line contact structures for deeply understanding contact problems and engineering applications.For the line contact structures widely used in the engineering field,few analytical models are available for predicting the mechanical behaviour when the structures deform plastically,as the classic Hertz’s theory would be invalid.Thus,the present study proposed an elastic-plastic model for line contact structures based on the understanding of the yield mechanism.A mathematical expression describing the global relationship between load history and contact width evolution of line contact structures was obtained.The proposed model was verified through an actual line contact test and a corresponding numerical simulation.The results confirmed that this model can be used to accurately predict the elastic-plastic mechanical behaviour of a line contact structure.展开更多
We extended an improved version of the discrete particle swarm optimization (DPSO) algorithm proposed by Liao et al.(2007) to solve the dynamic facility layout problem (DFLP). A computational study was performed with ...We extended an improved version of the discrete particle swarm optimization (DPSO) algorithm proposed by Liao et al.(2007) to solve the dynamic facility layout problem (DFLP). A computational study was performed with the existing heuristic algorithms, including the dynamic programming (DP), genetic algorithm (GA), simulated annealing (SA), hybrid ant system (HAS), hybrid simulated annealing (SA-EG), hybrid genetic algorithms (NLGA and CONGA). The proposed DPSO algorithm, SA, HAS, GA, DP, SA-EG, NLGA, and CONGA obtained the best solutions for 33, 24, 20, 10, 12, 20, 5, and 2 of the 48 problems from (Balakrishnan and Cheng, 2000), respectively. These results show that the DPSO is very effective in dealing with the DFLP. The extended DPSO also has very good computational efficiency when the problem size increases.展开更多
文摘Greater complexity and interconnectivity across systems embracing electrical power technologies has meant that cyber-security issues have attracted significant attention. In this paper a simulation environment for intrusion detection system in IEC 61850 standard-based substation automation system is provided to test simulated attacks on IEDs （intelligent electronic devices）. Intrusion detection is the process of detecting malicious attacker, so it is an effective and mature security mechanism to protect electrical facility. However, it is not harnessed when securing IEC 61850 automated substation. To prove the detection capability of the system testing environment was developed to analyze and test attacks simulated with different test cases. It shows that the simulation environment works accordingly to various network traffic scenarios and eventually proves the functionality of intrusion detection system to be later deployed in the real IEC 61850 based substation automation system site.
基金supported by the National Natural Science Foundation of China(Grant Nos.11602022,and 11727801)the opening projects from the State Key Laboratory of Explosion Science and Technology(Grant No.KFJJ16-05M)the State Key Laboratory of Earthquake Dynamics(Grant No.LED2016B02)
文摘Although numerical simulation tools are now very powerful,the development of analytical models is very important for the prediction of the mechanical behaviour of line contact structures for deeply understanding contact problems and engineering applications.For the line contact structures widely used in the engineering field,few analytical models are available for predicting the mechanical behaviour when the structures deform plastically,as the classic Hertz’s theory would be invalid.Thus,the present study proposed an elastic-plastic model for line contact structures based on the understanding of the yield mechanism.A mathematical expression describing the global relationship between load history and contact width evolution of line contact structures was obtained.The proposed model was verified through an actual line contact test and a corresponding numerical simulation.The results confirmed that this model can be used to accurately predict the elastic-plastic mechanical behaviour of a line contact structure.
文摘We extended an improved version of the discrete particle swarm optimization (DPSO) algorithm proposed by Liao et al.(2007) to solve the dynamic facility layout problem (DFLP). A computational study was performed with the existing heuristic algorithms, including the dynamic programming (DP), genetic algorithm (GA), simulated annealing (SA), hybrid ant system (HAS), hybrid simulated annealing (SA-EG), hybrid genetic algorithms (NLGA and CONGA). The proposed DPSO algorithm, SA, HAS, GA, DP, SA-EG, NLGA, and CONGA obtained the best solutions for 33, 24, 20, 10, 12, 20, 5, and 2 of the 48 problems from (Balakrishnan and Cheng, 2000), respectively. These results show that the DPSO is very effective in dealing with the DFLP. The extended DPSO also has very good computational efficiency when the problem size increases.
