Aim To define a mixed redundant model(MRM), improving the reliability of C 3I system. Methods The model combined the technology characters of two? unit system with one warm stand by unit and function substitute s...Aim To define a mixed redundant model(MRM), improving the reliability of C 3I system. Methods The model combined the technology characters of two? unit system with one warm stand by unit and function substitute system. The reliability and availability equations of MRM were deduced. Results and Conclusion Compared with several other reliability models, it has obvious effect upon improving the system reliability. The effect? cost rate is very high among these models. The model can be used in reliability design, evaluation and check of C 3I system. Only a little attached cost is needed to improve C 3I system reliability effectively.展开更多
The grey quasi-preferred analysis (GQPA) is one of important methods for realizing system analysis to conquer the limitations of the existing GQPA model, without any considerations to the difference of the different b...The grey quasi-preferred analysis (GQPA) is one of important methods for realizing system analysis to conquer the limitations of the existing GQPA model, without any considerations to the difference of the different behavioral factor′s importance. It could not be used to analyze the complex system with multi-hierarchy correlation factors, the weighted synthetic method for calculating abstract incidence degrees between the system beha-vioral characteristics and correlative factors in different hierarchies is given out,and the hierarchic grey quasi-preferred analysis (HGQPA) model is established. The effectiveness of the HGQPA model is tested by the scientific-technical system of Jiangsu Province. The depth and the range of the application of GQPA are developed, and the HGQPA model is regarded as a new approach to systemically analyze the complex systems with multi-hierarchy correlation factors.展开更多
Network structures and human behaviors are considered as two important factors in virus defense currently. However, due to ignorance of network security, normal users usually take simple activities, such as reinstalli...Network structures and human behaviors are considered as two important factors in virus defense currently. However, due to ignorance of network security, normal users usually take simple activities, such as reinstalling computer system, or using the computer recovery system to clear virus. How system recovery influences virus spreading is not taken into consideration currently. In this paper, a new virus propagation model considering the system recovery is proposed first, and then in its steady-state analysis, the virus propagation steady time and steady states are deduced. Experiment results show that models considering system recovery can effectively restrain virus propagation. Furthermore, algorithm with system recovery in BA scale-free network is proposed. Simulation result turns out that target immunization strategy with system recovery works better than traditional ones in BA network.展开更多
By taking a 2.3 MW double-fed asynchronous generator as an example,a new method for fast simulation analysis of ventilation cooling system inside generator is proposed based on the one-dimensional simulation software ...By taking a 2.3 MW double-fed asynchronous generator as an example,a new method for fast simulation analysis of ventilation cooling system inside generator is proposed based on the one-dimensional simulation software FLOWMASTER.The thermal-fluid coupling simulation model of ventilation cooling system inside generator is established.Under the stable running state of the generator,the flow velocity distribution and temperature rise of the key parts of the generator are analyzed.The results prove that the ventilation structure design of the generator meets the temperature rise limit.The simulation results are compared with the theoretical calculation results and the experimental results,which verify the correctness of the thermal-fluid coupling simulation method proposed in this paper.展开更多
In order to establish an effective wireless communication system in an underground coal-mine environment, the propagation of radio waves through a rectangular-like mine tunnel was investigated by jointly, considering ...In order to establish an effective wireless communication system in an underground coal-mine environment, the propagation of radio waves through a rectangular-like mine tunnel was investigated by jointly, considering both the dielectric constant and the reflectance of a mine tunnel. By combining free space and modified waveguide propagation models, we propose a new hybrid propagation model based on ray tracing. Simulation results have shown the effectiveness of establishing a wireless Local Area Network (LAN) in this coal-mine environment. The results of this research will be very useful as a guide in the design and development of tunnel wireless LAN systems.展开更多
文摘Aim To define a mixed redundant model(MRM), improving the reliability of C 3I system. Methods The model combined the technology characters of two? unit system with one warm stand by unit and function substitute system. The reliability and availability equations of MRM were deduced. Results and Conclusion Compared with several other reliability models, it has obvious effect upon improving the system reliability. The effect? cost rate is very high among these models. The model can be used in reliability design, evaluation and check of C 3I system. Only a little attached cost is needed to improve C 3I system reliability effectively.
文摘The grey quasi-preferred analysis (GQPA) is one of important methods for realizing system analysis to conquer the limitations of the existing GQPA model, without any considerations to the difference of the different behavioral factor′s importance. It could not be used to analyze the complex system with multi-hierarchy correlation factors, the weighted synthetic method for calculating abstract incidence degrees between the system beha-vioral characteristics and correlative factors in different hierarchies is given out,and the hierarchic grey quasi-preferred analysis (HGQPA) model is established. The effectiveness of the HGQPA model is tested by the scientific-technical system of Jiangsu Province. The depth and the range of the application of GQPA are developed, and the HGQPA model is regarded as a new approach to systemically analyze the complex systems with multi-hierarchy correlation factors.
基金supported by China NSF(61572222, 61272405, 61272033, 61272451, 61472121)Fundamental Research Funds for the Central Universities and the open research fund of Zhejiang Provincial Key Lab of Data StorageTransmission Technology, Hangzhou Dianzi University(No. 201301)
文摘Network structures and human behaviors are considered as two important factors in virus defense currently. However, due to ignorance of network security, normal users usually take simple activities, such as reinstalling computer system, or using the computer recovery system to clear virus. How system recovery influences virus spreading is not taken into consideration currently. In this paper, a new virus propagation model considering the system recovery is proposed first, and then in its steady-state analysis, the virus propagation steady time and steady states are deduced. Experiment results show that models considering system recovery can effectively restrain virus propagation. Furthermore, algorithm with system recovery in BA scale-free network is proposed. Simulation result turns out that target immunization strategy with system recovery works better than traditional ones in BA network.
文摘By taking a 2.3 MW double-fed asynchronous generator as an example,a new method for fast simulation analysis of ventilation cooling system inside generator is proposed based on the one-dimensional simulation software FLOWMASTER.The thermal-fluid coupling simulation model of ventilation cooling system inside generator is established.Under the stable running state of the generator,the flow velocity distribution and temperature rise of the key parts of the generator are analyzed.The results prove that the ventilation structure design of the generator meets the temperature rise limit.The simulation results are compared with the theoretical calculation results and the experimental results,which verify the correctness of the thermal-fluid coupling simulation method proposed in this paper.
基金supported by the National Natural Science Foundation of China (No.10974044)the Open Project of the Key Lab of the Technique of Electricity Transmission, Distribution and Conservation in Changzhou, China
文摘In order to establish an effective wireless communication system in an underground coal-mine environment, the propagation of radio waves through a rectangular-like mine tunnel was investigated by jointly, considering both the dielectric constant and the reflectance of a mine tunnel. By combining free space and modified waveguide propagation models, we propose a new hybrid propagation model based on ray tracing. Simulation results have shown the effectiveness of establishing a wireless Local Area Network (LAN) in this coal-mine environment. The results of this research will be very useful as a guide in the design and development of tunnel wireless LAN systems.
