Land use/land cover change (LUCC) is a focus of the research of global environmental changes. The middle and upper reaches of the Yangtze River, which are the most ecologically fragile mountainous area in China as wel...Land use/land cover change (LUCC) is a focus of the research of global environmental changes. The middle and upper reaches of the Yangtze River, which are the most ecologically fragile mountainous area in China as well as one of the areas in China with most notable LUCC, have been on the Chinese Government's list of priority areas for ecological restoration. This paper is to reveal the trend of LUCC and the ecological degradation arising from it, and to provide a basis for the future sustainable use of land resources in the region based on a detailed analysis of Yiliang County. Based on the county's land use/cover maps in 1960, 1980 and 2000 drawn with the aid of aerial photograph interpretation, field investigation and GIS based spatial-temporal data analysis, LUCC during 1960~2000 period and the ecological degradation arising from it were analyzed. Using the Markv model, the paper brings out a forecast of what the county's LUCC would be like if the county's current land use continues, as well as the reasons and countermeasures for restoring degraded ecosystems.展开更多
In recent years, the bridge safety monitoring has been paid more attention in engineering field. How- ever, the financial and material resources as well as human resources were costly for the traditional monitoring me...In recent years, the bridge safety monitoring has been paid more attention in engineering field. How- ever, the financial and material resources as well as human resources were costly for the traditional monitoring means. Besides, the traditional means of monitoring were low in accuracy. From an engineering example, based on neural network method and historical data of the bridge monitoring to construct the BP neural network model with dual hidden layer strueture, the bridge temperature field and its effect on the behavior of bridge deflection are forecasted. The fact indicates that the predicted biggest error is 3.06% of the bridge temperature field and the bridge deflection behavior under temperature field affected is 2. 17% by the method of the BP neural net-work, which fully meet the precision requirements of the construction with practical value.展开更多
While the threat of war has decreased, there have appeared intricate security issues that affect all aspects of human life, breaking through various defenses and threatening the well being of all actors in the contemp...While the threat of war has decreased, there have appeared intricate security issues that affect all aspects of human life, breaking through various defenses and threatening the well being of all actors in the contemporary world, including nations, groups and individuals. This risky situation calls for a new security concept, one that transcends traditional state centrism, national supremacy and coercion. The new security concept, which should assimilate the general theory of grand strategy,focuses on a vision that spans time and space, valuing humankind as it exists as one of the dynamic factors of nature and society. The essentials of the new security concept are to recognize balanced development as the substance of security and to govern national strength and the application of means and tactics. It aims at realizing comprehensive security across various social fields within states, to achieve mutual security among national, international and individual actors, as well as harmony between man and nature, continuous security leading to lasting and universal peace in the future.展开更多
Network intrusion forensics is an important extension to present security infrastructure,and is becoming the focus of forensics research field.However,comparison with sophisticated multi-stage attacks and volume of se...Network intrusion forensics is an important extension to present security infrastructure,and is becoming the focus of forensics research field.However,comparison with sophisticated multi-stage attacks and volume of sensor data,current practices in network forensic analysis are to manually examine,an error prone,labor-intensive and time consuming process.To solve these problems,in this paper we propose a digital evidence fusion method for network forensics with Dempster-Shafer theory that can detect efficiently computer crime in networked environments,and fuse digital evidence from different sources such as hosts and sub-networks automatically.In the end,we evaluate the method on well-known KDD Cup1999 dataset.The results prove our method is very effective for real-time network forensics,and can provide comprehensible messages for a forensic investigators.展开更多
Damage on surfaces often compromises the efficiency of some types of energy production, the safety and reliability of components, and ultimately increases costs. The environment can degrade the structural integrity of...Damage on surfaces often compromises the efficiency of some types of energy production, the safety and reliability of components, and ultimately increases costs. The environment can degrade the structural integrity of surfaces in service by the accumulation of large numbers of small destructive events, which based on the Central Limit Theorem leads to a Gaussian distribution of pit depth. In order to develop safety envelopes relating fracture loci with topological parameters of a brittle material, scatter plots were obtained and analyzed. Starting with an engineering surface, after 6 to 9 micrometers of average degradation depth, safety envelopes could be developed using average roughness and two other proposed parameters. Interestingly, maximum pit depth showed very low correlation with the location of fracture, at the early stage of degradation studied. This is attributed to relaxation of stress concentration at a given pit location due to the assuaging effect caused by neighboring pits. Additionally, energy at fracture was obtained, and a maximum relaxation region was observed. Analytical and experimental study of this region, as well as ductility effects are currently under research.展开更多
The thesis researches the safety infonnation and control system （SICS） design principle and introduces engineering application in CPR1000 nuclear power station in China. The SICS provides sufficient control and moni...The thesis researches the safety infonnation and control system （SICS） design principle and introduces engineering application in CPR1000 nuclear power station in China. The SICS provides sufficient control and monitoring means to bring and maintain the plant in a safe state as a backup of main computerized control mean （MCM）, in any plant conditions that are probable during a planed or unplanned unavailability of the MCM. The successful engineering applications of SICS in different digital I＆C system platform are introduced in the paper. The thesis gives the research conclusion for new general SICS of digital I＆C system.展开更多
基金the result of the project(No.400610o6)funded by the National Natural Science Foundation of China.
文摘Land use/land cover change (LUCC) is a focus of the research of global environmental changes. The middle and upper reaches of the Yangtze River, which are the most ecologically fragile mountainous area in China as well as one of the areas in China with most notable LUCC, have been on the Chinese Government's list of priority areas for ecological restoration. This paper is to reveal the trend of LUCC and the ecological degradation arising from it, and to provide a basis for the future sustainable use of land resources in the region based on a detailed analysis of Yiliang County. Based on the county's land use/cover maps in 1960, 1980 and 2000 drawn with the aid of aerial photograph interpretation, field investigation and GIS based spatial-temporal data analysis, LUCC during 1960~2000 period and the ecological degradation arising from it were analyzed. Using the Markv model, the paper brings out a forecast of what the county's LUCC would be like if the county's current land use continues, as well as the reasons and countermeasures for restoring degraded ecosystems.
文摘In recent years, the bridge safety monitoring has been paid more attention in engineering field. How- ever, the financial and material resources as well as human resources were costly for the traditional monitoring means. Besides, the traditional means of monitoring were low in accuracy. From an engineering example, based on neural network method and historical data of the bridge monitoring to construct the BP neural network model with dual hidden layer strueture, the bridge temperature field and its effect on the behavior of bridge deflection are forecasted. The fact indicates that the predicted biggest error is 3.06% of the bridge temperature field and the bridge deflection behavior under temperature field affected is 2. 17% by the method of the BP neural net-work, which fully meet the precision requirements of the construction with practical value.
文摘While the threat of war has decreased, there have appeared intricate security issues that affect all aspects of human life, breaking through various defenses and threatening the well being of all actors in the contemporary world, including nations, groups and individuals. This risky situation calls for a new security concept, one that transcends traditional state centrism, national supremacy and coercion. The new security concept, which should assimilate the general theory of grand strategy,focuses on a vision that spans time and space, valuing humankind as it exists as one of the dynamic factors of nature and society. The essentials of the new security concept are to recognize balanced development as the substance of security and to govern national strength and the application of means and tactics. It aims at realizing comprehensive security across various social fields within states, to achieve mutual security among national, international and individual actors, as well as harmony between man and nature, continuous security leading to lasting and universal peace in the future.
基金supported by the National Natural Science Foundation of China under Grant No.60903166 the National High Technology Research and Development Program of China（863 Program） under Grants No.2012AA012506,No.2012AA012901,No.2012AA012903+9 种基金 Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant No.20121103120032 the Humanity and Social Science Youth Foundation of Ministry of Education of China under Grant No.13YJCZH065 the Opening Project of Key Lab of Information Network Security of Ministry of Public Security（The Third Research Institute of Ministry of Public Security） under Grant No.C13613 the China Postdoctoral Science Foundation General Program of Science and Technology Development Project of Beijing Municipal Education Commission of China under Grant No.km201410005012 the Research on Education and Teaching of Beijing University of Technology under Grant No.ER2013C24 the Beijing Municipal Natural Science Foundation Sponsored by Hunan Postdoctoral Scientific Program Open Research Fund of Beijing Key Laboratory of Trusted Computing Funds for the Central Universities, Contract No.2012JBM030
文摘Network intrusion forensics is an important extension to present security infrastructure,and is becoming the focus of forensics research field.However,comparison with sophisticated multi-stage attacks and volume of sensor data,current practices in network forensic analysis are to manually examine,an error prone,labor-intensive and time consuming process.To solve these problems,in this paper we propose a digital evidence fusion method for network forensics with Dempster-Shafer theory that can detect efficiently computer crime in networked environments,and fuse digital evidence from different sources such as hosts and sub-networks automatically.In the end,we evaluate the method on well-known KDD Cup1999 dataset.The results prove our method is very effective for real-time network forensics,and can provide comprehensible messages for a forensic investigators.
文摘Damage on surfaces often compromises the efficiency of some types of energy production, the safety and reliability of components, and ultimately increases costs. The environment can degrade the structural integrity of surfaces in service by the accumulation of large numbers of small destructive events, which based on the Central Limit Theorem leads to a Gaussian distribution of pit depth. In order to develop safety envelopes relating fracture loci with topological parameters of a brittle material, scatter plots were obtained and analyzed. Starting with an engineering surface, after 6 to 9 micrometers of average degradation depth, safety envelopes could be developed using average roughness and two other proposed parameters. Interestingly, maximum pit depth showed very low correlation with the location of fracture, at the early stage of degradation studied. This is attributed to relaxation of stress concentration at a given pit location due to the assuaging effect caused by neighboring pits. Additionally, energy at fracture was obtained, and a maximum relaxation region was observed. Analytical and experimental study of this region, as well as ductility effects are currently under research.
文摘The thesis researches the safety infonnation and control system （SICS） design principle and introduces engineering application in CPR1000 nuclear power station in China. The SICS provides sufficient control and monitoring means to bring and maintain the plant in a safe state as a backup of main computerized control mean （MCM）, in any plant conditions that are probable during a planed or unplanned unavailability of the MCM. The successful engineering applications of SICS in different digital I＆C system platform are introduced in the paper. The thesis gives the research conclusion for new general SICS of digital I＆C system.
