In this paper security systems deployed over an area are regarded abstractly as a diagram of security network. We propose the Neyman-Pearson protection model for security systems, which can be used to determine the pr...In this paper security systems deployed over an area are regarded abstractly as a diagram of security network. We propose the Neyman-Pearson protection model for security systems, which can be used to determine the protection probability of a security system and find the weakest breach path of a security network. We present the weakest breach path problem formulation, which is defined by the breach protection probability of an unauthorized target passing through a guard field, and provide a solution for this problem by using the Dijkstra’s shortest path algorithm. Finally we study the variation of the breach protection probability with the change of the parameters of the model.展开更多
Cathodic protection is an effective electrochemical technique for preventing corrosion of metallic structures, for large structures like piles network impressed current cathodic protection (ICCP) system is usually pre...Cathodic protection is an effective electrochemical technique for preventing corrosion of metallic structures, for large structures like piles network impressed current cathodic protection (ICCP) system is usually preferred. The main aim of this study is to obtain the optimum protection potential that would provide a full cathodic protection for steel piles net-work immersed in sea water at Al-Zubair harbor. The effect of one immeasurable factor (path of anode (χ1)) and two measurable factors (position of anode (χ2) and voltage of power supply (χ3)) on protection potential are studied. Each factor has three different levels (high, medium, and low). Twenty-seven experiments were conducted based on a full factorial design of experiments. The results show that, a sufficient protection for three cathodes can be provided through the electrical circuit connecting them within the appropriate geometric shape.The protection potential is icreased with increasing the voltage of power supply and decreasing of distance between the anode and cathodes (piles network).展开更多
The path protection approach is widely investigated as a survivability solution for GMPLS networks, which has the advantage of efficient capacity utilization. However, there is a problem of the path protection approac...The path protection approach is widely investigated as a survivability solution for GMPLS networks, which has the advantage of efficient capacity utilization. However, there is a problem of the path protection approach that searching a disjoint backup path for a primary path is often unsuccessful. In order to resolve this problem, an integrated dynamic shared protection （IDSP） algorithm is proposed. The main idea of the proposed algorithm is that the path protection approach is first used to establish a backup path for the primary path; if the establishment is unsuccessful, then the primary path is dynamically divided into segments whose hop count are not fixed but not more than the limitation calculated by the equations introduced. In this proposal, backup bandwidth sharing is allowed to improve the capacity utilization ratio, which makes the link cost function quite different from previous ones. Simulation experiments are presented to demonstrate the efficiency of the proposed method compared with previous methods. Numerical results show that IDSP can not only achieve low protection failure probability but can also gain a better tradeoff between the protection overbuild and the average recovery time.展开更多
文摘In this paper security systems deployed over an area are regarded abstractly as a diagram of security network. We propose the Neyman-Pearson protection model for security systems, which can be used to determine the protection probability of a security system and find the weakest breach path of a security network. We present the weakest breach path problem formulation, which is defined by the breach protection probability of an unauthorized target passing through a guard field, and provide a solution for this problem by using the Dijkstra’s shortest path algorithm. Finally we study the variation of the breach protection probability with the change of the parameters of the model.
文摘Cathodic protection is an effective electrochemical technique for preventing corrosion of metallic structures, for large structures like piles network impressed current cathodic protection (ICCP) system is usually preferred. The main aim of this study is to obtain the optimum protection potential that would provide a full cathodic protection for steel piles net-work immersed in sea water at Al-Zubair harbor. The effect of one immeasurable factor (path of anode (χ1)) and two measurable factors (position of anode (χ2) and voltage of power supply (χ3)) on protection potential are studied. Each factor has three different levels (high, medium, and low). Twenty-seven experiments were conducted based on a full factorial design of experiments. The results show that, a sufficient protection for three cathodes can be provided through the electrical circuit connecting them within the appropriate geometric shape.The protection potential is icreased with increasing the voltage of power supply and decreasing of distance between the anode and cathodes (piles network).
基金supported by the National Natural Science Foundation of China (60673142)Applied Basic Research Project of Sichuan Province (2006J13-067).
文摘The path protection approach is widely investigated as a survivability solution for GMPLS networks, which has the advantage of efficient capacity utilization. However, there is a problem of the path protection approach that searching a disjoint backup path for a primary path is often unsuccessful. In order to resolve this problem, an integrated dynamic shared protection （IDSP） algorithm is proposed. The main idea of the proposed algorithm is that the path protection approach is first used to establish a backup path for the primary path; if the establishment is unsuccessful, then the primary path is dynamically divided into segments whose hop count are not fixed but not more than the limitation calculated by the equations introduced. In this proposal, backup bandwidth sharing is allowed to improve the capacity utilization ratio, which makes the link cost function quite different from previous ones. Simulation experiments are presented to demonstrate the efficiency of the proposed method compared with previous methods. Numerical results show that IDSP can not only achieve low protection failure probability but can also gain a better tradeoff between the protection overbuild and the average recovery time.
