Evaluation of IEEE 802.11 Mobile Ad Hoc Networks (MANET) security issues becomes significant concern for researchers since Denial of Service (DoS) attacks are recognized as one of the most harmful threats. A variety o...Evaluation of IEEE 802.11 Mobile Ad Hoc Networks (MANET) security issues becomes significant concern for researchers since Denial of Service (DoS) attacks are recognized as one of the most harmful threats. A variety of security mechanisms are proposed to solve security dilemma in MANETs against different layers of DoS attacks. Physical Layer jamming attacks exhaust the victim’s network resources such as bandwidth, computing power, battery, etc. Unified Security Mechanism (USM) and Rate Adaptation Scheme (RAS) are two of the proposed methods by researchers against DoS attacks. USM and RAS mechanisms are simulated through OPNET simulator and Jamming Attack is generated on the network for each security mechanisms to compare specific performance metrics on the network.展开更多
A unified second-order moment (USM) turbulence-chemistry model for simulating NOx formation in turbulent combustion is proposed.All of correlations,including the correlation of the reaction-rate coefficient fluctuatio...A unified second-order moment (USM) turbulence-chemistry model for simulating NOx formation in turbulent combustion is proposed.All of correlations,including the correlation of the reaction-rate coefficient fluctuation with the concentration fluctuation,are closed by the transport equations in the same form.This model discards the approximation of series expansion of the exponential function or the approximation of using the product of several 1-D PDF's instead of a joint PDF.It is much simpler than other refined models,such as the PDF transport equation model and the conditional moment closure model.The proposed model is used to simulate methane-air swirling turbulent combustion and NOx formation.The prediction results are in good agreement with the experimental results.展开更多
文摘Evaluation of IEEE 802.11 Mobile Ad Hoc Networks (MANET) security issues becomes significant concern for researchers since Denial of Service (DoS) attacks are recognized as one of the most harmful threats. A variety of security mechanisms are proposed to solve security dilemma in MANETs against different layers of DoS attacks. Physical Layer jamming attacks exhaust the victim’s network resources such as bandwidth, computing power, battery, etc. Unified Security Mechanism (USM) and Rate Adaptation Scheme (RAS) are two of the proposed methods by researchers against DoS attacks. USM and RAS mechanisms are simulated through OPNET simulator and Jamming Attack is generated on the network for each security mechanisms to compare specific performance metrics on the network.
文摘A unified second-order moment (USM) turbulence-chemistry model for simulating NOx formation in turbulent combustion is proposed.All of correlations,including the correlation of the reaction-rate coefficient fluctuation with the concentration fluctuation,are closed by the transport equations in the same form.This model discards the approximation of series expansion of the exponential function or the approximation of using the product of several 1-D PDF's instead of a joint PDF.It is much simpler than other refined models,such as the PDF transport equation model and the conditional moment closure model.The proposed model is used to simulate methane-air swirling turbulent combustion and NOx formation.The prediction results are in good agreement with the experimental results.
