Although there exist a few good schemes to protect the kernel hooks of operating systems, attackers are still able to circumvent existing defense mechanisms with spurious context infonmtion. To address this challenge,...Although there exist a few good schemes to protect the kernel hooks of operating systems, attackers are still able to circumvent existing defense mechanisms with spurious context infonmtion. To address this challenge, this paper proposes a framework, called HooklMA, to detect compromised kernel hooks by using hardware debugging features. The key contribution of the work is that context information is captured from hardware instead of from relatively vulnerable kernel data. Using commodity hardware, a proof-of-concept pro- totype system of HooklMA has been developed. This prototype handles 3 082 dynamic control-flow transfers with related hooks in the kernel space. Experiments show that HooklMA is capable of detecting compomised kernel hooks caused by kernel rootkits. Performance evaluations with UnixBench indicate that runtirre overhead introduced by HooklMA is about 21.5%.展开更多
A mathematical model is developed based on a simplified mechanism of anaerobic digestion. The main objective is to quantitatively analyze the digestion process to optimize operating conditions and maintenance of this ...A mathematical model is developed based on a simplified mechanism of anaerobic digestion. The main objective is to quantitatively analyze the digestion process to optimize operating conditions and maintenance of this equipment, which could be used to test different materials and be able to apply these results to the possible scaling to bio-digesters installed in the field. The experiments were carried out in a hybrid system bio-digester photovoltaic cells. The bio-digester is made of stainless steel with dimensions to treat an average of 10 kg of raw material and produce biogas from different organic materials. The reactor has been conditioned with temperature sensors, pressure and methane gas that allow monitoring the concentration of the gas and the conditions of operation during the time of digestion. The system has a photovoltaic array to provide the energy required to keep the temperature constant, The experiment was conducted using materials such as goat manure mixed with household waste, and various formulations of these materials were prepared. The experimental results were used to test the mathematical model.展开更多
基金The authors would like to thank the anonymous reviewers for their insightful corrnlents that have helped improve the presentation of this paper. The work was supported partially by the National Natural Science Foundation of China under Grants No. 61070192, No.91018008, No. 61170240 the National High-Tech Research Development Program of China under Grant No. 2007AA01ZA14 the Natural Science Foundation of Beijing un- der Grant No. 4122041.
文摘Although there exist a few good schemes to protect the kernel hooks of operating systems, attackers are still able to circumvent existing defense mechanisms with spurious context infonmtion. To address this challenge, this paper proposes a framework, called HooklMA, to detect compromised kernel hooks by using hardware debugging features. The key contribution of the work is that context information is captured from hardware instead of from relatively vulnerable kernel data. Using commodity hardware, a proof-of-concept pro- totype system of HooklMA has been developed. This prototype handles 3 082 dynamic control-flow transfers with related hooks in the kernel space. Experiments show that HooklMA is capable of detecting compomised kernel hooks caused by kernel rootkits. Performance evaluations with UnixBench indicate that runtirre overhead introduced by HooklMA is about 21.5%.
文摘A mathematical model is developed based on a simplified mechanism of anaerobic digestion. The main objective is to quantitatively analyze the digestion process to optimize operating conditions and maintenance of this equipment, which could be used to test different materials and be able to apply these results to the possible scaling to bio-digesters installed in the field. The experiments were carried out in a hybrid system bio-digester photovoltaic cells. The bio-digester is made of stainless steel with dimensions to treat an average of 10 kg of raw material and produce biogas from different organic materials. The reactor has been conditioned with temperature sensors, pressure and methane gas that allow monitoring the concentration of the gas and the conditions of operation during the time of digestion. The system has a photovoltaic array to provide the energy required to keep the temperature constant, The experiment was conducted using materials such as goat manure mixed with household waste, and various formulations of these materials were prepared. The experimental results were used to test the mathematical model.
