This paper fist gives an investigation on trusted computing on mainstream operation system （OS）. Based on the observations, it is pointed out that Trusted Computing cannot be achieved due to the lack of separation m...This paper fist gives an investigation on trusted computing on mainstream operation system （OS）. Based on the observations, it is pointed out that Trusted Computing cannot be achieved due to the lack of separation mechanism of the components in mainstream OS. In order to provide a kind of separation mechanism, this paper proposes a separated domain-based kernel model （SDBKM）, and this model is verified by non-interference theory. By monitoring and simplifying the trust dependence between domains, this model can solve problems in trust measurement such as deny of service （DoS） attack, Host security, and reduce the overhead of measurement.展开更多
With analysis of limitations Trusted Computing Group （TCG） has encountered, we argued that virtual machine monitor （VMM） is the appropriate architecture for implementing TCG specification. Putting together the VMM...With analysis of limitations Trusted Computing Group （TCG） has encountered, we argued that virtual machine monitor （VMM） is the appropriate architecture for implementing TCG specification. Putting together the VMM architecture, TCG hardware and application-oriented ＂thin＂ virtual machine （VM）, Trusted VMM-based security architecture is present in this paper with the character of reduced and distributed trusted computing base （TCB）. It provides isolation and integrity guarantees based on which general security requirements can be satisfied.展开更多
Abstract Separation kernels are fundamental software of safety and security-critical systems, which provide their hosted applications with spatial and temporal separation as well as controlled information flows among ...Abstract Separation kernels are fundamental software of safety and security-critical systems, which provide their hosted applications with spatial and temporal separation as well as controlled information flows among partitions. The application of separation kernels in critical domain demands the correctness of the kernel by formal verification. To the best of our knowledge, there is no survey paper on this topic. This paper presents an overview of formal specification and verification of separation kernels. We first present the back- ground including the concept of separation kernel and the comparisons among different kernels. Then, we survey the state of the art on this topic since 2000. Finally, we summa- rize research work by detailed comparison and discussion.展开更多
Separation of shelled walnut particles was studied on two varieties of Persian walnut,Poost-Kaghazi and Poost-Sangi using pneumatic method.The moisture contents of the samples were determined.The particles were consid...Separation of shelled walnut particles was studied on two varieties of Persian walnut,Poost-Kaghazi and Poost-Sangi using pneumatic method.The moisture contents of the samples were determined.The particles were considered in three categories of shell,kernel and shell-kernel together.Each category was manually classified based on their size,in three portions of 1/8,1/4,and 1/2,as well as the whole kernel and whole walnut.The terminal velocity of each group was determined.The shelled walnuts were sieved and classified in three groups of small,medium and large.The effects of separation time(5,10 and 15 seconds),feeding value(50 to 80 gr)and air velocity on separation of the kernels and shells were studied for both varieties.The interaction effects were also studied for three walnut sizes(small,medium and large).The terminal velocity was the highest for the whole walnut and the whole kernel while it was lowest for 1/4 and 1/8 of the shell.The best separation was performed at air velocities of 9.20,10.04 and 10.94 m/s with 98.2%,98.9%and 98.2%,respectively.展开更多
基金Supported bythe National Basic Research Programof China (G1999035801)
文摘This paper fist gives an investigation on trusted computing on mainstream operation system （OS）. Based on the observations, it is pointed out that Trusted Computing cannot be achieved due to the lack of separation mechanism of the components in mainstream OS. In order to provide a kind of separation mechanism, this paper proposes a separated domain-based kernel model （SDBKM）, and this model is verified by non-interference theory. By monitoring and simplifying the trust dependence between domains, this model can solve problems in trust measurement such as deny of service （DoS） attack, Host security, and reduce the overhead of measurement.
基金Supported by the National Program on Key Basic Re-search Project of China (G1999035801)
文摘With analysis of limitations Trusted Computing Group （TCG） has encountered, we argued that virtual machine monitor （VMM） is the appropriate architecture for implementing TCG specification. Putting together the VMM architecture, TCG hardware and application-oriented ＂thin＂ virtual machine （VM）, Trusted VMM-based security architecture is present in this paper with the character of reduced and distributed trusted computing base （TCB）. It provides isolation and integrity guarantees based on which general security requirements can be satisfied.
文摘Abstract Separation kernels are fundamental software of safety and security-critical systems, which provide their hosted applications with spatial and temporal separation as well as controlled information flows among partitions. The application of separation kernels in critical domain demands the correctness of the kernel by formal verification. To the best of our knowledge, there is no survey paper on this topic. This paper presents an overview of formal specification and verification of separation kernels. We first present the back- ground including the concept of separation kernel and the comparisons among different kernels. Then, we survey the state of the art on this topic since 2000. Finally, we summa- rize research work by detailed comparison and discussion.
文摘Separation of shelled walnut particles was studied on two varieties of Persian walnut,Poost-Kaghazi and Poost-Sangi using pneumatic method.The moisture contents of the samples were determined.The particles were considered in three categories of shell,kernel and shell-kernel together.Each category was manually classified based on their size,in three portions of 1/8,1/4,and 1/2,as well as the whole kernel and whole walnut.The terminal velocity of each group was determined.The shelled walnuts were sieved and classified in three groups of small,medium and large.The effects of separation time(5,10 and 15 seconds),feeding value(50 to 80 gr)and air velocity on separation of the kernels and shells were studied for both varieties.The interaction effects were also studied for three walnut sizes(small,medium and large).The terminal velocity was the highest for the whole walnut and the whole kernel while it was lowest for 1/4 and 1/8 of the shell.The best separation was performed at air velocities of 9.20,10.04 and 10.94 m/s with 98.2%,98.9%and 98.2%,respectively.
