Access control in open and dynamic Pervasive Computing Environments (PCEs) is a very complex mechanism and encompasses various new requirements. In fact, in such environments, context information should be used in access control decision process; however, it is not applicable to gather all context information completely and accurately all the time. Thus, a suitable access control model for PCEs...

In view of malicious insider attacks on cloud computing environments, a new ContextAware Access Control Model for cloud computing (CAACM) was presented. According to the characteristic of cloud computing, we take spatial state, temporal state and platform trust level as context. The model establishes mechanisms of authorization from cloud management role to objects, which enables dynamic activa...

This paper discusses the implementation of protecting user's data on mobile device based on Android platform. The mobile platform surpasses computers in its popularity in many aspects of one daily routine. Protection of data is one of the basic security feature of each operating system. Android platform raise its protection with every new version of the system. This paper covers the new approac...

reduced-activation ferritic/martensitic steels have been developed by replacing molybdenum by tungsten and niobium by tantalum in commercial elevated-temperature cr–mo steels to reduce half-life of radioactive isotopes. the objective of this study was to investigate tensile properties of a reduced-activation ferritic/martensitic steel (9cr-2wvta) in normalized-tempered (nt) and quenched-tempere...

Access control technology is one of the key technologies to ensure safe resource sharing. Identity authentication and authority distribution are two for access restrict unauthorized users from accessing resources, only authorised legal can resources. However, user privacy protection frequent permission changes thorny issues that need be solved urgently by technology. In this paper, a dynamic mo...

Dimerization process is essential for producing copolymers. The features of dimerization process like thermal-oxidative degradation should be well known to reach maximum efficiency and a superior reactor design. Also, the degradation mechanism of biodegradable polymers is important during sterilization processes. Thermal-oxidative degradation of PGA, PLLA, and their binary copolymers was invest...