Hierarchical access control policies, in which users and objects are associated with nodes in a hierarchy, can be enforced using cryptographic mechanisms. Protected data is encrypted and authorized users are given the appropriate keys. Lazy re-encryption techniques and temporal hierarchical access control policies require that multiple keys may be associated with a node in the hierarchy. In thi...

The data used by physicians in patient care is hypermedia in true sense of the word. We propose a Distributed Hypermedia Model(DHM) to logically integrate distributed, multimedia patient data, and provide friendly user interface to give authorized physicians transparent access to these data across the network. This article discusses the architecture of DHM, which can serve as a model for defini...

Conventional digital libraries utilize access control and digital watermarking techniques to protect their digital content. These methods, however, have drawbacks. First, after passing the identity authentication process, authorized users can easily redistribute the digital assets. Second, it is impractical to expect a digital watermarking scheme to prevent all kinds of attack. Thus, how to enf...

In this paper, we show our visualization approach for supporting interactive document retrieval based on authorized documents, such as survey articles or domain dictionaries. We assume that it is effective for accessing the required information sources that the system let users recognize the information space inclusively. Our research, therefore, aims to support users to access the information ...

This paper argues that there is significant benefit in providing multiple progressively stronger layers of security for hosts connecting to the Internet. It claims that this multi-layered approach allows early discard of packets associated with attacks. This reduces server vulnerability to computational denial-of-service attacks via heavyweight cryptography calculations. To this end, it present...

We performed small-angle neutron scattering and neutron spin echo experiments on a ternary microemulsion composed of ionic surfactant AOT, water, and decane. Thermal fluctuations of monolayers have been investigated as a function of temperature and pressure. The amphiphilic monolayers become more flexible with increasing temperature and more rigid with increasing pressure. These results are con...

The fluorescence characteristics of norfloxacin (NFLX) were studied in reversed micelles which formed with sodium bis(2-ethylhexyl) sulfosuccinate (AOT)-water-octane. The influences of the environmental factors, such as the water content, AOT concentration and pH, on the fluorescence of NFLX were investigated. A novel spectrofluorimetric method for the direct determination of NFLX is proposed b...

Databases hold a critical concentration of sensitive information and become available on the internet to facilitate access, and as a result, databases are vulnerable and become the target of hackers. Today the security of database system become one of the most urgent tasks in database research, so to protect database system from attacking and compromised through authorized users who abuse or mi...