Aizhen Liu

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In this paper an approach of using contextual information for structuring and displaying menus on small devices will be discussed, based on the implementation of a game for mobile games. CitizenMOB is a location-based, multiplayer, never-ending society-driven strategic mobile game that has been developed in order to understand today's possibilities and(More)
This paper proposes a new type of multi-user digital watermarking based on CDMA, which aims at the demand of multi-user copyright sharing protection. It presents two CDMA based approaches, i.e. wavelet domain direct approach (WD) and wavelet domain neighbor linear prediction approach (WNLP). It analyses the influence of user quantity and embedding depth on(More)
Mobile agent is an ideal programming diagram to construct open and dynamic application systems. But it still requires a great deal of maturity in security before being successful. Trust management is another way to enhance system security performance, but it has not been enough explored in mobile agent system. This paper first introduce the human trust(More)
By analyzing the causes of security problems in mobile agent systems and taking off the restriction of "absolute security", an idea of "enough security" with respect to the practical applications is proposed and a security frame model to protect both the mobile agent and the host is given. Meanwhile, a solution to evaluate the security properties in the(More)
0/1 knapsack problem belongs to combination optimization problem. Its optimal solution exists in the problem space including substantially large useless solutions besides optimal solutions. Differing with other SA (simulated annealing) algorithms that getting the approximate optimization solution from the whole problem space often need much computation(More)
This paper study the effect of cornea shape on optical imaging of the human eyes for future constructing a human eye model using ray tracing method in optical design software Zemax. Theoretical calculation results show that geometric image is best when the cornea's front surface radius being 7.8mm and gets bad away from 7.8mm. When the cornea's front(More)
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