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By using the simple decoupling approximation to Fermi-type Green's function for the transverse Ising model under pseudospin theory, we systemically study the influence of different exchange interactions (transverse fields) of the two distinct materials on the polarization and Curie temperature of finite alternating superlattice. Meanwhile, we analyze the effect of the whole parameters of the top surface, present their influence on the polarization of each layer (including the mean polarization of the whole ferroelectric superlattice) and on the Curie temperature. The results show the ratio of the exchange interactions (the transverse fields), which are of the two alternating materials have deeply impact on the polarization and Curie temperature of the supperlattice. Moreover, the top surface also has great influence on the whole ferroelectric superlattice.

Based on the transverse Ising model and using decoupling approximation to the Fermi-type Green's function, we study the phase transition properties of the epitaxial ferroelectric film with one substrate. A general recursive equation of the ferroelectric thin film with two n-layer materials is obtained, which enables us to study the phase transition properties for any number layers for epitaxial ferroelectric thin film. With the help of this equation, we analyze the effect of the exchange interaction and the transverse field in the phase diagram, the influence to the polarizations and Curie temperature numerically. The results show that epitaxial ferroelectric film are able to induce a strong increase or decrease of Curie temperature to different exchange interactions and transverse fields within the epitaxial film layers. The theoretical results are in reasonable accordance with experimental data of different ferroelectric thin film.

MMS (Multimedia Messaging Service) index prediction plays an important role to the development of MMS business. Currently, MMS index prediction model based on back propagation (BP) neural network easily falls into local minimum because of the randomness of weights selection. So the genetic algorithm which is good at global search optimizes weights of BP neural network. Firstly, the genetic algorithm searches weights in the global scope and then BP algorithm further optimizes weights. Finally, the optimized algorithm achieves better prediction accuracy.

In this paper a new blind watermarking algorithm based on DCT (discrete cosine transform) and DWT (discrete wavelet transform) was proposed. In order to enhance the security of watermarking, Arnold transform is carried out on the watermark image. Firstly discrete wavelet transform is carried out on the host image three times. Secondly the low resolution sub-image of DWT (LL3) is divided in to 8*8 blocks and then discrete cosine transform is carried out on the blocks. At last the middle frequency coefficients of the blocks are selected to embed the watermark image. In term of traditional algorithm the experiment results show that the new algorithm keeps the quality of host image well and a high robustness against common attacks such as JPEG compression, additive Gaussian noise, image rotation, image cropping and so on.

Because of the virtue mobility, flexibility, and convenience, more and more wireless network are used in our everyday life. During the move between two scales of different AP (Access Point), the quality of the services heavily depends on the seamless handoff scheme which provide less packet lost. There are many people propose lots of strategies to reduce packet lost and do many contribution to it. In this paper, a dynamically adjusted buffer size algorithm and a predictable handoff tendency formula are used together. We use the two schemes to reduce packet lost. According to analysis the simulation result, we can conclude that the method we used in experiment reduce the packet lost when a MN (Mobile Node) move from one scale to another.

An intelligent home system is designed and implemented based on the context-awareness technology, which minimizes users’ interventions and maximizes functional autonomy of systems. A multi-agent technology is proposed based and service oriented approach to build our middleware which supports tasks including acquiring, discovering, interpreting, reasoning, accessing various contexts and interoperability between different context-aware systems. In order to simplify the design of our middleware and make it convenient for users, a third-party, “Internet service providers”, is proposed which is responsible for the service updating and service composition.

During the past decade, there have been many agent-based middleware architectures proposed for implementing agent-based middleware systems in various context aware application fields. But those systems are not based on the real intelligent agent. In this paper, we propose an intelligent agent-based middleware for context aware systems (IAMCAS). It aims to sense, combine, infer, predict and learn context information securely in order to provide users with various services in changing environments. We partially implemented the proposed framework for a Location-Aware Messages System as an application example.