Wujun Zhang

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Machine Type Communication (MTC) and its related services have become the new business growth-point of mobile communication. However, application market with the size of about a hundred of million makes end-to-end security facing grand challenges, especially the repeated construction of authentication facilities for different applications. According to(More)
In cellular networks, Machine-Type Communication (MTC) has shown the advantages, including better coverage and lower network deployment cost, which makes it become the hotspot in industry area. However, the current cellular network is designed for human-to-human communication (H2H), and less optimal for machine-to-machine, machine-to-human or(More)
We consider the simplest one-constant model, put forward by J. Ericksen, for nematic liquid crystals with variable degree of orientation. The equilibrium state is described by a director field n and its degree of orientation s, where the pair (s, n) minimizes a sum of Frank-like energies and a double well potential. In particular, the Euler-Lagrange(More)
We design a two-scale finite element method (FEM) for linear elliptic PDEs in non-divergence form A(x) : D 2 u(x) = f (x). The fine scale is given by the meshsize h whereas the coarse scale is dictated by an integro-differential approximation of the PDE. We show that the FEM satisfies the discrete maximum principle (DMP) for any uniformly positive definite(More)
We propose a new a posteriori error analysis of the variable-degree, hybridized version of the Raviart-Thomas method for second-order elliptic problems on conforming meshes made of simplexes. We establish both the reliability and efficiency of the estimator for the L2-norm of the error of the flux. We also find the explicit dependence of the estimator on(More)