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We consider the development and analysis of local discontinuous Galerkin methods for fractional diffusion problems in one space dimension, characterized by having fractional derivatives, parameterized by β ∈ [1, 2]. After demonstrating that a classic approach fails to deliver optimal order of convergence, we introduce a modified local numerical flux which(More)
The pitch angle controller is designed for SCIG wind power system by using sliding mode control to level the output power of wind turbine generation (WTG) at the rated power. The WTG system model is established by using small signal method. Then the pitch angle control system is designed based on the sliding mode control via reaching law. At last, the(More)
Studies of nest-site selection and reproduction are essential for bird species assessment and conservation. We compared breeding habitats and random sites within a secondary cavity-nesting bird, Yellowrumped Flycatcher (Ficedula zanthopygia), in a 5-year studying period in northeast China. We also modeled the effects of factors on daily nest survival rates.(More)
The V-cycle multigrid method can significantly lower the computational cost, yet their uniform convergence properties have not been systematically examined, even for the classical parabolic partial differential equations. The main contribution of this paper is that by improving the framework of convergence estimates for multigrid method [Math. Comp., 49(More)
The traditional wave equation models wave propagation in an ideal conducting medium. For characterizing the wave propagation in inho-mogeneous media with frequency dependent power-law attenuation, the space-time fractional wave equation appears; further incorporating the additive white Gaussian noise coming from many natural sources leads to the stochastic(More)
The stability of a class of microgrid over wireless networks is considered in this paper. The microgird consists of a wind farm and main grid and it works in the grid-connected mode. The wireless network is inserted between the local controller and actuator of the wind turbine. The wireless network delays is characterized by a group of random numbers. The(More)
The nest-site selection and nesting success of Eurasian Nuthatch (Sitta europaea) were studied two habitats, suburb of Beijing and Zuojia Natural Reserve, in northeast China from 2004 to 2008. Nuthatches in the study area bred mostly in the deciduous stands. The frequency distribution of nest-cavity orientation was biased toward the southeast and the south.(More)
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