A Modified T/2 Fractionally Spaced Coordinate Transformation Blind Equalization Algorithm

When T/2 Fractionally Spaced blind Equalization Algorithm based Constant Modulus Algorithm (T/2-FSE- CMA) is employed for equalizing higher order Quadrature Amplitude Modulation signals (QAM), it has disadvantages of low convergence speed and large Mean Square Error (MSE). For overcoming these disadvantages, a Modified T/2 Fractionally Spaced blind Equalization algorithm based on Coordinate Transformation and CMA (T/2-FSE-MCTCMA) was proposed by analyzing the character of 16QAM signal constellations. In the proposed algorithm, real and imaginary parts of input signal of T/2 fractionally spaced blind equalizer are equalized, respectively, and output signals of equalizer are transformed to the same unit circle by coordinate transformation method, a new error function is defined after making coordinate transformation and used to adjust weight vector of T/2 fractionally spaced blind equalizer. The proposed algorithm can overcome large misjudgments of T/2 fractionally spaced blind equalization algorithm for equalizing multi-modulus higher order QAM. Simulation results with underwater acoustic channel models demonstrate that the proposed T/2-FSE-MCTCMA algorithm outperforms T/2 Fractionally Spaced blind Equalization algorithm bas-ed on Coordinate Transformation and CMA (T/2-FSE-CTCMA) and the T/2-FSE-CMA in convergence rate and MSE.

Recent Results on Recurrent Solutions and Limit Distributions of SDEs

The limit distribution for homogeneous Markov processes is studied extensively and well understood,but it is not the case for inhomogeneous Markov processes.In this paper,we review some recent results on inhomogeneous Markov processes generated by non-autonomous stochastic(partial)differential equations(SDE in short).Under some suitable conditions,we show that the distribution of recurrent solutions of SDEs constitutes the limit distribution of the corresponding inhomogeneous Markov processes.

Poisson stable motions of monotone nonautonomous dynamical systems

In this paper, we study the Poisson stability(in particular, stationarity, periodicity, quasiperiodicity, Bohr almost periodicity, almost automorphy, recurrence in the sense of Birkhoff, Levitan almost periodicity, pseudo periodicity, almost recurrence in the sense of Bebutov, pseudo recurrence, Poisson stability) of motions for monotone nonautonomous dynamical systems and of solutions for some classes of monotone nonautonomous evolution equations(ODEs, FDEs and parabolic PDEs). As a byproduct, some of our results indicate that all the trajectories of monotone systems converge to the above mentioned Poisson stable trajectories under some suitable conditions, which is interesting in its own right for monotone dynamics.

Numerical study of the effects of Planetary Boundary Layer structure on the pollutant dispersion within built-up areas

The effects of different Planetary Boundary Layer（PBL） structures on pollutant dispersion processes within two idealized street canyon configurations and a realistic urban area were numerically examined by a Computational Fluid Dynamics（CFD） model. The boundary conditions of different PBL structures/conditions were provided by simulations of the Weather Researching and Forecasting model. The simulated results of the idealized 2D and 3D street canyon experiments showed that the increment of PBL instability favored the downward transport of momentum from the upper flow above the roof to the pedestrian level within the street canyon. As a result, the flow and turbulent fields within the street canyon under the more unstable PBL condition are stronger. Therefore, more pollutants within the street canyon would be removed by the stronger advection and turbulent diffusion processes under the unstable PBL condition. On the contrary, more pollutants would be concentrated in the street canyon under the stable PBL condition. In addition, the simulations of the realistic building cluster experiments showed that the density of buildings was a crucial factor determining the dynamic effects of the PBL structure on the flow patterns. The momentum field within a denser building configuration was mostly transported from the upper flow, and was more sensitive to the PBL structures than that of the sparser building configuration. Finally, it was recommended to use the Mellor-Yamada-Nakanishi-Niino（MYNN） PBL scheme, which can explicitly output the needed turbulent variables, to provide the boundary conditions to the CFD simulation.

Numerical Investigation and Uncertainty Analysis of Eastern China's Large-Scale Urbanization Effect on Regional Climate

Eastern China has experienced rapid urbanization during the past four decades,and it is necessary to understand the impacts of the urbanization on the regional climate.Previous simulations with either regional climate models(RCMs)or general circulation models have produced inconsistent and statistically non-significant urbanization effects on precipitation during the East Asian summer monsoon.In the studies with RCMs,reanalysis data were used as the lateral boundary conditions(LBCs)for both urban and non-urban experiments.Since the same LBCs may limit the urbanization effect,in this study,the Weather Research and Forecasting(WRF)model nested within the Global Forecast System(GFS),both of which were coupled with an urban canopy model,were used to explore the urbanization effect over eastern China.The WRF’s LBCs in the runs with/without urbanization were provided by the corresponding GFS runs with/without urbanization.The results showed a significant decrease in precipitation over North China,mainly due to a marked decrease in evaporation and the divergence induced by the reduced latent heating in the mid and upper atmosphere,from the experiment with urbanization.Meanwhile,to the north and south of the large-scale urbanization areas,especially to the south of the Yangtze River,precipitation increased significantly due to largescale urbanization-induced circulation change.With the same LBCs for the WRF runs with/without urbanization,the urbanization effects were limited only to urban and nearby areas;no significant change was found to the south of the Yangtze River,since the same LBCs hampered the effects of urbanization on large-scale circulation.In addition,this study demonstrated that the urban fraction may be a key factor that affects the intensity of the urbanization effect within the urban areas.