In high-speed railway (HSR) communication systems, distributed antenna is usually employed to support frequent handover and enhance the signal to noise ratio to user equipments. In this case, dynamic time-domain power allocation and antenna selection (PAWAS) could be jointly optimized to improve the system performances. This paper consider this problem in such a simple way where dynamic switchi...

Enforcing sparse structure within learning has led to significant advances in the field of data-driven discovery dynamical systems. However, such methods require access not only timeseries state system, but also time derivative. In many applications, data are available form time-averages as moments and autocorrelation functions. We propose a methodology discover vector fields defining (possibly...

We have developed a fast algorithm for computing certain entries of the inverse of a sparse matrix. Such computations are critical to many applications, such as the calculation of nonequilibrium Green’s functions G and G for nano-devices. The FIND (Fast Inverse using Nested Dissection) algorithm is optimal in the big-O sense. However, in practice, FIND suffers from two problems due to the width...

Dynamic imaging provides an effective way to integrate previous time-lapse data with current data in order to estimate a current model. We present two methods useful for continuous dynamic reservoir and subsurface monitoring. The first method is a stochastic method for the inversion of geophysical data. It uses the ensemble Kalman filter (EnKF) that we demonstrate using time-lapse surface seism...

The estimation of crustal structure and thickness is essential in understanding the formation evolution terrestrial planets. Initial planetary missions with seismic instrumentation on board face additional challenge dealing activity levels that are only poorly constrained a priori. For example, lack plate tectonics Mars leads to low seismicity, which could, turn, hinder application many data an...

Electrostatic correlations and fluctuations in ionic systems can be described within an extended Poisson-Boltzmann theory using a Gaussian variational form. The resulting equations are challenging to solve because they require the solution of a non-linear partial differential equation for the pair correlation function. This has limited existing studies to simple approximations or to one-dimensi...

Based on unmixing model and using the Thematic Mapper (TM) image as well as obtaining end-members by ground spectral measurements, quantitative retrieval of information on sparse vegetation coverage in oasis-desert transitional area in Minqin, Gansu was done. The results showed that a wide band of TM images can be used in extracting sparse vegetation coverage of arid regions. Three components w...