Characterisation of space debris has become a fundamental task to facilitate sustainable operations. Ground-based surveillance provides the means extract key attributes from spacecraft. However, signal inversion attempts are generally under-constrained, which is why an increase in measurement channels through multispectral observations expected benefit parameter estimation. The current approach...

Direct numerical simulation (DNS) is the most accurate method of solving turbulence in fluids. In DNS the Navier-Stokes equations are solved on a fine mesh to resolve all the spatial and temporal scales present in the flow. In order to ensure high accuracy of the discrete solution, schemes with low numerical errors are necessary. Spectral methods with their low dissipation and dispersion errors...

Spectral element methods have previously been successfully applied to direct numerical simulation of turbulent flows with moderate geometrical complexity and low to moderate Reynolds numbers. A natural extension of application is to large eddy simulation of turbulent flows, although there has been little published work in this area. One of the obstacles to such application is the ability to dea...

LTE-Advanced (LTE-A) proposed by the 3rd Generation Partnership Project (3GPP) has successfully applied to the International Telecommunication Union (ITU) in 2010 to be accepted as an IMT-Advanced (IMT-A) compliant 4G mobile radio system. As part of this application 3GPP has provided LTE-A system level simulation results for cell spectral efficiency and cell edge user spectral efficiency. The I...

To improve spectral efficiency, a Hybrid modulation format based on combining of AM and UNB is proposed in the article. And channel capacity of the Hybrid modulation is analyzed. According to FCC AM spectral emission mask and china national standards on AM transmitter, the time and frequency domain characteristics of the modulation format are analyzed, it is fund that the licensed AM users can ...