A Matlab toolbox for modelling viscoelastic constitutive equation and parameter optimization
A matlab toolbox for modelling viscoelastic constitutive equation has been implemented. It can be used to analysis the rheology properties of various viscoelastic constitutive equations by solving a time dependent PDE. The toolbox also provides support to calculate the optimized parameter of parameters to give a fine approximation with experiment data. We carefully designed the framework to make sure its extensibility and efficiency. Matlab parallel technology has been add to make the toolbox more computational efficient. The tool box does well on the rheology analysis of Rolie-Poly model and parameter optimization. This toolbox is significant to the study of viscoelastic models and provide a template for relative research areas.
We calculate the form factors and the coupling constant in the $D^{*}D \rho $ vertex in the framework of QCD sum rules. We evaluate the three point correlation functions of the vertex considering both $ D $ and $ \rho $ mesons off--shell. The form factors obtained are very different but give the same coupling constant: $g_{D^{*}D \rho} = 4.1 \pm 0.1$ GeV$^{-1}$.