Analytical expressions 1 Approximate analytical 1 Closed-form time-domain Green's functions 1 Distribution functions 1 Forestry 1 Fractional partial differential equations 1 Fractional wave equation Numerical methods 1 Probability densities 1 Time domain analysis 1 Time-domain Green's function 1 Ultrasound parameters 1 Wave equations 1 article 1 breast 1 calculation 1 liver 1 probability 1 ultrasound 1