Parabolic Equations 5 Partial differential equations 4 Threedimensional (3-d) 4 Acoustic wave propagation 3 Numerical methods 3 Acoustic fields 2 Nonlinear equations 2 Underwater acoustics 2 article 2 Acoustic Scattering 1 Acoustic propagation 1 Alternating directions 1 Ambient noise model 1 Atlantic islands 1 Barycentric lagrange interpolation 1 Benchmarking 1 Boundary conditions 1 Boundary interactions 1 Boundary-fitted grid 1 Broadband transmission 1 Circular waveguides 1 Columbia river estuaries 1 Comprehensive Nuclear-Test-Ban Treaty 1 Convergence 1 Cross spectral densities 1 Cryptography 1 Earthquakes 1 Elliptic equations 1 Encryption algorithms 1 Encryption methods 1