This paper describes an improved model for multiple building diffraction modeling based on the uniform theory of diffraction (UTD). A well-known problem in conventional uniform theory of diffraction (CUTD) is multiple-edge transition zone diffraction. Here, higher order diffracted fields are used in order to improve the result; hence, we use higher order diffraction coefficients to improve a hy...

Multiple-wave Diffraction Anomalous Fine Structure (MDAFS), a new method combining the X-ray multiple-wave diffraction with diffraction anomalous fine structure (DAFS) technique, provides the long-range order structure information by measuring the multiple-wave diffraction profiles in the vicinity of an absorption edge. The real part of dispersion correction and fine structure function can be o...

A formulation of the problem of scattering from obstacles with edges is presented. The formulation is based on decomposing the field into geometrical acoustics, first-order, and multiple-order edge diffraction components. An existing secondary-source model for edge diffraction from finite edges is extended to handle multiple diffraction of all orders. It is shown that the multiple-order diffrac...

in this paper the reflection coefficient of electromagnetic wave incidence on the walls of the buildings and obstacles that occurs in mobile communication path was modified by solving the riccati nonlinear equations. for this purpose, the building walls are assumed inhomogeneous layers where their permittivity changes as function of the wall thickness. using this reflection coefficient, a new p...

We consider the problem of multiple knife-edge diffraction estimation that is a fundamental task in many wireless communication applications. So far, one most accurate methods for this Vogler whose recursive implementation efficient to reduce high computational complexity direct one. However, original report, only presented final result algorithm without rigorous mathematical proof, thus making...

Accurate and efficient prediction of the sound field in shadow zones behind obstacles is a challenging task but essential to produce urban noise maps. A simplified method is presented to predict sound levels at shielded urban locations, including multi-edge diffraction over successive buildings and multiple reflections between parallel façades. The model is essentially based on Pierce's diffrac...

We present a fast algorithm to perform sound propagation in complex 3D scenes. Our approach computes propagation paths from each source to the listener by taking into account specular reflections and higher-order edge diffractions around finite edges in the scene. We use the well known Biot-Tolstoy-Medwin diffraction model along with efficient algorithms for region-based visibility to cull away...