WoS İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8653
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Article Citation - WoS: 11Citation - Scopus: 9Diffraction of Cylindrical Waves by a Perfectly Conducting Half-Screen: a Modified Theory of Physical Optics Solution(Wiley-blackwell, 2016) Umul, Yusuf Ziya; Ziya Umul, YusufThe scattering problem of waves, radiated by a line source, is investigated by the method of modified theory of physical optics. The solution is obtained for both of the Dirichlet and Neumann boundary conditions. Two dimensional modified theory of physical optics integral is considered, since the problem is symmetric according to one of the spatial coordinates. The scattering integral is directly evaluated and a new function is defined for the scattered fields. The mathematical properties of the function are studied. The total, geometrical optics and diffracted waves are analyzed numerically. (C) 2016 Wiley Periodicals, Inc. View this article online at wileyonlinelibrary.com.Article Citation - WoS: 7Citation - Scopus: 7Scattering Theory of Waves by a Perfectly Conducting Half-Screen Between Two Different Media(Wiley, 2015) Umul, Yusuf ZiyaThe scattering process of electromagnetic waves by a half-plane, located at the interface of two media with different dielectric constants, play an important role in the remote sensing applications and wireless technology for wave propagation over land-sea transition. In this article, the diffracted fields are obtained for such geometry with the aid of a physical optics-based method. A scattering integral is constructed for both of the media. The diffracted fields are obtained by the edge point technique and the constants, which were added to the diffraction coefficients, were evaluated from the continuity conditions across the transition of the two mediums. The uniform expressions of the diffracted waves are obtained and the results are investigated numerically. (c) 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1928-1933, 2015Article Citation - WoS: 2Citation - Scopus: 3Wedge Diffraction in Terms of the Method of Physical Optics(Ieice-inst Electronics information Communications Eng, 2009) Umul, Yusuf Z.The method of physical optics is extended for wedge diffraction. The classical integral of physical optics is taken into account for the diffraction problem of plane waves by a conducting half-plane. The integral is decomposed according to the transmitted and reflected scattered waves. The sinusoidal term in the integrand is rewritten by considering the fact that the half-plane is a special case of the wedge. Two cases of soft and hard surfaces are examined and the uniform diffracted waves are obtained by the asymptotic evaluation of the integrals. The results are compared with the literature numerically.Article Citation - WoS: 9Citation - Scopus: 9Uniform Version of the Modified Theory of Physical Optics Based Boundary Diffraction Wave Theory(Taylor & Francis Ltd, 2008) Umul, Yusuf Z.The potential function of the modified theory of physical optics based boundary diffraction wave theory is made uniform by using the principles of the uniform theory of diffraction. The line integration of this new function along the edge contour gives the uniform diffracted fields which are finite for the transition regions of the diffraction geometry. The method is applied to the diffraction problem by the edge of a curved surface.Article Citation - WoS: 7Citation - Scopus: 8The Theory of the Boundary Diffraction Wave for Wedge Diffraction(Taylor & Francis Ltd, 2008) Umul, Yusuf Z.A new potential function, line integration which gives the edge diffracted fields, is constructed for wedge diffraction by using the method of modified theory of physical optics. The surface integrals are transformed into line integrals by the technique of asymptotic reduction. As an application of the novel potential function, the diffracted field is obtained for the geometry of a wedge for arbitrary incidence of plane waves.