Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8651
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Article Diffraction of Waves by a Wedge with Phase Conjugate Faces(Association for Scientific Research, 2011) Umul, Yusuf ZiyaArticle Citation - WoS: 8Citation - Scopus: 9Diffraction of Waves by an Impedance Half-Plane(Elsevier Science Bv, 2013) Umul, Y. Z.The solution of the diffraction problem of waves by an impedance half-plane that satisfies the impedance boundary condition is obtained for the first time in the literature. A reflection coefficient which is the function of the angular and spatial variables in the polar coordinates is defined and its exact expression is obtained with the aid of the impedance boundary condition. The resultant diffraction field is compared with the solution of Malyuzhinets numerically and their differences are stressed. The structures of the total scattered, geometrical optics and diffracted waves are also investigated. (C) 2013 Elsevier B.V. All rights reserved.Article Citation - WoS: 1Citation - Scopus: 1Three Dimensional Theory of the Boundary Diffraction Wave(Elsevier Gmbh, 2019) Umul, Yusuf ZiyaThe line integral of the boundary diffraction wave theory, which yields the diffracted fields by an edge discontinuity, is obtained from the surface integral of the modified theory of physical optics. The line integral is evaluated by using the edge point method. The generalization of the integral is performed for curved edges. In this case the kernel is a function of two variable angles.Article Citation - WoS: 5Citation - Scopus: 6Scattering of Waves by a Half-Screen Between Isorefractive Media(Elsevier Gmbh, 2018) Umul, Yusuf ZiyaThe scattering process of plane electromagnetic waves by a perfectly conducting half-plane, residing between isorefractive media, is investigated. The semi-infinite interface between two different media is modeled by using a resistive surface, since it causes the reflection and transmission of the incident wave. Thus the scenario is reduced to the diffraction problem of waves by the junction of two half-screens. The diffracted field is expressed with the aid of the split function that occurs in the Wiener-Hopf factorization of the scattered waves by imperfectly conducting half-planes. The total, geometrical optics and diffracted waves are analyzed numerically. (C) 2017 Elsevier GmbH. All rights reserved.Article Citation - WoS: 1Citation - Scopus: 2General Expression of the Diffracted Waves by a Half-Screen With Generalized Impedance Boundary Conditions(Elsevier Gmbh, Urban & Fischer verlag, 2019) Umul, Yusuf ZiyaThe diffraction process of plane waves by a half-screen with generalized impedance boundary conditions is studied. Firstly, the scattered geometrical optics waves are obtained by subtracting the incident field from the total geometrical optics wave. The diffracted field expressions are derived by taking into account the construction of the scattered geometrical optics wave for first, second and third order impedance half-planes. Then the diffracted field expression is generalized for the Nth order half-screen. The uniform representation of the edge diffracted wave is obtained by considering the exact solution of Sommerfeld. The behaviors of the total, total GO and diffracted fields are analyzed numerically.Article Citation - WoS: 1Citation - Scopus: 1Wave Diffraction by a Half-Screen With Nth Order Generalized Sheet Transition Conditions(Elsevier Gmbh, Urban & Fischer verlag, 2019) Umul, Yusuf ZiyaThe scattering of plane waves by a half-plane with Nth order transition conditions is investigated. First of all, the reflection and transmission conditions of the transmissive surface are evaluated by using the generalized sheet transmission boundary conditions. The scattered geometrical optics fields are determined from the total geometrical optics and incident waves. The diffracted field is obtained by using a relation between the scattered geometrical optics and diffracted waves. The behaviors of the total, total geometric optics and diffracted fields are analyzed numerically.Article Citation - WoS: 8Citation - Scopus: 8Scattering of Plane Waves by a Rational Half-Plane Between Dng Media(Elsevier Gmbh, 2019) Basdemir, Husnu DenizScattering of plane waves by a hard-soft half-plane which is lying between double negative material is investigated. The diffracted fields are determined by dividing the diffraction coefficient to four subfields for satisfying the boundary conditions. It is observed that the shadow boundary shifts towards to lower surface of the half-plane. Also geometric optics fields are determined by using the geometry of the problem. As a result, the behavior of the fields is investigated numerically.Article Citation - WoS: 14Citation - Scopus: 15Scattering of Electromagnetic Waves by a Perfect Electromagnetic Conductor Half-Screen(Elsevier Gmbh, 2019) Umul, Yusuf ZiyaThe diffraction of plane electromagnetic waves by a perfect electromagnetic conductor half screen is investigated. The total geometrical optics fields are obtained by using the boundary conditions of a perfect electromagnetic conductor surface. A general relation is defined for the scattered fields in terms of waves by soft and hard surfaces. The total scattered field is derived by using this relation. Some numerical simulations are also given.Article Citation - WoS: 4Citation - Scopus: 4Scattering by a Resistive Half-Plane Residing Between Two Dissimilar Media(Elsevier Gmbh, 2019) Umul, Yusuf ZiyaThe scattering problem of plane electromagnetic waves by a resistive half-plane, located at the planar interface of two media with different electromagnetic properties, is studied. First of all, the reflection and transmission coefficients of a resistive whole plane, between two different media, are evaluated. The scattered geometrical optics waves are obtained for the problem under consideration. They are used in order to determine the diffracted waves, which are expressed in terms of a split function that arises in the solution of the diffraction problem by a resistive half plane. The uniform diffraction fields are obtained by using the uniform theory of diffraction. The behavior of the total, total geometric optics and diffracted waves are studied numerically.Article Citation - WoS: 6Citation - Scopus: 7Diffraction by a Planar Junction Between Resistive and Perfect Electromagnetic Conductor Half-Screens(Elsevier Gmbh, 2019) Umul, Yusuf ZiyaThe interaction of plane electromagnetic waves by a planar junction between resistive and perfect electromagnetic conductor half-planes is investigated. First of all the initial waves for a whole resistive plane is evaluated. Then the scattered geometric optics fields are obtained from the difference of the total geometric optics and initial waves. The diffracted fields are evaluated with the aid of a relation between the scattered geometric optics and diffraction fields at the transition boundaries. It is found that the interaction between the two half-screens occur only for the z-polarized electric fields.