Elektronik ve Haberleşme Mühendisliği Bölümü Yayın Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/260
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Editorial Citation - WoS: 1Citation - Scopus: 1Reply To the "a Comment on "the Photon Momentum(Elsevier Gmbh, Urban & Fischer verlag, 2014) Umul, Yusuf Z.Correction Comment on "a Survey of the New Proposal About the Photon Momentum" (Vol 148, Pg 342, 2017)(Elsevier Gmbh, Urban & Fischer verlag, 2018) Umul, Yusuf Z.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: 2Citation - Scopus: 2Scattering of a Bessel Beam by a Resistive Disc(Elsevier Gmbh, Urban & Fischer verlag, 2017) Umul, Yusuf Z.Bessel beam has two important advantages that make it preferable for the illumination process of biological samples in microscopy. These are the properties of non-diffraction and self-healing. In this paper, the interaction of the zeroth order Bessel beam with a resistive disc, which models a cell or tissue, is investigated by using the uniform geometrical theory of diffraction. The geometrical optics and diffracted waves are evaluated. The scattering characteristics of the beam and the property of self-healing are studied numerically for different values of the surface resistivity. (C) 2016 Elsevier GmbH. All rights reserved.Article Wave Diffraction by Material Half-Planes(Elsevier Gmbh, Urban & Fischer verlag, 2017) Umul, Yusuf ZiyaThe diffraction of E-polarized electromagnetic waves by resistive and conductive half planes is studied. The solution of Maliuzhinets for the scattering problem of plane waves from an impedance half-screen is taken into account. The diffracted fields from the resistive and conductive half-planes are obtained by using a relation between the scattered waves from material surfaces. The integrals ofscattering are also constructed in the complex plane. The resultant field expressions are compared with the literature numerically. (C) 2016 Elsevier GmbH. All rights reserved.Article Citation - WoS: 10Citation - Scopus: 11Wave Diffraction by the Junction Between Resistive and Soft-Hard Half-Screens(Elsevier Gmbh, Urban & Fischer verlag, 2017) Umul, Yusuf ZiyaThe scattering process of planes waves by a junction between resistive and soft/hard half-planes is investigated. First of all, the initial and total geometrical optics fields are determined by considering the related geometries. The scattered geometrical optics wave is obtained by subtracting the initial field from the total geometrical optics wave. The diffracted fields are derived by taking into account the behaviour of the geometrical optics wave at the reflection and shadow boundaries. The uniform expressions of the diffracted waves are constructed with the aid of the uniform theory of diffraction. The total field expressions are examined numerically. (C) 2016 Elsevier GmbH. All rights reserved.Article Citation - WoS: 5Citation - Scopus: 5Exact Form of the Physical Optics Integral(Elsevier Gmbh, Urban & Fischer verlag, 2017) Umul, Yusuf ZiyaThe exact structure of the physical optics integral is obtained. With this aim, the rigorous solution of the diffraction problem of waves by a perfectly conducting half-plane is considered. The Fresnel integrals of the incident and reflected scattered fields are transformed into the physical optics integrals by defining a suitable variable transform. The relation of the obtained integral with the modified theory of physical optics is discussed. (C) 2016 Elsevier GmbH. All rights reserved.Article Citation - WoS: 6Citation - Scopus: 6Directive Line Source Scattering by a Half-Plane Between Two Isorefractive Media(Elsevier Gmbh, Urban & Fischer verlag, 2017) Basdemir, Husnu DenizA perfectly conducting half-plane which is lying at the interface between two isorefractive media is investigated for a directive line source illumination. For this purpose, a directive line source is defined by passing a plane-wave from an aperture. Also, more suitable function than the Fresnel function is defined for cylindrical sources. The scattered field and its subfields are obtained by a new method. Consequently, all the mentioned fields are analyzed numerically. (C) 2016 Elsevier GmbH. All rights reserved.Article Citation - WoS: 5Citation - Scopus: 5Diffraction of Electromagnetic Waves by a Wedge With Perfectly Absorbing and Impedance Faces(Elsevier Gmbh, Urban & Fischer verlag, 2018) Umul, Yusuf ZiyaThe scattering process of electromagnetic waves by a wedge with perfectly absorbing and impedance faces is investigated. The scattered geometric optics waves are obtained for two cases, namely the illumination of single and double faces. The geometric optic field is expressed as a sum of two fields, which represent two wedges with different boundary conditions. The diffracted waves are determined for both of the wedge configurations. The behaviours of the total, total geometric optics and diffracted fields are studied numerically.
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