WoS İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8653
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Article Citation - WoS: 4Citation - Scopus: 5Diffraction of Electromagnetic Waves by a Planar Interface Between Perfectly Absorbing and Anomalously Transmitting Metasurface Half-Planes(Elsevier Gmbh, 2019) Umul, Yusuf ZiyaThe interaction process of electromagnetic waves by a planar interface between perfectly absorbing and anomalously refracting metasurface half-planes is investigated. First of all, the scattered geometric optics field is obtained from the difference of the total geometric optics and initial waves. The diffracted fields are determined by using a relation between the scattered geometric optics and diffraction waves at the transition boundaries. It consists of the diffraction fields of perfectly absorbing and anomalously refracting metasurface half-screens. The behaviors of the total, total geometric optics and diffracted waves are studied numerically.Article Citation - WoS: 1Citation - Scopus: 1Interaction of Electromagnetic Waves by a Cylindrical Parabolic Mesh Reflector(Elsevier Gmbh, 2019) Umul, Yusuf ZiyaA cylindrical parabolic reflector, composed of mesh grid, is modeled by a resistive surface. The analysis of the scattered waves is performed by the physical optics integral, which was developed for resistive surfaces. The integral is evaluated asymptotically for large values of the wave-number in high-frequencies. The geometrical optics and diffracted fields are obtained by the methods of stationary phase and edge point respectively. The uniform forms of the diffracted waves are derived. The total wave and its components are investigated numerically for different values of surface resistivity.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: 4Citation - Scopus: 4An Analytical Solution for the Plane Wave Diffraction by a Resistive Half-Plane Residing at the Interface of Left and Right Handed Media(Elsevier Gmbh, 2019) Basdemir, Husnu DenizThe diffraction of waves by a resistive half-plane lying on the interface of left and right handed media is investigated in this study. Because of the anomalous refraction property of left handed media, shadow boundary shifts toward to the lower surface of the half-plane. In order to obtain the shifted boundary, diffracted waves are divided to subfields. Thus, obtained diffracted waves compensates the deficiency of geometries optics fields at the transition regions. The uniform version of waves is obtained by using the uniform theory of diffraction. The wave behaviors are examined numerically.Article Citation - WoS: 5Citation - Scopus: 5Wave Diffraction by a Right-Angled Interface Between Resistive Half and Whole Planes(Elsevier Gmbh, Urban & Fischer verlag, 2018) Umul, Yusuf ZiyaThe interaction phenomenon of electromagnetic plane waves by a right angled interface between whole and half screens with different resistivities is studied. The construction, under examination, is considered in order to model various corner discontinuities between transmissive surfaces for indoor wireless communications. First of all, the initial waves, which occur in the absence of the diffracting edge, are determined. Then the scattered geometrical optics fields are obtained by subtracting the initial waves from the total geometrical optics fields. The diffracted field is constructed directly from the scattered geometrical optics wave by a new method. The resultant field expressions are examined numerically.Article Citation - WoS: 1Citation - Scopus: 1Wedge Diffraction Model in Gravitational Lensing by Cosmic Strings(Elsevier Gmbh, 2018) Umul, Yusuf ZiyaA cosmic string forms a conical topology, which enables a diffraction phenomenon by a wedge with an inner angle, equals to the double of the deficit angle. A wedge, on the edge of which the string is located, is defined in the flat space-time. The radiated wave from a star is represented by two plane waves, propagating on the two surfaces of the wedge for grazing incidence. The uniform expressions of the diffracted waves are obtained and investigated numerically. (C) 2017 Elsevier GmbH. All rights reserved.Article Citation - Scopus: 1Diffraction of Waves by a Conductive Half-Plane(Elsevier Gmbh, Urban & Fischer verlag, 2017) Umul, Yusuf ZiyaThe scattering process of plane waves by a conductive half-plane is investigated. The scattered geometrical optics waves are obtained by subtracting the incident field from the total geometrical optics waves. The physical optics integral is constructed from the scattered geometrical optics fields. The diffracted waves are evaluated by the application of the edge point method to the physical optics integral. A correction field is added to the diffracted waves in order to satisfy the conductive boundary conditions on the surfaces of the half plane. The uniform diffracted fields are evaluated and the resultant scattered waves are compared with the literature numerically. (C) 2016 Elsevier GmbH. All rights reserved.Article Wave Diffraction by a Metallic Half-Plane(Elsevier Gmbh, Urban & Fischer verlag, 2016) Umul, Yusuf ZiyaThe scattering problem of plane waves by a half-screen with different face impedance is obtained with a geometrical optics-physical optics based method. The kernel of the physical optics integral is redefined by using coefficients that guarantee the satisfaction of the boundary condition on the surface of the scatterer. The uniform diffraction fields are obtained and the behavior of the scattered waves is investigated numerically for different values of the surface impedance. (C) 2015 Elsevier GmbH. All rights reserved.Article Citation - WoS: 1Citation - Scopus: 1The Relation Between Wave Vector and Momentum in Quantum Mechanics(Elsevier Gmbh, 2016) Umul, Yusuf Z.The fundamental relation of quantum mechanics, which correlates the momentum of a quantum particle to the wave vector of the matter wave, is re-interpreted. The wave vector, in the relation, is formulized as the integration of it along the angular coordinates for two and three dimensional cases. Various evaluations of the wave vector are performed for different types of waves and the results are discussed. Also the edge diffracted fields are considered according to the new interpretation. (C) 2016 Elsevier GmbH. All rights reserved.Article Citation - WoS: 12Citation - Scopus: 12Scattering of Waves by a Perfectly Conducting Wedge Residing at the Interface Between Two Isorefractive Media(Ieee-inst Electrical Electronics Engineers inc, 2016) Basdemir, Husnu DenizScattered field by a wedge that is surrounded by isorefractive media is analyzed. A series-based method is introduced and applied to the wedge problem with soft boundary condition. The fields are examined numerically. The numerical results show that the proposed method is suitable for analysis of these kinds of problems.