Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8651
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Book Review Citation - WoS: 4Citation - Scopus: 5The Theory of the Boundary Diffraction Wave(Elsevier Academic Press inc, 2011) Umul, Yusuf ZiyaArticle 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 - Scopus: 1Relativistic Wave Equation for a Quantum Particle With Potential Energy(Elsevier Gmbh, 2019) Umul, Yusuf ZiyaA new relativistic wave equation is derived for a quantum particle which moves in a potential. The relativistic equation of energy is reconsidered with the potential energy term. The energy-momentum relation is obtained for this case. The related differential equation is derived by taking into account a wave function in terms of a plane wave. It is shown that the new equation directly reduces to the Schrodinger equation of a particle, moving in a potential in the non-relativistic limit. The wave equation is applied to the interaction of wave function with a potential barrier.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 A New Approach To the Dirac Equation(Elsevier Gmbh, 2019) Umul, Yusuf ZiyaDirac equation is based on a novel method that expresses the roots of a square-root operation in terms of matrices. Instead of this technique we propose an alternative approach. The square-root expression is represented as a hypotenuse and it is written in terms of a trigonometric summation of the remaining two edges of a right-angle triangle. Both of the positive and negative energy terms are taken into account and a new matrix equation is obtained. The plane wave solutions of the new differential equation are studied.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.