المؤلفون: Tabakcıoğlu, Mehmet Barış, Cansız, Ahmet

مصطلحات موضوعية: Elektromanyetik dalga yayılımı, Eğim kırınımı, Düzgün kırınım teorisi, Çoklu kırınım, Electromagnetic wave propagation, Slope diffraction, Uniform theory of diffraction, Multiple-diffraction

الوصف: Dijital yayın sistemlerinde daha güvenilir yayın yapmak için kapsama alanı ve alıcı üzerindeki alan şiddetinin kestiriminde yayılım modelleri kullanılmaktadır. Yayılım modelleri temelde nümerik ve ışın izleme tekniğine dayanan modeller olmak üzere iki ana grupta incelenebilir. Elektromanyetik dalga yayılım modellerinde hesaplama zamanı ve kestirilen alan şiddetinin kesinliği arasında bir ödünleşme vardır. Nümerik modeller kesin sonuçlar vermesine karşın, hesaplama zamanı yüksektir, ışın izleme tekniğine dayanan modeller ise kesinliği az olmakla beraber hesaplama zamanı düşüktür. Hesaplama zamanı ve kesinlik açısından optimum olan modellere ihtiyaç duyulmuştur. Bunun için birçok model geliştirilmiştir. ; Electromagnetic wave propagation models have been used for coverage estimation and field prediction at the receiver to make more reliable and efficient digital broadcasting systems. Propagation models can be classified into two groups as numerical and ray tracing based models. There is a tradeoff between computation time and accuracy of field prediction among electromagnetic wave propagation models. Although numerical models predict accurately, it requires more computation times. Ray tracing based models predicts the field strength less accurately with lower computation time. Many propagation models have been developed to provide optimum solution for accuracy and computation time.

وصف الملف: application/pdf

العلاقة: Makale - Uluslararası Hakemli Dergi; Uludağ Üniversitesi Mühendislik Dergisi / Uludağ University Journal of The Faculty of Engineering; Tabakcıoğlu, M. B. ve Cansız, A. (2014). "Çoklu kırınımlar içeren senaryolar için elektromanyetik dalga yayılım modelleri". Uludağ Üniversitesi Mühendislik-Mimarlık Fakültesi Dergisi, 19(1), 37-46.; https://dergipark.org.tr/tr/download/article-file/202619Test; http://hdl.handle.net/11452/12061Test; 37; 46; 19

الإتاحة: http://hdl.handle.net/11452/12061Test
https://dergipark.org.tr/tr/download/article-file/202619Test

المؤلفون: Mehdi, Fikret

المساهمون: Doğangün, Adem, Bursa Uludağ Üniversitesi/Fen Bilimleri Enstitüsü/İnşaat Mühendisliği Anabilim Dalı., orcid:0000-0002-9373-9589

مصطلحات موضوعية: Dalga yayılımı, Deprem düşey bileşeni, Ölçeklendirme faktörü, Yüksek yapılar, Sayısal modelleme, Açık ve kapalı çözüm, Rayleigh sönümü, Wave propagation, High rise buildings, Numerical modeling, Explicit analysis, Rayleigh damping, Vertical ground motion, Scaling factor, Response spectrum, ASCE7-16, Eurocode 8

الوصف: Bu tez, yüksek binalarda dalga yayılma olgusunun temel fiziğinin sayısal yorumlanması üzerinedir. Tezin başlıca amacı, dalga yayılımının yüksek binaların sismik dinamik tepkisi üzerindeki etkilerini sayısal modeller geliştirerek irdelemektir. Çalışmayı gerçekleştirebilmek için iki ana unsur vardır: Birincisi dalganın seçimi ve ölçeklendirilmesi, ikincisi ise dalganın yayılacağı yapının modellenmesidir. Tez kapsamında esas olarak dikkate alınan dalga sismik bir dalgadır. Deprem yer hareketinin ölçeklendirilmesinde, depremin yatay bileşeni düşey bileşenine göre daha kapsamlı bir şekilde çalışılmıştır. Bu nedenle tezde, sismik yer hareketinin düşey bileşeninin ölçeklendirilmesine yoğunlaşılmış ve bunun için bir denklem önerilmiştir. Önerilen denklem, doğrusal olmayan bir regresyon analizinin sonucunda elde edilmiştir. Dalganın yayılacağı yapılar için idealleştirilmiş ve uygulamadaki taşıyıcı sistemleri temsil eden yüksek bina modelleri seçilmiştir. Gerçekleştirilen çalışmada, 300 m yüksekliğinde temsili sürekli bir mega kolondan ve ayrık perde duvardan oluştuğu kabul edilen iki yüksek yapı dikkate alınmıştır. Bu yapıların tabanına; enine ve boyuna doğrultularda dalga benzeri bir yarım sinüs darbesi şeklindeki dalga uygulanmıştır. Bu yapı modelleri üzerinde dalga yayılımını fiziki olarak görselleştirmek için, uygulamada doğrusal ve doğrusal olmayan analiz yapabilen yazılımların etkinliği araştırılmıştır. Daha sonra, çekirdek perde duvar ve çerçeve taşıyıcı sisteme sahip 46 katlı yüksek bina dikkate alınmıştır. Bu binanın tabanına enine ve boyuna doğrultularda sismik dalgalar uygulanmıştır. Binanın tabanından tepisine kadar dalgaların yayılımı, çekirdek perde duvar üzerinde ve çerçeve sistem üzerinde ayrı ayrı irdelenmektedir. Dikkate alınan yüksek bina taşıyıcı elemanlarındaki kesit etkileri (eksenel kuvvet, kesme kuvveti, eğilme momenti) ve göreli kat ötelenmesi dalga yayılımının dikkate alındığı ve ihmal edildiği durumlar için ayrı ayrı belirlenmiştir. Yapılan çalışmaları başlıca üç ana gurupta toplamak mümkündür. ...

وصف الملف: X, 121 sayfa; application/pdf

العلاقة: Tez; Mehdi, F. (2021). Dalga yayılımının yüksek binaların sismik davranışına olan etkilerinin sayısal olarak incelenmesi. Yayınlanmamış doktora tezi. Bursa Uludağ Üniversitesi Fen Bilimleri Enstitüsü.; http://hdl.handle.net/11452/20534Test

الإتاحة: http://hdl.handle.net/11452/20534Test

المساهمون: Bursa Uludağ Üniversitesi/Mühendislik Fakültesi/İnşaat Mühendisliği., orcid:0000-0003-2231-170X, orcid:0000-0003-1730-7810, Uzun, Büşra, Kafkas, Uğur, Yaylı, Mustafa Özgür, ABE-6914-2020, 57208629064, 57194631528, 44661926700

مصطلحات موضوعية: Axial spring, Bishop's rod theory, Frequencies, Nonlocal elasticity theory, Vibrational behavior, Free-vibration analysis, Nonlocal elasticity, Longitudinal vibrations, Wave-propagation, Deformation, Nonuniform, Nanobeams, Models, Mathematics, Mechanics, Elasticity, Linear transformations, Mathematical transformations, Nanorods, Arbitrary boundary conditions, Axial vibrations, Different boundary condition, Eigen-value problems, Non-local elasticity theories, System of linear equations, Vibrational modes, Boundary conditions, applied, Strain Gradient, Nonlocal

الوصف: In the present work, axial vibrational behavior of nanorods with different boundary conditions is researched. Bishop's rod theory is implemented to simulate the axial deflection. Size-dependency is captured by using Eringen's nonlocal elasticity theory. Based on nonlocal deformable boundary conditions and Stokes' transformation, a system of linear equations is derived and then constructed an Eigen value problem. Several numerical examples are presented to investigate the significance of various parameters such as geometric parameters, vibrational modes, various values of nonlocal parameter and axial spring parameters on the axial frequencies of nanorods. The numerical examples indicate that the deformable boundary conditions and small scale parameter have considerable effects on the axial vibration response.

العلاقة: Makale - Uluslararası Hakemli Dergi; ZAMM Zeitschrift fur Angewandte Mathematik und Mechanik; Uzun, B. vd. (2020). "Axial dynamic analysis of a Bishop nanorod with arbitrary boundary conditions". ZAMM Zeitschrift fur Angewandte Mathematik und Mechanik, 100(12).; https://doi.org/10.1002/zamm.202000039Test; https://hdl.handle.net/11452/39825Test; 000551849400001; 2-s2.0-85088378792; 100; 12

الإتاحة: https://doi.org/10.1002/zamm.202000039Test
https://hdl.handle.net/11452/39825Test

المساهمون: Uludağ Üniversitesi/Mühendislik Fakültesi/Elektronik Mühendisliği Bölümü., orcid:0000-0002-2740-8183, Karpat, Esin, AAH-3387-2021, 26428191600

مصطلحات موضوعية: Engineering, Telecommunications, Ground-penetrating radar, Breast-cancer detection, Inverse scattering, Metallic cylinder, Virtual tool, Fdtd, Simulation, Reconstruction, Algorithms, Finite difference time domain method, Clean technique, Finite difference time domains, Image domain, Imaging algorithm, Non destructive, Sar images, Scattering centers, Scattering data, Sub-surface imaging, Synthetic aperture radar, electrical & electronic, Parabolic Equation, Loran C, Ground Wave Propagation

الوصف: An image domain CLEAN technique, for nondestructive and noncontacting subsurface imaging, is discussed. Recently introduced finite-difference time-domain- (FDTD-) based virtual tool, GrGPR, is used to create imaging scenarios and to generate synthetic scattering data through synthetic aperture (SAR) type scanning. Matlab-based imaging algorithms are used to process recorded FDTD data. The location and the geometry of the targets are obtained by image domain CLEAN technique which is extracting scattering centers from the SAR image. The effectiveness of the algorithm is tested in simulated data.

وصف الملف: application/pdf

العلاقة: Makale - Uluslararası Hakemli Dergi; International Journal of Antennas and Propagation; Karpat, E. (2012). "CLEAN technique to classify and detect objects in subsurface imaging". International Journal of Antennas and Propagation, 2012, 1-6.; https://doi.org/10.1155/2012/917248Test; https://www.hindawi.com/journals/ijap/2012/917248Test/; http://hdl.handle.net/11452/25894Test; 000312808700001; 2-s2.0-84872161613; 2012

الإتاحة: https://doi.org/10.1155/2012/917248Test
http://hdl.handle.net/11452/25894Test
https://www.hindawi.com/journals/ijap/2012/917248Test/

المساهمون: Uludağ Üniversitesi/Mühendislik Fakültesi/Elektronik Mühendisliği Bölümü., orcid:0000-0002-2740-8183, Karpat, Esin, AAH-3387-2021, 26428191600

مصطلحات موضوعية: Engineering, Telecommunications, Ground-penetrating radar, Breast-cancer detection, Inverse scattering, Metallic cylinder, Virtual tool, Fdtd, Simulation, Reconstruction, Algorithms, Finite difference time domain method, Clean technique, Finite difference time domains, Image domain, Imaging algorithm, Non destructive, Sar images, Scattering centers, Scattering data, Sub-surface imaging, Synthetic aperture radar, electrical & electronic, Parabolic Equation, Loran C, Ground Wave Propagation

الوصف: An image domain CLEAN technique, for nondestructive and noncontacting subsurface imaging, is discussed. Recently introduced finite-difference time-domain- (FDTD-) based virtual tool, GrGPR, is used to create imaging scenarios and to generate synthetic scattering data through synthetic aperture (SAR) type scanning. Matlab-based imaging algorithms are used to process recorded FDTD data. The location and the geometry of the targets are obtained by image domain CLEAN technique which is extracting scattering centers from the SAR image. The effectiveness of the algorithm is tested in simulated data.

وصف الملف: application/pdf

العلاقة: Makale - Uluslararası Hakemli Dergi; International Journal of Antennas and Propagation; Karpat, E. (2012). "CLEAN technique to classify and detect objects in subsurface imaging". International Journal of Antennas and Propagation, 2012, 1-6.; https://doi.org/10.1155/2012/917248Test; https://www.hindawi.com/journals/ijap/2012/917248Test/; http://hdl.handle.net/11452/25894Test; 000312808700001; 2-s2.0-84872161613; 2012

الإتاحة: https://doi.org/10.1155/2012/917248Test
http://hdl.handle.net/11452/25894Test
https://www.hindawi.com/journals/ijap/2012/917248Test/

المساهمون: Uludağ Üniversitesi/Mühendislik Fakültesi/Elektrik ve Elektronik Mühendisliği Bölümü., Yalçın, Uǧur, AAG-8951-2021, 16023664100

مصطلحات موضوعية: Optics, Uniform asymptotic theory, Maggi-rubinowicz theory, Half-plane problem, Wedge, Physical optics, Wave propagation, Boundary diffraction waves, Diffraction problem, Impedance half-plane, Impedance surface, Modified theory of physical optics, Numerical results, Surface impedances, Vector potential, Diffraction, Half-Plane, Wave Diffraction

الوصف: Uniform diffracted fields from impedance surfaces are investigated by the extended theory of boundary diffraction wave (ETBDW). The new vector potential of the ETBDW is constructed by considering the pseudoimpedance boundary condition. The method is applied to the diffraction problem from an impedance half-plane. It is shown that the total fields from an impedance half-plane reduce to the case of a perfectly electric or magnetic conducting and opaque half-plane for special values of surface impedance. The total and diffracted fields are compared numerically with the exact solution for the impedance half-plane and modified theory of physical optics (MTPO) solution for an impedance wedge. The numerical results show that the field expressions are in very good agreement with the exact and MTPO solutions.

العلاقة: Makale - Uluslararası Hakemli Dergi; Applied Optics; Yalçın, U. vd. (2011). "Analysis of diffracted fields with the extended theory of the boundary diffraction wave for impedance surfaces". Applied Optics, 50(3), 296-302.; https://doi.org/10.1364/AO.50.000296Test; https://opg.optica.org/ao/abstract.cfm?uri=ao-50-3-296Test; http://hdl.handle.net/11452/25380Test; 000286507600010; 2-s2.0-78751615252; 296; 302; 50

الإتاحة: https://doi.org/10.1364/AO.50.000296Test
http://hdl.handle.net/11452/25380Test
https://opg.optica.org/ao/abstract.cfm?uri=ao-50-3-296Test

المؤلفون: Polat, Burak

المساهمون: Uludağ Üniversitesi/Mühendislik Fakültesi/Elektrik ve Elektronik Mühendisliği Bölümü., Zor, Ömer, 36976857500

مصطلحات موضوعية: Engineering, Telecommunications, Electromagnetic scattering, Method of moments, Sommerfeld problem, Thin wires, Vertical electric-dipole, Radio-wave propagation, Electromagnetic-field, Inhomogeneous earth, Conducting bodies, Dielectric layer, Grid model, Half-space, Radiation, Surface, Dielectric materials, Electromagnetic wave scattering, Spheres, Verification, Commercial software, Current distribution, Electrical field, Far field, Green function, Half spaces, High contrast, Impedance matrices, Impedance surface, Lossy dielectrics

الوصف: We investigate electromagnetic scattering from metallic thin wire structures located over planar and spherical lossy dielectric half-spaces by applying Green's function formulation and method of moments in the resonance region and under "high contrast approximation" (HCA). For this purpose, in the calculations of the impedance matrix and the potential column of the moment system, we employ the Green functions of King valid for arbitrary range under HCA and the asymptotic (far field) Green functions for planar and spherical impedance surfaces delivered by Norton and Wait, respectively. For a verification of the developed codes, the current distributions obtained under plane wave illumination on the arms of a cross shaped thin wire structure are compared to the same results obtained by the commercial software SNECTM. Various illustrations for the scattered electrical field from a thin wire plate located over planar and spherical half-spaces are also presented.

العلاقة: Makale - Uluslararası Hakemli Dergi; F-2007/37; Applied Computational Electromagnetics Society Journal; Yurt içi; Zor, Ö. ve Polat, B. (2011). "An implementation of king's green functions in thin wire scattering problems". Applied Computational Electromagnetics Society Journal, 26(12), Special Issue, 1024-1038.; http://hdl.handle.net/11452/24760Test; 000301007900009; 2-s2.0-84861323603; 1024; 1038; 26; 12, Special Issue

الإتاحة: http://hdl.handle.net/11452/24760Test

المساهمون: Uludağ Üniversitesi/Mühendislik Fakültesi/Elektrik ve Elektronik Mühendisliği Bölümü., Yalçın, Uǧur, AAG-8951-2021, 16023664100

مصطلحات موضوعية: Optics, Uniform asymptotic theory, Maggi-rubinowicz theory, Half-plane problem, Wedge, Physical optics, Wave propagation, Boundary diffraction waves, Diffraction problem, Impedance half-plane, Impedance surface, Modified theory of physical optics, Numerical results, Surface impedances, Vector potential, Diffraction, Half-Plane, Wave Diffraction

الوصف: Uniform diffracted fields from impedance surfaces are investigated by the extended theory of boundary diffraction wave (ETBDW). The new vector potential of the ETBDW is constructed by considering the pseudoimpedance boundary condition. The method is applied to the diffraction problem from an impedance half-plane. It is shown that the total fields from an impedance half-plane reduce to the case of a perfectly electric or magnetic conducting and opaque half-plane for special values of surface impedance. The total and diffracted fields are compared numerically with the exact solution for the impedance half-plane and modified theory of physical optics (MTPO) solution for an impedance wedge. The numerical results show that the field expressions are in very good agreement with the exact and MTPO solutions.

العلاقة: Makale - Uluslararası Hakemli Dergi; Applied Optics; Yalçın, U. vd. (2011). "Analysis of diffracted fields with the extended theory of the boundary diffraction wave for impedance surfaces". Applied Optics, 50(3), 296-302.; https://doi.org/10.1364/AO.50.000296Test; https://opg.optica.org/ao/abstract.cfm?uri=ao-50-3-296Test; http://hdl.handle.net/11452/25380Test; 000286507600010; 2-s2.0-78751615252; 296; 302; 50

الإتاحة: https://doi.org/10.1364/AO.50.000296Test
http://hdl.handle.net/11452/25380Test
https://opg.optica.org/ao/abstract.cfm?uri=ao-50-3-296Test

المؤلفون: Polat, Burak

المساهمون: Uludağ Üniversitesi/Mühendislik Fakültesi/Elektrik ve Elektronik Mühendisliği Bölümü., Zor, Ömer, 36976857500

مصطلحات موضوعية: Engineering, Telecommunications, Electromagnetic scattering, Method of moments, Sommerfeld problem, Thin wires, Vertical electric-dipole, Radio-wave propagation, Electromagnetic-field, Inhomogeneous earth, Conducting bodies, Dielectric layer, Grid model, Half-space, Radiation, Surface, Dielectric materials, Electromagnetic wave scattering, Spheres, Verification, Commercial software, Current distribution, Electrical field, Far field, Green function, Half spaces, High contrast, Impedance matrices, Impedance surface, Lossy dielectrics

الوصف: We investigate electromagnetic scattering from metallic thin wire structures located over planar and spherical lossy dielectric half-spaces by applying Green's function formulation and method of moments in the resonance region and under "high contrast approximation" (HCA). For this purpose, in the calculations of the impedance matrix and the potential column of the moment system, we employ the Green functions of King valid for arbitrary range under HCA and the asymptotic (far field) Green functions for planar and spherical impedance surfaces delivered by Norton and Wait, respectively. For a verification of the developed codes, the current distributions obtained under plane wave illumination on the arms of a cross shaped thin wire structure are compared to the same results obtained by the commercial software SNECTM. Various illustrations for the scattered electrical field from a thin wire plate located over planar and spherical half-spaces are also presented.

العلاقة: Makale - Uluslararası Hakemli Dergi; F-2007/37; Applied Computational Electromagnetics Society Journal; Yurt içi; Zor, Ö. ve Polat, B. (2011). "An implementation of king's green functions in thin wire scattering problems". Applied Computational Electromagnetics Society Journal, 26(12), Special Issue, 1024-1038.; http://hdl.handle.net/11452/24760Test; 000301007900009; 2-s2.0-84861323603; 1024; 1038; 26; 12, Special Issue

الإتاحة: http://hdl.handle.net/11452/24760Test

المساهمون: Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Matematik Bölümü., orcid:0000-0003-4732-5753, Yaşar, Emrullah, AAG-9947-2021, 23471031300

مصطلحات موضوعية: Ostrovsky equation, Improved tanh function method, Travelling wave solutions, EXP-function method, Nonlinear evolution-equations, Solitons, Mathematics, Differential equations, Ordinary differential equations, Riccati equations, Wave propagation, Wave transmission, Exact solution, Improved tanh function methods, Nonlinear ordinary differential equation, Travelling wave solution, Nonlinear equations, applied, Solitary Wave Solution, Optical Solitons, (G′/G)-expansion Method

الوصف: In this work, new travelling wave solutions to the Ostrovsky equation are studied by employing the improved tanh function method. With this method, the Ostrovsky equation is reduced to the nonlinear ordinary differential equation and then the different types of exact solutions are derived based on the solutions of the Riccati equation. We will compare our solutions with those gained by the other methods.

العلاقة: Makale - Uluslararası Hakemli Dergi; Applied Mathematics and Computation; Yaşar, E. (2010). "New travelling wave solutions to the Ostrovsky equation". Applied Mathematics and Computation, 216(11), 3191-3194.; https://doi.org/10.1016/j.amc.2010.04.038Test; https://www.sciencedirect.com/science/article/pii/S0096300310004649Test; http://hdl.handle.net/11452/25399Test; 000278543500007; 2-s2.0-78049297596; 3191; 3194; 216; 11

الإتاحة: https://doi.org/10.1016/j.amc.2010.04.038Test
http://hdl.handle.net/11452/25399Test
https://www.sciencedirect.com/science/article/pii/S0096300310004649Test