254 research outputs found
Modal properties of parallel plate waveguide partially loaded with double negative materials
No full textPekmezci, Ayşegül (Dogus Author) -- Topuz, Ercan (Dogus Author)Properties of eigen-solutions in parallel plate waveguides partially loaded with Lorentz type Double Negative Materials (DNG), modelled by lossless/lossy, identical/non-identical electric, magnetic parameters are presented. Modal cut-off phenomena associated with surface waves, transitions between evanescent/propagating, forward/backward waves and their dependence on frequency, filling factor and dispersive material parameters are investigated. Novel conditions are given for the existence of surface waves and for the emergence of complex eigenvalues in the absence of losses, and supported with numerical results of exact frequency domain analysis
Finite difference time domain formulation for epsilon-negative medium using wave equation
No full textPekmezci, Ayşegül (Dogus Author) -- Topuz, Ercan (Dogus Author)A novel approach utilizing one-dimensional (1D) wave equation based finite difference time domain (FDTD) formulations for Lorentz-type Epsilon-Negative (ENG) medium is developed. To demonstrate the validity and accuracy of the formulation, reflection of a plane wave normally incident at free spaceENG interface is compared with the analytical solution. Moreover, propagation characteristics of Lorentz-type ENG medium is investigated using the FDTD formulations both for wave equation and Maxwell's curl equations in 1D case. Comparisons of memory and computational time requirements of both formulations are given
First and second order mur type ABCs for DNG media
No full textPekmezci, Ayşegül (Dogus Author) -- Topuz, Ercan (Dogus Author)Reflections from boundaries of the FDTD computational domain lead to inaccurate, even unstable codes when dealing with problems involving double negative (DNG) materials. Here, an efficient and simple algorithm is presented for terminating FDTD in DNG medium which is based on first and second order Mur’s absorbing boundary conditions (ABC). FDTD update equations for Mur’s ABC formulations are obtained from frequency domain one-way wave equations using piecewise linear recursive convolution (PLRC) method. Numerical examples are given both for 1D and 2D scenarios to demonstrate the validity and stability of the proposed Mur formulations, and its advantages over uniaxial perfectly matched layer (UPML) in reducing computational time and memory requirements
Comment on the “NASPGHAN Position Paper on the Diagnosis and Management of Pediatric Acute Liver Failure”
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A research on the relationship between top managers’ intelligence and their ideas about business process reengineering: consideration of emotionality and spirituality
No full textAyrancı, Evren (Arel Author), Ertuğrul Ayrancı, Ayşegül (Arel Author)With its dramatic boosts to effectiveness and efficiency, Business Process Reengineering (BPR) is a crucial tool for business success, thus countless businesses in various industriesare inspired to get its benefits. Though these benefits are heavily related to technical matters such as cost, speed and quality; there is also a human side associated with BPR. This study is interested in an odd dimension of this human side: top managers’ emotional and spiritual intelligence. More precisely, top managers’ emotional and spiritual intelligences are believed to be related with their ideas about the targets and critical success factors of BPR. This study not only scrutinizes this belief, but also fills in a great gap as the literature does not offer a similar research. The operationalization stage of the study includes data from top managers of businesses in İkitelli Organized Industrial Zone (OIZ) and the findings clearly point out that top managers’ spiritual intelligence is strongly and positively related with their ideas about BPR whereas there is no connection between their emotional capabilities and their mentioned ideas
First appartment buildings in European Side of Bosphorus and their conservation values
No full textOrhan Şahan, Ayşegül (Dogus Author)20. yüzyılın mimari miraslarından biri olduğu düşünülen kat apartmanları, II. Dünya Savaşı’ndan sonra ülkemizde yoğun bir şekilde inşa edilmiştir. Makalenin amacı, Boğaziçi’nin Avrupa Sahili’nde inşa edilmiş kat apartmanlarının korunmalarını gerektiren özel değerlerini belirleyerek, bu yapılar ile ilgili uzmanlar tarafından gerçekleştirilecek koruma çalışmalarına veri oluşturmaktır. II. Dunya Savaşı’ndan sonra ülkemizdeki toplumsal, sosyo-kültürel, ekonomik, mimari ve teknolojik gelişmeler ışığında şekillenen kat apartmanlarında; eski, tasarım, üslup, mimari müellif, eski strüktür-malzeme, standartlaşma, kişisel anı, konut stoğu, işlevsellik, çevresellik, grup-çokluk-homojenlik, kentsel kimlik özellikleri kültür varlıkları olarak korunmalarını gerektiren özel değerleri olarak belirlenmiştir. Kat apartmanlarının özel değerleri aracılığıyla ülkemizin sağlayacağı; mimari, kentsel, sosyo-kültürel ve ekonomik kazanımlar açıklanmıştır.Apartments thought to be one of the architectural heritages of the 20th century; it was built intensely in our country after World War II. The aim of the article is to establish the specific values that need to protect the apartments built on the European Coast of the Bosphorus and to create data for the conservation work to be carried out by experts on these buildings. After the World War II, in the floor apartments shaped by the social, socio-cultural, economic, architectural and technological developments in our country; old, design, style, traditional structure-material, standardization, personal memory, residential stock, functionality, environmentalism, group-plural-homogeneity and urban identity are required to be preserved as cultural assets. The architectural, urban, socio-cultural and economic gains that our country will provide through the special values of the apartment buildings are explained
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