Now showing items 200-219 of 320

    • Nanohole-based phase gradient metasurfaces for light manipulation 

      Yılmaz, Nazmi; Özer, Ahmet; Özdemir, Aytekin; Kurt, Hamza ( Institute of Physics Publishing, 2019-05)
      The commonly accepted approach for metasurface design utilizes nanopillars with varying diameters. In this study, contrary to usual design approach, we propose and design highly efficient, broadband and polarization-independent ...
    • Nanosphere Concentrated Photovoltaics with Shape Control 

      Esmaeilzad, Nasim Seyedpour; Demir, Ahmet Kemal; Hajivandi, Jamileh; Ciftpinar, Hande; Turan, Rasit; Kurt, Hamza; Bek, Alpan (WILEY-V C H VERLAG GMBH, 2020-12)
      Dielectric colloidal nanospheres (NSs) are promising candidates for light management in photonic devices such as solar cells (SCs). NS arrays can direct the broad incident solar radiation into a set of tighter foci, at ...
    • Nanostructures for highly efficient infrared detection 

      Gailevicius, D.; Hayran, Z.; Turduev, M.; Kurt, Hamza; Juodkazis, S.; Malinauskas, M.; Mizeikis, V.; Staliunas, K. (SPIE, 2017-01)
      We propose a high sensitivity photodetection tool at near-infrared frequencies, based on a principle of slowed- and stopped-light in chirped photonic micro/nano-structures. The main goal is to substantially increase the ...
    • Neural network based instant parameter prediction for wireless sensor network optimization models 

      Akbaş, Ayhan; Yıldız, Hüseyin Uğur; Özbayoğlu, Ahmet Murat; Tavlı, Bülent (Springer New York LLC, 2019-08)
      Optimal operation configuration of a Wireless Sensor Network (WSN) can be determined by utilizing exact mathematical programming techniques such as Mixed Integer Programming (MIP). However, computational complexities of ...
    • A New Navigation System for Unmanned Aerial Vehicles in Global Positioning System-Denied Environments Based On Image Registration with Mutual Information and Deep Learning 

      Sahin, Cagla; Yetik, Imam Şamil (Institute of Navigation, 2020-01)
      In this paper, we develop an alternative navigation system for Unmanned Aerial Vehicle (UAV) in Global Positioning Systems (GPS)-denied environment. We use two image inputs, one is acquired with an on-board camera placed ...
    • Newton-raphson methods in aircraft trim: A comparative study 

      Millidere, M.; Karaman, U.; Uslu, S.; Kasnakoğlu, Coşku; Çimen, T. (American Institute of Aeronautics and Astronautics Inc, AIAA, 2020-06)
      While simulating and analyzing air-vehicle motion during flight, it is not possible to use the nonlinear model directly without appropriate initial conditions. The initial condition stands for a point about which air-vehicle ...
    • Noise reduction filter optimization for prostate cancer localization 

      Arın, Efe; Yetik, İmam Şamil (Institute of Electrical and Electronics Engineers Inc., 2019)
      Multispectral Magnetic Resonance Imaging (MRI) images are commonly used in prostate cancer diagnosis. However noise in raw data makes it difficult to process images. Therefore MR images must be filtered as a pre-processing ...
    • Non-diffraction bloch modes in low-symmetric photonic crystals 

      Gumus, M.; Giden, I.H.; |Turduev, M.; Kurt, Hamza (OSA - The Optical Society, 2017)
      [No abstract available]
    • Nonlinear modelling and control of the flow over aerofoils using CFD simulations 

      Karaca, H.D.; Özen, G.D.; Kasnakoğlu, Coşku (Elsevier B.V., 2016-09)
      A simulation based approach for nonlinear dynamical modelling and feedback control of the drag to lift ratio for aerofoils is investigated through case studies involving NACA 23012, ag13 and b737a aerofoils. The flow around ...
    • Nonreciprocal light transmission in gain-loss modulated Micro ring resonators 

      Giden, I.H.; Dadashi, K.; Botey, M.; Herrero, R.; Staliunas, K.; Kurt, Hamza (IEEE Computer Society, 2015)
      We propose a new type of add-drop Micro ring resonator that is made up of gain and loss materials. In all-dielectric linear systems, light transmission is reciprocal: A symmetric transmission spectrum is observed when an ...
    • Numerical and experimental demonstration of a wavelength demultiplexer design by point-defect cavity coupled to a tapered photonic crystal waveguide 

      Hayran, Zeki; Turduev, Mirbek; Botey, Muriel; Herrero, Ramon; Staliunas, Kestutis; Kurt, Hamza (Optical Soc Amer, 2016-01-01)
      We propose and experimentally demonstrate a demultiplexer with point-defect resonators and a reflection feedback mechanism in a photonic crystal waveguide (PCW). A tapered PCW has been chosen as the necessary reflector, ...
    • OFDMA-based multicast with multiple base stations 

      Kazez, Ahmet Cihat; Girici, Tolga (Tubitak Scientific & Technical Research Council Turkey, 2015)
      We consider an orthogonal frequency division multiple access (OFDMA)-based multicast system where multiple base stations transmit a multicast session to a multicast group. The goal is to maximize the multicast rate (i.e. ...
    • On The Eddy Current Losses in Metallic Towers 

      Mahariq, Ibrahim; Beryozkina, Svetlana; Mohammed, Huda; Kurt, Hamza (Diponegoro university Indonesia - Center of Biomass and Renewable Energy (CBIORE), 2020-02)
      The existence of magnetic field around high-voltage overhead transmission lines or low-voltage distribution lines is a known fact and well-studied in the literature. However. the interaction of this magnetic field either ...
    • On-and off-optical-resonance dynamics of dielectric microcylinders under plane wave illumination 

      Mahariq, I.;  Kurt, Hamza (OSA - The Optical Society, 2015-06)
      We explore the on-resonance and off-resonance optical response of dielectric cylinders excited by normal incident plane waves. Both the analytical method, based on Mie theory, and the numerical method, implemented with the ...
    • On-chip photonic filter design via objective-first algorithm 

      Tutgun, M.; Alpkilic, A.M.; Yilmaz, Y.A.; Yeltik, A.; Yilmaz, D.; Kurt, Hamza (SPIE, 2018)
      We propose and demonstrate compact on-chip optical filters with ultra-high efficiencies, which are designed via the recently-emerged objective-first inverse design algorithm. The all-dielectric high-pass, low-pass and ...
    • An Open Source, Modular and Scalable HIFU Driver System 

      Ozum, H. Emre; Yetik, Hasan; Kilinc, M. Sait; Ergün, Arif Şanlı (IEEE, 2017-10)
      High-intensity focused ultrasound (HIFU) have been an attractive research topic for some time now. HIFU studies have started with single-element transducers, but using arrays provide the opportunity to scan the focal point ...
    • Optical modulators and biochemical sensors based on low-symmetric nanophotonic structures with interferometric configurations 

      Yasa, Utku G.; Giden, Ibrahim H.; Kurt, Hamza (SPIE, 2018-02)
      Low-symmetric photonic crystals (PCs) have a high level of tunability in terms of their iso-frequency contours or refractive indices via angular orientations as well as spatial variations of unit cell elements. This ...
    • Optical Sensing Device through Monitoring Cut-off Wavelength of Asymmetric Transmission 

      Yilmaz, Nazmi; Ozer, Ahmet; Bagci, Fehim T.; Kilic, Osman O.; Yildirim, Tolga; Ozdemir, Aytekin; Kocer, Hasan; Kurt, Hamza (Institute of Electrical and Electronics Engineers Inc., 2018-07)
      In this study, we propose and design a subwavelength optical sensing device to detect material refractive index through metallic structure providing asymmetric transmission behavior. The proposed metallic structure consists ...
    • An Optical Sensor Design Using Surface Modes of Low-Symmetric Photonic Crystals 

      Erim, Nur; Erim, Muhammed Necip; Kurt, Hamza (Institute of Electrical and Electronics Engineers Inc., 2019)
      In this paper, an optical sensor design is proposed with low-symmetric photonic crystals that support surface modes. In order to obtain low symmetry, rotational symmetry is broken within the unit cell size while translational ...
    • Optically-Thin Broadband Graphene-Membrane Photodetector 

      Moein, Tania; Gailevicius, Darius; Katkus, Tomas; Ng, Soon Hock; Lundgaard, Stefan; Moss, David J.; Kurt, Hamza; Mizeikis, Vygantas; Staliunas, Kestutis; Malinauskas, Mangirdas; Juodkazis, Saulius (MDPI AG, 2020-02)
      A broadband graphene-on-Si3N4-membrane photodetector for the visible-IR spectral range is realised by simple lithography and deposition techniques. Photo-current is produced upon illumination due to presence of the build-in ...