Now showing items 28-47 of 320

    • Backhaul-Aware Optimization of UAV Base Station Location and Bandwidth Allocation for Profit Maximization 

      Cicek, Cihan Tugrul; Gültekin, Hakan; Tavlı, Bülent; Yanikomeroglu, Halim (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2020)
      Unmanned Aerial Vehicle Base Stations (UAV-BSs) are envisioned to be an integral component of the next generation Wireless Communications Networks (WCNs) with a potential to create opportunities for enhancing the capacity ...
    • Backward propagation of surface slow light in photonic crystals through morphological diversity 

      Yeltik, Aydan; Yilmaz, Done; Kurt, Hamza (SPIE, 2018-04)
      We propose and demonstrate photonic crystals (PCs) providing backward-directional propagation of surface slow waves, which is significant for potential PC-based photonic applications. An effective pathway for backward ...
    • Biosensing With Asymmetric High Refractive Index Contrast Gratings 

      Erim, Nur; Erim, Muhammed Necip; Yilmaz, Done; Kurt, Hamza (IEEE-Inst Electrical Electronics Engineers Inc, 2016-10-15)
      We propose a novel label-free optical biosensor configuration based on a spectral refractive index sensing method by utilizing asymmetric high index contrast dielectric gratings. The characterization and performance ...
    • Broadband and polarization-independent asymmetric transmission of visible light through a three-dimensional trapezoidal metallic metasurface 

      Özer, Ahmet; Koçer, Hasan Erdinç; Kurt, Hamza (OSA - The Optical Society, 2018-09-01)
      In modern optical applications, it has become an important need to flow light unidirectionally. An optical diode realizes this task as an electrical counterpart manipulates the flow of electrons in semiconductor materials. ...
    • Broadband asymmetric light transmission based on all-dielectric metasurfaces in the visible spectrum 

      Özer, Ahmet; Yılmaz, Nazmi; Koçer, Hasan; Kurt, Hamza (IOP PUBLISHING LTD, 2019-05)
      An asymmetric transmission device composed of all dielectric phase gradient metasurfaces on the dielectric substrate in the visible wavelengths is proposed and designed. In order to verify its operation principle and ...
    • Broadband direction-dependent transmission of light with photonic crystal heterostructure grating 

      Yılmaz, Döne; Giden, İbrahim Halil; Kurt, Hamza (IOP Publishing Ltd., 2018-01-17)
      Direction-dependent light transmission is a remarkable phenomenon owing to its great potential to be used in optical communication processing systems such as optical diodes, isolators and rectifiers. All these applications ...
    • Broadband directional cloaking using graded index structures 

      Oner, B.B.; Can, M.G.; Kurt, Hamza (IEEE Computer Society, 2014)
      We propose broadband two-dimensional cloaking designs based on isotropic and all dielectric lossless materials. The photonic structures are created by implementing artificially generated graded index (GRIN) media. The ...
    • Broadband one way propagation via dielectric waveguides with unequal effective index 

      Öner, B.B.; Üstün, K.; Kurt, H.; Okyay, A.K.; Turhan-Sayan, G. (Institute of Electrical and Electronics Engineers Inc., 2014-12)
      We present an efficient approach for broad band one way propagation of light by parallel and unequal dielectric waveguides leading different effective phase shifts. Three dimensional numerical simulations show that 30% ...
    • A broadband polarization-insensitive diffractive lens design for subwavelength focusing of light 

      Yıldırım, Bumin K.; Bor, Emre; Kurt, Hamza; Turduev, Mirbek (IEEE Computer Society, 2019)
      In this study, we propose the metaheuristic design of a polarization-insensitive diffractive lens. The designed lens structure consists of concentric dielectric rings with optimally modulated widths and heights. Here, the ...
    • Broadband self-collimation in C2 symmetric photonic crystals 

      Gümüş, Melike; Giden, İbrahim Halil; Kurt, Hamza (OSA - The Optical Society, 2018-06-01)
      In this study, we report a low-symmetric photonic crystal (PhC) structure that exhibits high coupling efficiency in a broadband frequency range with a tilted self-collimating capability. First, the analytical approach is ...
    • Chiral modes in 2D PT-symmetric nanostructures 

      Botey, M.; Herrero, R.; Turduev, M.; Giden, I.; Kurt, Hamza; Staliunas, K. (Springer Science and Business Media, LLC, 2016)
      We propose a 2-dimensonal PT-symmetric photonic honeycomb structure that supports chiral Block-likemodes being its excitation input and frequency dependent. We show that while the fundamental resonant frequency excites the ...
    • Classification of Electronic Devices With Power-Swept Signals Using Harmonic Radar 

      Hayvacı, Harun Taha; Ilbegi, Handan; Yetik, Imam Şamil (Institute of Electrical and Electronics Engineers Inc., 2020-06)
      A novel approach for classification of electronic devices using a harmonic radar is proposed in this article. We transmit single-tone time-varying signals with varying power to the electronic circuits under test (ECUTs). ...
    • Clustering-based device-to-device cache placement 

      Kazez, Ahmet Cihat; Girici, Tolga (Elsevier B.V., 2019)
      In this work we consider the problem of optimal cache placement in a D2D enabled cellular network. There are a number of helper devices in the area, which use their cached contents to help other users and offload traffic ...
    • Compact Fast-Switching DC and Resonant RF Drivers for a Dual-Mode Imaging and HIFU 2D CMUT Array 

      Stedman, Quintin; Gu, Lei; Pai, Chi-Nan; Rasmussen, Morten; Brenner, Kevin; Ma, Bo; Ergun, Arif Şanlı; Davila, Juan Rivas; Khuri-Yakub, Butrus (IEEE, 2019-10)
      We developed previously a 2D CMUT array with capability to both do imaging and generate HIFU for ablation of targeted tissues without collateral damage. This new technology allows a more compact HIFU system, when compared ...
    • Compact rainbow trapping and demultiplexing by photonic crystal waveguides 

      Giden, I.H.; Kurt, Hamza; Turduev, M.; Staliunas, K. (Institute of Electrical and Electronics Engineers Inc., 2014)
      Graded Index Photonic Crystals (GRIN PhCs) are artificial periodic materials that possess gradually varying effective refractive indices. GRIN profiles can be formed by adjusting the radii or the locations of PhC unit ...
    • Comparative analysis of performance of the SEPIC converter using LQR and PID controllers 

      Sel, A.; Güneş, U.; Elbir, Ö.; Kasnakoğlu, Coşku (Institute of Electrical and Electronics Engineers Inc., 2017-11)
      The purpose of this study is to design a LQR controller for the SEPIC (Single-Ended Primary-Inductor Converter) converter which is widely employed in industrial DC-DC power conversion and is also starting to see widespread ...
    • Comparative Analysis of Transmission Power Level and Packet Size Optimization Strategies for WSNs 

      Yıldız, Hüseyin Uğur; Kurt, Sinan; Tavlı, Bülent (Institute of Electrical and Electronics Engineers Inc., 2019)
      Wireless sensor networks (WSNs) are envisioned to be a widely utilized technology in a smart grid (SG). Maximizing the network lifetime (NL) of WSNs in SG deployments is necessary to provide reliability and efficiency of ...
    • Comparing and Developing PID and sliding mode Controllers for Quadrotor 

      Cömert, C.; Kasnakoğlu, Coşku (International Journal Of Mechanical Engineering And Robotics Research, 2017-05)
      This paper provides information about controller design for quadrotors which became an essential research topic. Sliding modecontrol (SMC) provides better solutions to problems that can be caused by model discrepancies.F ...
    • A Comparison of H8-Synthesis and Feedback Linearization for Rotary Inverted Pendulum 

      Gunes, U.; Sel, A.; Kurkcu, B.; Kasnakoğlu, Coşku (Institute of Electrical and Electronics Engineers Inc., 2020-07)
      This paper investigates the performance comparison of H8 based control and feedback linearization. The comparison is conducted on a challenging rotary inverted pendulum (RIP) system. The main difficulty of controlling RIP ...
    • Constant Envelope Precoding and Non-Orthogonal Multiple Access for Massive MIMO Systems 

      Ozcan, T.; Yüksel, Melda (Institute of Electrical and Electronics Engineers Inc., 2020-10)
      Constant Envelope (CE) precoding is a transmission technique, which provides efficient power amplification and can be realised with a single radio frequency (RF) chain at the multi-antenna transmitter. In this paper, we ...