Now showing items 1-20 of 273

    • Accelerating beam generation via all-dielectric metasurfaces 

      Yılmaz, Nazmi; Bağcı, Fehim Taha; Özer, Ahmet; Kurt, Hamza (SPIE, 2019)
      All-dielectric metasurfaces are unique component to control optical wavefront with high transmission or reflection coefficient. Recently, accelerating beam, which propagates along curved arbitrary trajectories, has been ...
    • Active beam steering and afocal zooming by nematic liquid crystal-infiltrated graded index photonic structures 

      Babayigit, Ceren; Kurt, Hamza; Turduev, Mirbek (Institute of Physics Publishing, 2019)
      This study presents active beam steering and afocal zooming of light by incorporating liquid crystals (LCs) with graded index photonic crystals (GRIN PCs). The GRIN PC structures are composed of low refractive index polymer ...
    • Active Fault Detection in Linear Controller Hardware with Sine Signal 

      Ozkan, M.; Kasnakoğlu, Coşku (Institute of Electrical and Electronics Engineers Inc., 2020-04)
      In this paper, active fault detection is used to detect hardware failure in Linear Controller. Auxiliary test signal is chosen as sine signal. Then frequency and magnitude of sine signal is designed according to bode plot ...
    • Adaptive detection with diffuse multipath exploitation in partially homogeneous environments 

      Hayvacı, Harun Taha; Gülen, Seden Hazal ( Institute of Electrical and Electronics Engineers Inc., 2019)
      In this paper, we deal with the problem of detecting point-like targets in the presence of multipath under the assumption of a partially homogeneous Gaussian disturbance with unknown covariance matrix. Therefore, we introduce ...
    • Adaptive Graded Index Photonic Crystal Lens Design via Nematic Liquid Crystals 

      Giden, Ibrahim Halil; Eti, Neslihan; Rezaei, Behrooz; Kurt, Hamza (IEEE-Inst Electrical Electronics Engineers Inc, 2016-10)
      An adaptive graded index photonic crystal (GRIN PC) lens system is designed by using liquid crystal (LC) infiltration. LCs have the property to change their refractive indices when an external voltage is applied. This ...
    • Adaptive modulation for completion time minimization in wireless broadcast networks 

      Yüksel, Melda; Genc, Yasin (Elsevier Gmbh, Urban & Fischer Verlag, 2017)
      In this work we study the effect of hierarchical modulation on completion time minimization in wireless broadcast channels. Time needed to transmit all bits intended for a particular user is defined as its completion time. ...
    • All-dielectric metasurface lenses for focal plane arrays operating in mid-wave infrared spectrum 

      Yilmaz, Nazmi; Ozdemir, Aytekin; Bagci, Fehim T.; Takashima, Yuzuru; Kurt, Hamza (SPIE, 2018-08)
      Focal plane arrays (FPAs) as a two-dimensional detector pixel matrix positioned in the focal plane of an optical system have been developed continuously for obtaining higher resolution. On the other hand, for developing ...
    • All-Dielectric Self-Cloaked Structures 

      Hayran, Zeki; Kurt, Hamza; Herrero, Ramon; Botey, Muriel M.; Staliunas, K. (American Chemical Society, 2018-05-16)
      A general procedure to design objects that are intrinsically invisible (without the necessity of an external cloak) has not been demonstrated so far. Here we propose a flexible method to design such self-cloaked objects ...
    • Altitude Control for Small Fixed-Wing Aircraft Using H-infinity Loop-Shaping Method 

      Akyurek, Seyma; Kaynak, Unver; Kasnakoğlu, Coşku (Elsevier Science BV, 2016)
      Autopilot systems for UAVs without human pilots maintain the flight through an appropriate balance of aerodynamic forces autonomously. That is to say, they arc used to make flight missions more reliable and efficient. ...
    • The Analysis of RCS of Winged Almond Model with Ammunition and without Ammunition 

      Durlu, Caglayan; Hayvacı, Harun Taha (IEEE, 2017)
      In this paper, the design, analysis and numerical results of back scattering field of winged almond model with ammunition and without ammunition are presented. Simulations with using Physical Optics (PO) method in Ansys ...
    • Analysis of the Tradeoff Between Network Lifetime and k-connectivity in WSNs 

      Cobanlar, Muhammed; Akram, Vahid Khalilpour; Dagdeviren, Orhan; Tavlı, Bülent (IEEE, 2018)
      Reliability and network lifetime maximization are two important objectives when designing a Wireless Sensor Network (WSN). However, these two are conflicting objectives. To increase the reliability maintaining k-connectivity ...
    • Angular filtering by Bragg photonic microstructures fabricated by physical vapour deposition 

      Grineviciute, Lina; Babayigit, Ceren; Gailevicius, Darius; Bor, Emre; Turduev, Mirbek; Purlys, Vytautas; Tolenis, Tomas; Kurt, Hamza; Staliunas, Kestutis ( Elsevier B.V., 2019)
      We propose and experimentally demonstrate spatial filtering by photonic crystals in a Bragg configuration. Compared to the Laue configuration, where spatial filtering was already demonstrated before, the Bragg configuration ...
    • Application of Data Acquisition System for Superconducting Quantum Interface Devices (SQUID) at Remote Location 

      Balaban, Deniz; Bozbey, Ali (IEEE Computer Society, 2014)
      Together with technological developments related to the specific area, the scope of remote data acquisition systems has become widened. The usages of these kinds of systems prevent waste of time and labor. Therefore, in ...
    • Assessment of Wireless Sensor Network Lifetime Reduction due to Elimination of Critical Node Sets 

      Yildiz, Huseyin Ugur; Tavlı, Bülent; Kahjogh, Behnam Ojaghi (IEEE, 2017)
      Wireless Sensor Networks (WSN) are used in various critical monitoring applications such as military safety, environmental surveillance, etc. In such scenarios, it is common that WSN nodes are threatened by potential ...
    • Asymmetric light transmission by using 2D PT-symmetric photonic nanostructure 

      Turduev, M.; Botey, M.; Herrero, R.; Giden, I.; Kurt, Hamza; Staliunas, K. (Institute of Electrical and Electronics Engineers Inc., 2014-12)
      We propose for the first time a simple realization of a two-dimensional Parity-Time symmetric hexagonal shaped photonic structure composed of honeycomb lattice. The structure has a symmetric periodic modulation of the ...
    • Asymmetric Light Transmission in PT-Symmetric Microring Resonators 

      Giden, Ibrahim Halil; Dadashi, Khalil; Botey, Muriel; Herrero, Ramon; Staliunas, Kestutis; Kurt, Hamza (IEEE-Inst Electrical Electronics Engineers Inc, 2016)
      We propose a new type of add-drop microring resonator made of gain and loss materials. Microring resonators are compact, narrow band, and optical channel dropping filters. In such linear systems, light transmission to ...
    • Asymmetric transmission from a 2D PT-symmetric honeycomb nanostructure 

      Botey, M.; Herrero, R.; Turduev, M.; Zhao, D.; Giden, I.; Kurt, Hamza; Staliunas, K. (IEEE Computer Society, 2014)
      We propose a simple realization of a 2-dimensonal (2D) PT-symmetric photonic structure: a honeycomb arrangement of alternating cylinders with gain or loss in a dielectric background. The structure provides a periodic ...
    • Autonomous Face Detection and Tracking Using Quadrotor UAV 

      Karahan, M.; Kurt, Hamza; Kasnakoğlu, Coşku (Institute of Electrical and Electronics Engineers Inc., 2020-10)
      In this paper, human face detection and tracking system with a camera of the Quadrotor UAV is proposed. During flight, Quadrotor takes photos of the human face, records videos and sends these photos and videos to the ...
    • Autonomous Navigation of an Aircraft Using a NARX Recurrent Neural Network 

      Sezginer, K.; Kasnakoğlu, Coşku (Institute of Electrical and Electronics Engineers Inc., 2019-11)
      This paper explores autonomous aircraft navigation using machine learning approach focusing on the ground run and takeoff which is one of the most critical control problems in the aircraft navigation. A controller which ...
    • 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 ...