Browsing by Keywords "Frequencies"

Now showing items 1-12 of 12

    • Anharmonicity of zone-center optical phonons: Raman scattering spectra of GaSe0.5S0.5 layered crystal 

      Gasanly, N. M.; Aydınlı, Atilla; Kocabas, C.; Özkan H. (IOPscience, 2002)
      The temperature dependencies (10-300 K) of the eight Raman-active mode frequencies and linewidths in GaSe0.5S0.5 layered crystal have been measured in the frequency range from 10 to 320 cm-1. We observed softening and ...

    • Aviation risk perception: a comparison between experts and novices 

      Thomson, M. E.; Önkal D.; Avcioǧlu, A.; Goodwin, P. (Wiley-Blackwell Publishing, 2004)
      This article describes an exploratory investigation of the risk perceptions of experts and novices in relation to helicopter operations, under conditions where the participants are matched on various characteristics ...

    • Band-dropping via coupled photonic crystal waveguides 

      Bayındır, Mehmet; Özbay, Ekmel (Optical Society of American (OSA), 2002)
      We observe the dropping of electromagnetic waves having a specific frequency or a certain frequency band in two-dimensional dielectric photonic crystals. The single frequency is dropped via cavity-waveguide coupling. ...

    • Classification of closed and open shell pistachio nuts using principal component analysis of impact acoustics 

      Çetin, A. Enis; Pearson, T. C.; Tewfik, A. H. (IEEE, 2004-05)
      An algorithm was developed to separate pistachio nuts with closed-shells from those with open-shells. It was observed that upon impact on a steel plate, nuts with closed-shells emit different sounds than nuts with open-shells. ...

    • Dynamical correlations in Coulomb drag effect 

      Tanatar, Bilal; Davoudi, B.; Hu, B.Y.-K. (Elsevier, 2003)
      Motivated by recent Coulomb drag experiments in pairs of low-density two-dimensional (2D) electron gases, we investigate the influence of correlation effects on the interlayer drag rate as a function of temperature. We use ...

    • Electromagnetically induced left-handedness in a dense gas of three-level atoms 

      Oktel, M. Ö.; Müstecaphoǧlu, Ö. E. (The American Physical Society, 2004)
      Ways in which a three-level system can be used to change the frequency-dependent magnetic permeability of an atomic gas were discussed. The resulting macroscopic electrodynamics was also discussed. The two levels were ...

    • Nonplanar trapezoidal tooth log-periodic antennas: design and electromagnetic modeling 

      Ergül, Özgür; Gürel, Levent (Wiley-Blackwell, 2005)
      Nonplanar trapezoidal tooth log-periodic (LP) antennas are investigated by combining the wisdom of theoretical design procedures with the power of accurate numerical simulation environments. Once the theoretical design is ...

    • Perspective projections in the space-frequency plane and fractional Fourier transforms 

      Yetik, I. S.; Özaktaş, Haldun M.; Barshan, B.; Onural, L. (OSA Publishing, 2000-07-06)
      Perspective projections in the space-frequency plane are analyzed, and it is shown that under certain conditions they can he approximately modeled in terms of the fractional Fourier transform, The region of validity of the ...

    • Phase-matched self-doubling optical parametric oscillator 

      Kartaloğlu, T.; Köprülü, K. G.; Aytür, O. (Optical Society of America, 1997-03-01)
      We report a synchronously pumped intracavity frequency-doubled optical parametric oscillator that employs a single KTiOPO4 crystal for both parametric generation and frequency doubling. Both nonlinear processes are phase ...

    • Reduced-order model-based feedback controller design for subsonic cavity flows 

      Yuan, X.; Caraballo, E.; Yan, P.; Özbay, Hitay; Serrani, A.; DeBonis, J.; Myatt, J. H.; Samimy, M. (American Institute of Aeronautics and Astronautics, 2005-01)
      This paper explores feedback controller design for cavity flows based on reduced-order models derived using Proper Orthogonal Decomposition (POD) along with Galerkin projection method. Our preliminary analysis shows that ...

    • SU(2)-path integral investigation of Holstein dimer 

      Hakioğlu, A. T.; Ivanov, V. A.; Zhuravlev, M. Ye. (Elsevier Science Publishers B.V., Amsterdam, Netherlands, 2000)
      The SU(2) coherent state path integral is used to investigate the partition function of the Holstein dimer. This approach naturally takes into account the symmetry of the model. The ground-state energy and the number of ...

    • Subwavelength resolution in a two-dimensional photonic-crystal-based superlens 

      Cubukcu, E.; Aydin, K.; Özbay, Ekmel; Foteinopolou, S.; Soukoulis, C. M. (American Physical Society, 2003)
      The experimental and theoretical demonstration of a single-beam negative refraction and a superlensing effect in 2D photonic crystals was reported. As such, negative refraction was observed for the incidence angles of >20°. ...