Now showing items 1-20 of 64

    • Accurate method for obtaining band gaps in conducting polymers using a DFT/hybrid approach 

      Salzner, U.; Pickup, P. G.; Poirier, R. A.; Lagowski, J. B. (American Chemical Society, 1998)
      DFT calculations on a series of oligomers have been used to estimate band gaps, ionization potentials, electron affinities, and bandwidths for polyacetylene, polythiophene, polypyrrole, polythiazole, and a thiophene - ...
    • Adaptive control design for nonlinear systems via successive approximations 

      Babaei, N.; Salamci, M. U.; Karakurt, A. H. (American Society of Mechanical Engineers, 2017)
      The paper presents an approach to the Model Reference Adaptive Control (MRAC) design for nonlinear dynamical systems. A nonlinear reference system is considered such that its response is designed to be stable via Successive ...
    • Animation of deformable models 

      Güdükbay U.; Özgüç, B. (Pergamon Press, 1994)
      Although kinematic modelling methods are adequate for describing the shapes of static objects, they are insufficient when it comes to producing realistic animation. Physically based modelling remedies this problem by ...
    • An approximate analytical method of analysis of a threshold maintenance policy for a multiphase multicomponent model 

      Anisimov, V. V.; Gürler, Ü. (Springer, 2003)
      A multicomponent system is investigated that consists of n identical unreliable components whose nonfailure operating time consists of a number of sequential phases with exponential times. A maintenance policy is studied ...
    • Approximations in compensator design: a duality 

      Özgüler, A. B.; Gündeş, A. N. (The Institution of Engineering and Technology (IET), 2002)
      In classical controller design, poles fat to the left of dominant poles are sometimes ignored. Similarly, in some proportional-integral compensation techniques, the controller zero is placed close to the origin and design ...
    • Automatic multimedia cross-modal correlation discovery 

      Pan J.-Y.; Yang H.-J.; Faloutsos, C.; Duygulu P. (2004)
      Given an image (or video clip, or audio song), how do we automatically assign keywords to it? The general problem is to find correlations across the media in a collection of multimedia objects like video clips, with colors, ...
    • Block SOR for Kronecker structured representations 

      Buchholz, P.; Dayar, T. (Elsevier, 2004)
      The Kronecker structure of a hierarchical Markovian model (HMM) induces nested block partitionings in the transition matrix of its underlying Markov chain. This paper shows how sparse real Schur factors of certain diagonal ...
    • Capacity bounds for an ultra-wideband channel model 

      Ankan, E. (2004)
      There is an ongoing effort by the IEEE 802.15.3a subcommittee to reach a UWB personal area network standard. We estimate the achievable rates for such networks using a channel model specified by the same group. The analysis ...
    • Collective modes in a quasi-one-dimensional, two-component electron liquid 

      Tanatar, B. (Pergamon Press, 1994)
      Under favorable conditions, a new collective mode besides the usual plasmons may exist in degenerate electron-hole liquids. We calculate the dispersion and damping of this new mode (called the acoustic plasmon mode) in a ...
    • Collective modes in flux line liquids 

      Tanatar, B.; Oral, A. (IOP, 2000)
      We study the collective modes of flux line liquids such as occur in the type-II superconductors of recent interest composed of two-dimensional layered structures. Starting from the vortex-vortex interaction and employing ...
    • Computation of holographic patterns between tilted planes 

      Esmer, G. B.; Onural, L. (S P I E - International Society for Optical Engineering, 2006)
      Computation of the diffraction pattern that gives the desired reconstruction of an object upon proper illumination is an important process in computer generated holography. A fast computational method, based on the plane ...
    • Computationally efficient wavelet affine invariant functions for shape recognition 

      Bala, E.; Cetin, A. E. (IEEE, 2004)
      An affine invariant function for object recognition is constructed from wavelet coefficients of the object boundary. In previous works, undecimated dyadic wavelet transform was used to construct affine invariant functions. ...
    • Confined optical phonon effects on the band gap renormalization in quantum wire structures 

      Bennett, C. R.; Güven, K.; Tanatar, B. (Elsevier Science, 1999)
      We consider the different approximations for the bandgap renormalization (BGR) within the random phase approximation (RPA), the quasi-static limit and the plasmon-pole approximation, and compare with the full result. We ...
    • Correlation effects in a one-dimensional electron gas with short-range interaction 

      Demirel, E.; Tanatar, B. (Pergamon Press, 1999)
      We study the correlation effects in a one-dimensional electron gas with repulsive delta-function interaction. The correlation effects are described by a local-field correction which takes into account the short-range ...
    • Cost-efficient approximation of linear systems with repeated and multi-channel filtering configurations 

      Kutay, M. A.; Erden, M. F.; Ozaktas, H. M.; Arikan, O.; Candan, Ç.; Güleryüz, Ö. (IEEE, Piscataway, NJ, United States, 1998)
      It is possible to obtain either exact realizations or useful approximations of linear systems or matrix-vector products arising in many different applications, by synthesizing them in the form of repeated or multi-channel ...
    • Coulomb drag effect in parallel cylindrical quantum wires 

      Tanatar, B. (Pergamon Press, 1996)
      We study the Coulomb drag rate for electrons in two parallel quantum wires. The double-quantum wire structure is modeled for a GaAs material with cylindrical wires having infinite potential barriers. The momentum transfer ...
    • Coupled optical microcavities in one-dimensional photonic bandgap structures 

      Bayindir, M.; Kural, C.; Ozbay, E. (Institute of Physics Publishing, 2001)
      We present a detailed theoretical and experimental study of the evanescent coupled optical microcavity modes in one-dimensional photonic bandgap structures. The coupled-cavity samples are fabricated by depositing alternating ...
    • Digital computation of the fractional Fourier transform 

      Ozaktas, H. M.; Arıkan, O.; Kutay, M. A.; Bozdağı, G. (Institute of Electrical and Electronics Engineers, 1996-09)
      An algorithm for efficient and accurate computation of the fractional Fourier transform is given. For signals with time-bandwidth product N, the presented algorithm computes the fractional transform in O(NlogN) time. A ...
    • Dynamical screening effects in hot-electron scattering from electron-hole plasma and LO-phonon modes in quantum wires 

      Bennett, C. R.; Tanatar, B.; Constantinou, N. C. (Elsevier, 1996)
      We present a fully dynamical and finite temperature study of the hot-electron momentum relaxation rate and the power loss in a coupled system of electron-hole plasma and bulk LO-phonons in a quantum wire structure. ...
    • Effect of cross-sectional geometry on the RPA plasmons of quantum wires 

      Bennett, C. R.; Tanatar, B.; Constantinou, N. C.; Babiker, M. (Pergamon Press, 1994)
      The effect of cross-sectional geometry on both the intrasubband plasmon and intersubband plasmon of a quantum wire is investigated within a two-subband RPA scheme. Exact analytical electronic wavefunctions for circular, ...