Browsing by Keywords "Relaxation processes"

Now showing items 1-15 of 15

    • Compressive sampling and adaptive multipath estimation 

      Pilancı, Mert; Arıkan, Orhan (IEEE, 2010)
      In many signal processing problems such as channel estimation and equalization, the problem reduces to a linear system of equations. In this proceeding we formulate and investigate linear equations systems with sparse ...

    • Dynamical screening effects in hot-electron scattering from electron-hole plasma and LO-phonon modes in quantum wires 

      Bennett, C. R.; Tanatar, Bilal; 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. ...

    • Electronic structure, insulator-metal transition and superconductivity in K-ET2X salts 

      Ivanov V.A.; Ugolkova, E.A.; Zhuravlev, M.Ye.; Hakioǧlu, T. (1998)
      The electronic structure and superconductivity of layered organic materials based on the bis(ethylenedithio)tetrathiafulvalene molecule (BEDT-TTF, hereafter ET) with essential intra-ET correlations of electrons are analysed. ...

    • Finite temperature studies of Te adsorption on Si(0 0 1) 

      Sen, P.; Çıracı, Salim; Batra, I. P.; Grein, C. H.; Sivananthan, S. (Elsevier, 2002)
      We perform first principles density functional calculations to investigate the adsorption of Te on the Si(0 0 1) surface from low coverage up to a monolayer coverage. At low coverage, a Te atom is adsorbed on top of the ...

    • FIR filter design by iterative convex relaxations with rank refinement 

      Dedeoğlu, Mehmet; Alp, Yaşar Kemal; Arıkan, Orhan (IEEE, 2014)
      Finite impulse response (FIR) filters have been a primary topic of digital signal processing since their inception. Although FIR filter design is an old problem, with the developments of fast convex solvers, convex modelling ...

    • High-energy electron relaxation and full-band electron dynamics in aluminium nitride 

      Bulutay, Ceyhun; Ridley, B. K.; Zakhleniuk, N. A. (Elsevier, 2002)
      Material properties of AlN, particularly its wide band gap around 6 eV, warrant its operation in the high-field transport regimes reaching MV/cm fields. In this theoretical work, we examine the full-band scattering of ...

    • Iterative technique for 3-D motion estimation in videophone applications 

      Bozdağı, Gözde; Tekalp, A. M.; Onural, Levent (IEEE, 1994-04)
      In object based coding of facial images, the accuracy of motion and depth parameter estimates strongly affects the coding efficiency. We propose an improved algorithm based on stochastic relaxation for 3-D motion and depth ...

    • Nanomechanics using an ultra-small amplitude AFM 

      Hoffmann, P. M.; Jeffery, S.; Oral, Ahmet; Grimble, R. A.; Özer, H. Özgür; Pethica, J. B. (Cambridge University Press, 2001)
      A new type of AFM is presented which allows for direct measurements of nanomechanical properties in ultra-high vacuum and liquid environments. The AFM is also capable to atomic-scale imaging of force gradients. This is ...

    • Noise-enhanced M-ary hypothesis-testing in the minimax framework 

      Bayram, Suat; Gezici, Sinan (IEEE, 2009-09)
      In this study, the effects of adding independent noise to observations of a suboptimal detector are studied for M-ary hypothesis-testing problems according to the minimax criterion. It is shown that the optimal additional ...

    • Phase-only beam synthesis by iterative semidefinite relaxations with rank refinement 

      Alp, Yaşar Kemal; Arıkan, Orhan; Bayri, A. (IEEE, 2013)
      In phased array antennas, by varying the complex element weights beam patterns with desired shapes can be synthesized and/or steered to desired directions. These complex weights can be implemented by using amplitude ...

    • Recovery of sparse perturbations in Least Squares problems 

      Pilanci, M.; Arıkan, Orhan (IEEE, 2011)
      We show that the exact recovery of sparse perturbations on the coefficient matrix in overdetermined Least Squares problems is possible for a large class of perturbation structures. The well established theory of Compressed ...

    • Stochastic signal design on the downlink of a multiuser communications system 

      Tutay, Mehmet Emin; Gezici, Sinan; Arıkan, Orhan (IEEE, 2012-06)
      Stochastic signal design is studied for the downlink of a multiuser communications system. First, a formulation is proposed for the joint design of optimal stochastic signals. Then, an approximate formulation, which can ...

    • Stochastic signaling under second and fourth moment constraints 

      Göken, Çağrı; Gezici, Sinan; Arıkan, Orhan (IEEE, 2010)
      Stochastic signaling is investigated under second and fourth moment constraints for the detection of scalar-valued binary signals in additive noise channels. Sufficient conditions are derived to determine when the use of ...

    • Theoretical assessment of electronic transport in InN 

      Bulutay, C.; Ridley, B. K. (Elsevier, 2004)
      Among the group-III nitrides, InN displays markedly unusual electronic transport characteristics due to its smaller effective mass, high peak velocity and high background electron concentration. First, a non-local empirical ...

    • Trapped interacting Bose gas in nonextensive statistical mechanics 

      Tanatar, Bilal (The American Physical Society, 2002)
      We study the Bose-Einstein condensation (BEC) phenomenon in an interacting trapped Bose gas using the semiclassical two-fluid model and nonextensive statistical mechanics. The effects of nonextensivity characterized by a ...