Now showing items 1-16 of 16

    • 3D electron density estimation in the ionosphere 

      Tuna, Hakan; Arıkan, Orhan; Arıkan, F. (IEEE, 2014)
      Ionosphere has ion distribution which is variable in space and time. There have been physical and empirical studies for modeling the ionosphere. International Reference Ionosphere extended to Plasmasphere (IRI-Plas) is the ...
    • Average error in recovery of sparse signals and discrete fourier transform 

      Özçelikkale, Ayça; Yüksel, S.; Özaktaş Haldun M. (IEEE, 2012-04)
      In compressive sensing framework it has been shown that a sparse signal can be successfully recovered from a few random measurements. The Discrete Fourier Transform (DFT) is one of the transforms that provide the best ...
    • A complexity-reduced ML parametric signal reconstruction method 

      Deprem, Z.; Leblebicioglu, K.; Arkan O.; Çetin, A.E. (2011)
      The problem of component estimation from a multicomponent signal in additive white Gaussian noise is considered. A parametric ML approach, where all components are represented as a multiplication of a polynomial amplitude ...
    • Cooperative transmission for multiuser MIMO systems 

      Yazarel, Y.K.; Aktaş, D. (2008)
      In this work, we investigate the problem of jointly determining the optimal transmission scheme at the base stations in a cooperative multiuser multiple antenna system. In this optimization problem, different than majority ...
    • Effects of signal randomization on performance of binary communications systems 

      Göken, Çağrı; Gezici, Sinan; Arıkan, Orhan (IEEE, 2010)
      In this paper, effects of signal randomization are studied for binary communications systems. First, it is stated that the average probability of error for a power-constrained binary communications system is minimized when ...
    • Noise enhancement in joint detection and estimation systems 

      Akbay, A.B.; Gezici, S. (IEEE Computer Society, 2014)
      Adding noise to inputs of some suboptimal detectors or estimators can improve their performance under certain conditions. In this study, a noise enhanced joint detection and estimation system is investigated. Maximization ...
    • Non-linear pricing by convex duality 

      Pınar, M. Ç. (Elsevier, 2015)
      We consider the pricing problem of a risk-neutral monopolist who produces (at a cost) and offers an infinitely divisible good to a single potential buyer that can be of a finite number of (single dimensional) types. The ...
    • On the accuracy of uniform polyhedral approximations of the copositive cone 

      Yıldırım, A. (Taylor & Francis, 2012)
      We consider linear optimization problems over the cone of copositive matrices. Such conic optimization problems, called copositive programs, arise from the reformulation of a wide variety of difficult optimization problems. ...
    • An optimal network dimensioning and initial energy assignment minimizing the monetary cost of a heterogeneous WSN 

      Sevgi, Cüneyt; Kocyigit, A. (IEEE, 2009)
      In this paper, a novel method is proposed to dimension a randomly deployed heterogeneous Wireless Sensor Network (WSN) of minimum monetary cost satisfying minimum coverage and minimum lifetime requirements. We consider ...
    • Particle swarm optimization based channel identification in cross-ambiguity domain 

      Güldoğan, Mehmet Burak; Arıkan, Orhan (IEEE, 2010)
      In this paper, a new array signal processing technique by using particle swarm optimization (PSO) is proposed to identify multipath channel parameters. The proposed technique provides estimates to the channel parameters ...
    • A particle swarm optimization based SAR motion compensation algorithm for target image reconstruction 

      Uğur, Salih; Arıkan, Orhan (IEEE, 2010)
      A new SAR motion compensation algorithm is proposed for robust reconstruction of target images even under large deviations of the platform from intended flight path. Phase error due to flight path deviations is estimated ...
    • Pipelined fission for stream programs with dynamic selectivity and partitioned state 

      Gedik, B.; Özsema, H. G.; Öztürk, Ö. (Academic Press, 2016)
      There is an ever increasing rate of digital information available in the form of online data streams. In many application domains, high throughput processing of such data is a critical requirement for keeping up with the ...
    • Projections onto convex sets (POCS) based optimization by lifting 

      Çetin, A. Enis; Bozkurt, Alican; Günay, Osman; Habiboglu, Yusuf Hakan; Köse, K.; Onaran, İbrahim; Tofighi, Mohammad; Sevimli, Rasim Akın (IEEE, 2013)
      A new optimization technique based on the projections onto convex space (POCS) framework for solving convex and some non-convex optimization problems are presented. The dimension of the minimization problem is lifted by ...
    • Quality control chart design under jidoka 

      Berk, E.; Toy, A. Ö. (John Wiley & Sons, Inc., 2009)
      We consider design of control charts in the presence of machine stoppages that are exogenously imposed (as under jidoka practices). Each stoppage creates an opportunity for inspection/repair at reduced cost. We first model ...
    • Sparse ground-penetrating radar imaging method for off-the-grid target problem 

      Gurbuz, A. C.; Teke, O.; Arikan, O. (SPIE, 2013)
      Spatial sparsity of the target space in subsurface or through-the-wall imaging applications has been successfully used within the compressive-sensing framework to decrease the data acquisition load in practical systems, ...
    • Ultra-wideband orthogonal pulse shape set design by using Hermite-Gaussian functions 

      Alp, Yaşar Kemal; Dedeoǧlu, Mehmet; Arıkan, Orhan (IEEE, 2012)
      Ultra-Wideband (UWB) communication systems have been developed for short distance, high data rate communications. To avoid interfering with the existing systems in the same environment, very short duration pulses used by ...