Arama Sonuçları

Listeleniyor 1 - 10 / 310
  • Yayın
    Sınıflandırma için diferansiyel mahremiyete dayalı öznitelik seçimi
    (Gazi Univ, Fac Engineering Architecture, 2018) Var, Esra; İnan, Ali
    Veri madenciliği ve makine öğrenmesi çözümlerinin en önemli ön aşamalarından biri yapılacak analizde kullanılacak verinin özniteliklerinin uygun bir alt kümesini belirlemektir. Sınıflandırma yöntemleri için bu işlem, bir özniteliğin sınıf niteliği ile ne oranda ilişkili olduğuna bakılarak yapılır. Kişisel gizliliği koruyan pek çok sınıflandırma çözümü bulunmaktadır. Ancak bu yöntemler için öznitelik seçimi yapan çözümler geliştirilmemiştir. Bu çalışmada, istatistiksel veritabanı güvenliğinde bilinen en kapsamlı ve güvenli çözüm olan diferansiyel mahremiyete dayalı özgün öznitelik seçimi yöntemleri sunulmaktadır. Önerilen bu yöntemler, yaygın olarak kullanılan bir veri madenciliği kütüphanesi olan WEKA ile entegre edilmiş ve deney sonuçları ile önerilen çözümlerin sınıflandırma başarımına olumlu etkileri gösterilmiştir.
  • Yayın
    EEG signal compression based on classified signature and envelope vector sets
    (Wiley, 2009-03) Gürkan, Hakan; Güz, Ümit; Yarman, Bekir Sıddık Binboğa
    In this paper, a novel method to compress electroencephalogram (EEG) signal is proposed. The proposed method is based on the generation process of the classified signature and envelope vector sets (CSEVS), which employs an effective k-means clustering algorithm. It is assumed that both the transmitter and the receiver units have the same CSEVS. In this work, on a frame basis, EEG signals are modeled by multiplying only three factors called as classified signature vector, classified envelope vector, and gain coefficient (GC), respectively. In other words, every frame of an EEG signal is represented by two indices R and K of CSEVS and the GC. EEG signals are reconstructed frame by frame using these numbers in the receiver unit by employing the CSEVS. The proposed method is evaluated by using some evaluation metrics that are commonly used in this area such as root-mean-square error, percentage root-mean-square difference, and measuring with visual inspection. The performance of the proposed method is also compared with the other methods. It is observed that the proposed method achieves high compression ratios with low-level reconstruction error while preserving diagnostic information in the reconstructed EEG signal.
  • Yayın
    Generalized frames in the space of strong limit power functions
    (Springer Basel AG, 2013-02) Ünalmış Uzun, Banu
    By using the existence of a larger orthonormal basis, the space of strong limit power functions is extended. We use the windowed Fourier transform and wavelet transform to analyze strong limit power signals and we construct generalized frame decompositions using the discretized versions of these transforms.
  • Yayın
    FCC-HH: The hadron collider: future circular collider conceptual design report volume 3
    (Springer Heidelberg, 2019-07-01) Bayındır, Cihan; Abada, Asmaa; Abbrescia, Marcello; AbdusSalam, Shehu S.
    In response to the 2013 Update of the European Strategy for Particle Physics (EPPSU), the Future Circular Collider (FCC) study was launched as a world-wide international collaboration hosted by CERN. The FCC study covered an energy-frontier hadron collider (FCC-hh), a highest-luminosity high-energy lepton collider (FCC-ee), the corresponding 100km tunnel infrastructure, as well as the physics opportunities of these two colliders, and a high-energy LHC, based on FCC-hh technology. This document constitutes the third volume of the FCC Conceptual Design Report, devoted to the hadron collider FCC-hh. It summarizes the FCC-hh physics discovery opportunities, presents the FCC-hh accelerator design, performance reach, and staged operation plan, discusses the underlying technologies, the civil engineering and technical infrastructure, and also sketches a possible implementation. Combining ingredients from the Large Hadron Collider (LHC), the high-luminosity LHC upgrade and adding novel technologies and approaches, the FCC-hh design aims at significantly extending the energy frontier to 100TeV. Its unprecedented centre of-mass collision energy will make the FCC-hh a unique instrument to explore physics beyond the Standard Model, offering great direct sensitivity to new physics and discoveries.
  • Yayın
    Reductions of topologically massive gravity I: Hamiltonian analysis of second order degenerate Lagrangians
    (Amer Inst Physics, 2018-01) Uçgun, Filiz Çağatay; Esen, Oğul; Gümral, Hasan
    We present Skinner-Rusk and Hamiltonian formalisms of second order degenerate Clement and Sarioglu-Tekin Lagrangians. The Dirac-Bergmann constraint algorithm is employed to obtain Hamiltonian realizations of Lagrangian theories. The Gotay-Nester-Hinds algorithm is used to investigate Skinner-Rusk formalisms of these systems.
  • Yayın
    Synthesis and liquid crystalline behavior of random copolymer of poly(ethylene oxide) macromonomer and liquid crystalline monomer by the photon transmission technique
    (Taylor & Francis Inc, 2005-12) Yıldız, Sevtap; Yılmaz, Faruk; Özbek, Haluk; Pekcan, Mehmet Önder; Ito, Koichi; Yağcı, Yusuf
    Random copolymers of poly(ethylene oxide) macromonomer with p-vinylbenzyl end-functional group (PEOVB) and liquid crystalline monomer, namely 6-(4-cyanobiphenyl-4'-oxy)hexyl acrylate (COA), were prepared by conventional free radical polymerization. A living anionic polymerization technique was employed for the synthesis of PEO macromonomers bearing p-vinylbenzyl moiety at one end. The photon transmission method was also applied to study the phase transitions of COA monomer and its random copolymer with PEO. It was found that, for both samples, the nematic-smectic A transition is continuous, but the critical fluctuation regions do not allow to obtain 3D XY values. Instead, we have obtained the values close to mean field regime. Scaling of thermal hystersis for random copolymer sample near the nematic-isotropic transition was studied as well. Thermal hysteresis loops were produced under linearly varying temperature. It was shown that the areas of the hysteresis loops scale with the temperature scanning rate with an exponent being equal to 0.614 which is in good agreement with the field-theoretical value.
  • Yayın
    An inverse source problem connected with thermoacoustic imaging in multi-layer planar medium
    (Springer, 2019-02-20) Yücel, Hazel; Ünalmış Uzun, Banu
    We derived analytical forward and inverse solution of thermoacoustic wave equation for nonhomogeneous medium. We modelled the nonhomogeneous medium as a multi-layer planar medium and defined initial conditions, continuity conditions on the layer boundaries and radiation conditions at infinity assuming the source distribution existing in all layers. These solutions of thermoacoustic wave equation are based on the method of Green’s functions for layered planar media. For qualitative testing and comparison of the point-spread functions associated with the homogeneous and layered solutions, we performed numerical simulations. Our simulation results showed that the conventional inverse solution based on homogeneous medium assumption, as expected, produced incorrect locations of point sources, whereas our inverse solution involving the multi-layer planar medium produced point sources at the correct source locations. Also, we examined whether the performance of our layered inverse solution is sensitive to medium parameters used as priority information in the measured data. Our inverse solutions based on multi-layer planar media are applicable for cross-sectional two-dimensional imaging of abdominal structure and the organs such as breast and skin.
  • Yayın
    A note on the amplitude modulation of symmetric regularized long-wave equation with quartic nonlinearity
    (Springer, 2012-12) Demiray, Hilmi
    We study the amplitude modulation of a symmetric regularized long-wave equation with quartic nonlinearity through the use of the reductive perturbation method by introducing a new set of slow variables. The nonlinear Schrodinger (NLS) equation with seventh order nonlinearity is obtained as the evolution equation for the lowest order term in the perturbation expansion. It is also shown that the NLS equation with seventh order nonlinearity assumes an envelope type of solitary wave solution.
  • Yayın
    Harmonic function for which the second dilatation is ?-spiral
    (Springer International Publishing AG, 2012) Aydoğan, Seher Melike; Duman, Emel Yavuz; Polatoğlu, Yaşar; Kahramaner, Yasemin
    Let f = h + (g) over bar be a harmonic function in the unit disc . We will give some properties of f under the condition the second dilatation is alpha-spiral.
  • Yayın
    A note on the exact travelling wave solution to the KdV-Burgers equation
    (Elsevier Science, 2003-10) Demiray, Hilmi
    In the present note, by use of the hyperbolic tangent method, a progressive wave solution to the Korteweg-de Vries-Burgers (KdVB) equation is presented. The solution we introduced here is less restrictive and comprises some solutions existing in the current literature (see [Wave Motion 11 (1989) 559; Wave Motion 14 (1991) 369]).