Arama Sonuçları
Listeleniyor 1 - 10 / 200
Yayın EEG signal compression based on classified signature and envelope vector sets(Wiley, 2009-03) Gürkan, Hakan; Güz, Ümit; Yarman, Bekir Sıddık BinboğaIn 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, BanuBy 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 New directions for women's political development in Turkey: Exploring the implications of the internet for Ka-der(IOS Press, 2014) Karakaya Polat, Rabia; Çağlı Kaynak, ElifUnderrepresentation of women in Turkish politics is well documented. This is evident in the numbers of women in key decision-making positions, including the Parliament. The role of women's NGOs is significant in educating, motivating and mobilizing women to participate in politics. These organizations increasingly use the Internet for mobilization, opinion formation, recruitment, networking, lobbying and fundraising. The paper explores the extent to which and the ways in which Ka-der as a WNGOs is affected by the Internet, both in terms of its structure and operation, including its relationships with members and adherents and in the way Ka-der communicates with external actors, such as similar organizations, potential members, politicians and the media. We argue that different functions of WNGOs are supported asymmetrically by the Internet. While the e-mail group is mostly used for internal purposes, the website and the use of social media serve to enhance links with the outside environment.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, YusufRandom 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 A note on the amplitude modulation of symmetric regularized long-wave equation with quartic nonlinearity(Springer, 2012-12) Demiray, HilmiWe 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, YaseminLet 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, HilmiIn 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]).Yayın The sectoral sweeper scheme for wireless sensor networks: Adaptive antenna array based sensor node management and location estimation(Kluwer Academic Publishers-Plenum Publishers, 2006-12) Erdoğan, Ayhan; Coşkun, Vedat; Kavak, AdnanWe introduce a novel sensor node management and location estimation method referred as sectoral sweeper (SS) scheme that uses an adaptive antenna array (AAA) at a central node in wireless sensor networks (WSNs). With the SS scheme, the central node can activate or deactivate the nodes in a desired region which is specified by beam direction and beam width of the transmit beam and also by minimum and maximum thresholds (R (min) and R (max)) for the received signal strength indicator (RSSI) of signals received by the nodes. In order to perform a specified task that is associated with a Task_id, two different beams are transmitted, which are task region beam and routing region beam to switch the nodes into active or routing modes. Since our scheme does not require any additional software or hardware for node management and location estimation in sensor nodes, the deficiencies of tiny sensors are effectively eliminated. The proposed scheme is shown to reduce the number of sensing nodes and the amount of data traffic in the network, thus leading to considerable savings in energy consumption and prolonged sensor lifetime.Yayın Dissipative dynamics and the statistics of energy states of a Hookean model for protein folding(Kluwer Academic Publishers-Plenum Publishers, 2000-07) Tüzel, Erkan; Erzan, AyşeA generic model of a random polypeptide chain, with discrete torsional degrees of freedom and Hookean spring connecting pails or hydrophobic residues, reproduces the energy probability distribution of real proteins over a very large range of energies. We show that this system with harmonic interactions, under dissipative dynamics driven by random noise, leads to a distribution of energy states obeying a modified one-dimensional Ornstein-Uhlenbeck process and giving rise Lo the so-called Wigner distribution. A tunably fine- or coarse-grained sampling of the energy landscape yields a family of distributions for the energies and energy spacings.Yayın A new late holocene eolianite record from Altinkum Beach, North Cyprus(Scientific technical research council Turkey-Tubitak, 2012-06) Erginal, Ahmet Evren; Güneç Kıyak, Nafiye; Ertek, Topçu AhmetIn this study, we investigated the main depositional characteristics and obtained Optically Stimulated Luminescence (OSL) ages of coastal eolianite on the north coast of Cyprus, where this occurrence had not previously been recorded. Based on EDX/SEM and XRD data and field observations, the studied eolianite that crops out between elevations of 1 m and 14 m a.s.l. is made up predominantly of quartz grains, most of which consist of medium- to fine-grained sand. The rock comprises aragonite, calcite and quartz with lesser amounts of bornite and hematite as accessory minerals. OSL ages indicated that the initial deposition of eolianite sands took place at 1.51 +/- 0.21 ka years ago.
