Kazan Meslek Yüksekokulu / Kazan Vocational School
Permanent URI for this collectionhttps://hdl.handle.net/11727/2077
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Item Covering the More Visible Region by Electrochemical Copolymerization of Carbazole and Benzothiadiazole Based Donor-Acceptor Type Monomers(2019) Cansu-Ergun, Emine Gul; 0000-0002-3941-4345; I-7385-2017An electrochromic copolymer film of 2-(3,3-dihexyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepin-6-yl)-7-(3,3-dihexyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepin-8-yl)-9H-carbazole (M1) and 4,7-bis(thiophen-2-yl)benzo[c][1,2,5]thiadiazole (M2) was prepared via electrochemical technique. The copolymerization was performed with one to one monomer feed ratio. Electrochemical and optical properties of the resulting copolymer film (P3) and the homopolymer films of M1 and M2 (P1 and P2) were investigated by using cyclic voltammetry and UV-Vis spectrometry techniques, and the corresponding results were compared. Incorporation of M1 and M2 into copolymer matrix was clearly observed on the resulting cyclic voltammograms and UV-Vis spectra. P3 covered the visible regions coming from both P1 and P2, and exhibited a neutral state darker color than those of homopolymers. P3 film was found to have a multichromic behavior, appearing as brown in its neutral state while changing its color upon oxidation to dark-gray (at about 0.3 V), to blue (at about 0.6 V) and finally to grayish cyan (beyond 0.9 V), with a corresponding optical band gap of 1.65 eV.Item Pulse frequency fluctuations of magnetars(2019) Cerri-Serim, D.; Serim, M. M.; Sahiner, S.; Inam, S.C.; Baykal, A.; 0000-0003-0820-9186Using RXTE, Chandra, XMM-Newton and Swift observations, we construct the power spectra and torque noise strengths of magnetars for the first time. For some of the sources, on time-scales of months to years, we measure strong red noise that might be a consequence of their outbursts. We compare the noise strengths of magnetars with those of radio pulsars by investigating the possible correlations of noise strength with spin-down rate, magnetic field and age. Using these correlations, we find that the noise strengths of magnetars obey similar trends as radio pulsars. However, we do not find any correlation between noise strength and X-ray luminosity, a correlation that has been seen in accretion-powered pulsars. Our findings suggest that the noise behaviour of magnetars resembles that of radio pulsars, but magnetars possess higher noise levels likely because of their stronger magnetic fields.Item NUMERICAL STABILITY OF RBF APPROXIMATION FOR UNSTEADY MHD FLOW EQUATIONS(2019) Gurbuz, Merve; Tezer-Sezgin, M.In this study, the radial basis function (RBF) approximation is applied for solving the unsteady fluid flow and magnetohydrodynamic (MHD) convection flow problems with the use of explicit Euler time discretization and relaxation parameters to accelerate the convergence. The stability analysis is also carried out in terms of the spectral radius of related RBF discretized coefficient matrices. The optimal choices of the time increment, relaxation parameters and physical problem parameters are found for achieving stable solutions. It is observed that the maximum eigenvalues of the coefficient matrices decrease with an increase in the time increment when the relaxation parameters are decreasing. Although the time derivative is discretized using explicit Euler method, one does not need to use small time increment for obtaining stable results. The flow, isotherms and pressure behaviors are simulated at steady-state for several values of problem parameters using time increment and relaxation parameters which lead to stable solutions.Item A Deep LSTM Approach for Activity Recognition(2019) Guney, Selda; Erdas, Cagatay Berke; 0000-0002-0573-1326; 0000-0003-3467-9923; AAC-7404-2020Since 1990s, activity recognition effectual field in machine learning literature. Most of studies that relevant activity recognition, use feature extraction method to achieve higher classification performance. Moreover, these studies mostly use traditional machine learning algorithms for classification. In this paper, we focus on a deep (Long Short Term Memory) LSTM neural network for feature free classification of seven daily activities by using raw data that collected from three-dimensional accelerometer. Based on the results, the proposed deep LSTM approach can classify raw data with high performance. The results show that the proposed deep LSTM approach achieved 91.34, 96.91, 88.78, 87.58 as percent classification performance in terms of accuracy, sensitivity, specificity, F-measure respectively.Item Calibration transfer in temperature modulated gas sensor arrays(2016) Fernandez, L.; Güney, S.; Gutierrez-Galvez, A.; Marco, S.Shifts in working temperature are an important issue that prevents the successful transfer of calibration models from one chemical instrument to another. This effect is of special relevance when working with gas sensor arrays modulated in temperature. In this paper, we study the use of multivariate techniques to transfer the calibration model from a temperature modulated gas sensor array to another when a global change of temperature occurs. To do so, we built 12 identical master sensor arrays composed of three different types of commercial Figaro sensors and acquired a dataset of sensor responses to three pure substances (ethanol, acetone and butanone) dosed at 7 concentrations. The master arrays are then shifted in temperature (from -50 to 50 degrees C, Delta T = 10 degrees C) and considered as slave arrays. Data correction is performed for an increasing number of transfer samples with 4 different calibration transfer techniques: Direct Standardization, Piece-wise Direct Standardization, Orthogonal Signal Correction and Generalized Least Squares Weighting. In order to evaluate the performance of the calibration transfer, we compare the Root Mean Square Error of Prediction (RMSEP) of master and slave arrays, for each instrument correction. Best results are obtained from Piece-wise Direct standardization, which exhibits the lower RMSEP values after correction for the smaller number of transfer samples. (C) 2016 Elsevier B.V. All rights reserved.Item Causative Mutations and Mechanism of Androgenetic Hydatidiform Moles(2018) Nguyen, N.M.P.; Ge, Z.-J.; Reddy, R.; Fahiminiya, S.; Sauthier, P.; Bagga, R.; Sahin, F.I.; Mahadevan, S.f; Osmond, M.; Breguet, M.; Rahimi, K.; Lapensee, L.; Hovanes, K.; Srinivasan, R.; Van den Veyver, I.B.; Sahoo, T.; Ao, A.; Majewski, J.; Taketo, T.; Sim, R.; 0000-0001-7308-9673; 30388401; AAC-7232-2020Androgenetic complete hydatidiform moles are human pregnancies with no embryos and affect 1 in every 1,400 pregnancies. They have mostly androgenetic monospermic genomes with all the chromosomes originating from a haploid sperm and no maternal chromosomes. Androgenetic complete hydatidiform moles were described in 1977, but how they occur has remained an open question. We identified bi-allelic deleterious mutations in MEI1, TOP6BL/C11orf80, and REC114, with roles in meiotic double-strand breaks formation in women with recurrent androgenetic complete hydatidiform moles. We investigated the occurrence of androgenesis in Mei1-deficient female mice and discovered that 8% of their oocytes lose all their chromosomes by extruding them with the spindles into the first polar body. We demonstrate that Mei1−/− oocytes are capable of fertilization and 5% produce androgenetic zygotes. Thus, we uncover a meiotic abnormality in mammals and a mechanism for the genesis of androgenetic zygotes that is the extrusion of all maternal chromosomes and their spindles into the first polar body. © 2018 American Society of Human Genetics