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41.
The purpose of the study was to examine the effectiveness of the Iowa Chautauqua Professional Development Program in terms of changes in concept mastery, use of process skills, application of science concept and skills, student attitudes toward science, student creativity, and student perceptions regarding their science classrooms. Participants were 12 teachers who agreed to participate in an experimental study where an inquiry approach was utilized with one section and traditional strategies in another section. A total of 24 sections of students were enrolled in inquiry sections (365 students) and traditional sections (359 students). The data collected were analyzed using quantitative methods. The results are tabulated and contrasted for students enrolled in the two sections for each teacher. The results indicate that student use and understanding of science skills and concepts in the inquiry sections increased significantly more than they did for students enrolled in typical sections in terms of process skills, creativity skills, ability to apply science concepts, and the development of more positive attitudes. 相似文献
42.
Cagdas Hakan Aladag Erol Egrioglu Murat A. Basaran 《Journal of Computational and Applied Mathematics》2010,233(10):2683-2687
Although artificial neural networks (ANN) have been widely used in forecasting time series, the determination of the best model is still a problem that has been studied a lot. Various approaches available in the literature have been proposed in order to select the best model for forecasting in ANN in recent years. One of these approaches is to use a model selection strategy based on the weighted information criterion (WIC). WIC is calculated by summing weighted different selection criteria which measure the forecasting accuracy of an ANN model in different ways. In the calculation of WIC, the weights of different selection criteria are determined heuristically. In this study, these weights are calculated by using optimization in order to obtain a more consistent criterion. Four real time series are analyzed in order to show the efficiency of the improved WIC. When the weights are determined based on the optimization, it is obviously seen that the improved WIC produces better results. 相似文献
43.
Hakan Yeti?kin 《Applied mathematics and computation》2010,216(7):1896-1902
The existence and uniqueness for the solution of the problem of determining the v(x,t) potential in the Schrödinger equation from the measured final data ψ(x,T)=y(x) is investigated. For the objective functional , it is proven that the problem has at least one solution for α?0, and has a unique solution for α>0. The necessary condition for solvability the problem is stated as the variational principle. 相似文献
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45.
We study the accumulation of an elliptic fixed point of a real analytic Hamiltonian by quasi-periodic invariant tori. We show that a fixed point with Diophantine frequency vector ω 0 is always accumulated by invariant complex analytic KAM-tori. Indeed, the following alternative holds: If the Birkhoff normal form of the Hamiltonian at the invariant point satisfies a Rüssmann transversality condition, the fixed point is accumulated by real analytic KAM-tori which cover positive Lebesgue measure in the phase space (in this part it suffices to assume that ω 0 has rationally independent coordinates). If the Birkhoff normal form is degenerate, there exists an analytic subvariety of complex dimension at least d + 1 passing through 0 that is foliated by complex analytic KAM-tori with frequency ω 0. This is an extension of previous results obtained in [1] to the case of an elliptic fixed point. 相似文献
46.
The asymptotic iteration method is used to find exact and approximate solutions of Schrödinger’s equation for a number of one-dimensional trigonometric potentials (sine-squared, double-cosine, tangent-squared, and complex cotangent). Analytic and approximate solutions are obtained by first using a coordinate transformation to reduce the Schrödinger equation to a second-order differential equation with an appropriate form. The asymptotic iteration method is also employed indirectly to obtain the terms in perturbation expansions, both for the energies and for the corresponding eigenfunctions. 相似文献
47.
Selimefendigil Fatih Oztop Hakan F. Chamkha Ali J. 《Journal of Thermal Analysis and Calorimetry》2019,135(1):325-340
Journal of Thermal Analysis and Calorimetry - In this study, fluid flow and heat transfer in a vertical lid-driven CuO–water nanofluid filled square cavity with a flexible fin attached to its... 相似文献
48.
Hussain Shafqat Öztop Hakan F. Mehmood Khalid Ali Mohamed E. 《Journal of Thermal Analysis and Calorimetry》2019,137(1):289-306
Journal of Thermal Analysis and Calorimetry - In the present study, a computational work has been done to see the heat transfer, fluid flow and temperature distribution in a lid-driven cavity due... 相似文献
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50.
Kerim Serbest Hakan Kayi Mustafa Er Kemal Sancak smail Deirmenciolu 《Heteroatom Chemistry》2008,19(7):700-712
Four new mononuclear metal complexes with a mononucleating Schiff base ligand containing two thiadiazoles units have been synthesized. The ligand and metal complexes were characterized by elemental analyses, IR, 1H, and 13C NMR, UV–vis, ESR, electrospray ionization mass spectra, and magnetic susceptibility measurements. Electronic spectra, magnetic susceptibility measurement, and molecular modeling studies support octahedral geometry around the Ni(II), Cu(II), and Zn(II) ions. The magnetic properties were investigated, and ferromagnetic coupling is observed in Cu(II) and Ni(II) complexes. In addition, total energy and heat of formation calculated for conformers of the Schiff base ligand by the semiempirical AM1 calculations have shown that E,Z‐isomer of the ligand is more stable (about 5.3 kcal/mol) than E,E‐ and Z,Z‐isomers. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:700–712, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20496 相似文献