300 research outputs found

    Exploring self-regulation through learning navigation pathways in online learning during the pandemic

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    Abstract. Online learning has shown significant growth as a powerful alternative method to deliver learning through the pandemic situation. In the meantime, many studies have been attempting to investigate how to provide education within online platforms effectively; however, a few have examined how students regulate their learning during online courses. Through the lens of self-regulated learning theory and Zimmerman’s cyclical model (2000), the present study examines how successful students and less successful students regulate their learning in hypermedia contexts. Moreover, the research aims to explore self-regulatory behaviors via the learning pathways between successful students and less successful students in a learning management system. The process-oriented method was applied to investigate the student’s learning paths from the log data collected. The coding was done based on a new coding scheme created through the lens of self-regulated learning theories, in which half of the events were assigned with self-regulatory activities due to the lack of theoretical explanation. The frequency analysis and process mining analysis of coded learning events were generated to examine the differences in self-regulated learning between successful and less successful students. The results indicate how successful and less successful students regulate differently in their learning navigation. For educators, the study provides insights to better design online learning courses and suggests self-regulatory strategies to support students in hypermedia contexts

    Comparison of optimal designs of steel portal frames including topological asymmetry considering rolled, fabricated and tapered sections

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    A structural design optimisation has been carried out to allow for asymmetry and fully tapered portal frames. The additional weight of an asymmetric structural shape was found to be on average 5 to 13% with additional photovoltaic (PV) loading having a negligible effect on the optimum design. It was also shown that fabricated and tapered frames achieved an average percentage weight reduction of 9% and 11%, respectively, as compared to comparable hot-rolled steel frames. When the deflection limits recommended by the Steel Construction Institute were used, frames were shown to be deflection controlled with industrial limits yielding up to 40% saving

    Detection of lithium in nearby young late-M dwarfs

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    Late M-type dwarfs in the solar neighborhood include a mixture of very low-mass stars and brown dwarfs which is difficult to disentangle due to the lack of constraints on their age such as trigonometric parallax, lithium detection and space velocity. We search for young brown dwarf candidates among a sample of 28 nearby late-M dwarfs with spectral types between M5.0 and M9.0, and we also search for debris disks around three of them. Based on theoretical models, we used the color I−JI-J, the JJ-band absolute magnitude and the detection of the Li I 6708 A˚\AA doublet line as a strong constraint to estimate masses and ages of our targets. For the search of debris disks, we observed three targets at submillimeter wavelength of 850 μ\mum. We report here the first clear detections of lithium absorption in four targets and a marginal detection in one target. Our mass estimates indicate that two of them are young brown dwarfs, two are young brown dwarf candidates and one is a young very low-mass star. The closest young field brown dwarf in our sample at only ∼\sim15 pc is an excellent benchmark for further studying physical properties of brown dwarfs in the range 100−-150 Myr. We did not detect any debris disks around three late-M dwarfs, and we estimated upper limits to the dust mass of debris disks around them.Comment: 10 pages, 5 figures, accepted for publication in Astronomy and Astrophysic

    One-loop expressions for h→llˉγh\rightarrow l\bar{l}\gamma in Higgs extensions of the Standard Model

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    A systematic study of one-loop contributions to the decay channels h→llˉγh\rightarrow l\bar{l}\gamma with l=νe,μ,τ,e,μl=\nu_{e,\mu, \tau}, e, \mu, performed in Higgs extended versions of the Standard Model, is presented in the 't Hooft-Veltman gauge. Analytic formulas for one-loop form factors are expressed in terms of the logarithm and di-logarithmic functions. As a result, these form factors can be reduced to those relating to the loop-induced decay processes h→γγ,Zγh\rightarrow \gamma\gamma, Z\gamma, confirming not only previous results using different approaches but also close relations between the three kinds of the loop-induced Higgs decay rates. For phenomenological study, we focus on the two observables, namely the enhancement factors defined as ratios of the decay rates calculated between the Higgs extended versions and the standard model, and the forward-backward asymmetries of fermions, which can be used to search for Higgs extensions of the SM. We show that direct effects of mixing between neutral Higgs bosons and indirect contributions of charged Higg boson exchanges can be probed at future colliders.Comment: 39 pages, 9 Figures, 11 Tables of dat

    Identification of nonlinear heat transfer laws from boundary observations

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    We consider the problem of identifying a nonlinear heat transfer law at the boundary, or of the temperature-dependent heat transfer coefficient in a parabolic equation from boundary observations. As a practical example, this model applies to the heat transfer coefficient that describes the intensity of heat exchange between a hot wire and the cooling water in which it is placed. We reformulate the inverse problem as a variational one which aims to minimize a misfit functional and prove that it has a solution. We provide a gradient formula for the misfit functional and then use some iterative methods for solving the variational problem. Thorough investigations are made with respect to several initial guesses and amounts of noise in the input data. Numerical results show that the methods are robust, stable and accurate

    Magnetic and Magnetotransport Properties of La0.7ca0.3mn1-x(zn,cu)xo3

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    Magnetic and magnetotransport properties of two perovskite manganite samples of La0.7Ca0.3Mn0.9Zn0.1O3 and La0.7Ca0.3Mn0.95Cu0.05O3 prepared by conventional solid-state reaction have been studied in detail. Experimental results revealed that the temperature dependences of magnetization and resistance varied strongly around the phase-transition temperature. Maximum magnetoresistance (MR) values of La0.7Ca0.3Mn0.9Zn0.1O3 and La0.7Ca0.3Mn0.95Cu0.05O3 under an applied field of 400 Oe were about 21.4 % and 11.0 %, respectively. The maximum magnetic-entropy change (ΔSM) was 2.73 J/kg.K for La0.7Ca0.3Mn0.9Zn0.1O3, and 3.34 J/kg.K for La0.7Ca0.3Mn0.95Cu0.05O3 when the applied field was 45 kOe. Both the MR and ΔSM values obtained from two samples were smaller than those of the parent compound La0.7Ca0.3MnO3. This was due to the change in the Mn3+/Mn4+ ratio caused by Zn and Cu dopants, which led to a change in the type of the ferromagneticparamagnetic phase transition
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