176 research outputs found

    Evaluation of social personalized adaptive E-Learning environments : end-user point of view

    Get PDF
    The use of adaptations, along with the social affordances of collaboration and networking, carries a great potential for improving e-learning experiences. However, the review of the previous work indicates current e-learning systems have only marginally explored the integration of social features and adaptation techniques. The overall aim of this research, therefore, is to address this gap by evaluating a system developed to foster social personalized adaptive e-learning experiences. We have developed our first prototype system, Topolor, based on the concepts of Adaptive Educational Hypermedia and Social E-Learning. We have also conducted an experimental case study for the evaluation of the prototype system from different perspectives. The results show a considerably high satisfaction of the end users. This paper reports the evaluation results from end user point of view, and generalizes our method to a component-based evaluation framework

    Assocative Photoproduction of Roper Resonance and ω\omega-Meson

    Full text link
    Associative photoproduction of ω\omega-meson and N(1440)N^{*}(1440) on nucleons, γ+Nω+N(1440)\gamma+N\to\omega+N^{*}(1440), in the near threshold region is investigated in a framework employing effective Lagrangians. Besides π\pi-exchange in t-channel, baryon exchanges, i.e. N- and NN^{*}-exchanges, in the s- and u-channels are also taken into account in calculations of differential cross-section and beam asymmetry. Important inputs of this model are the vector and tensor coupling constants of ωNN(1440)\omega NN^{*}(1440)-vertex, which are assumed to be equal to the values of these couplings for ωNN\omega NN vertex. Using our previous estimation of ωNN\omega NN coupling constants obtained from a fit to available experimental data on photoproduction of ω\omega meson in the near threshold region, we produce the necessary numerical predictions for different observables in γ+Nω+N(1440)\gamma+N\to\omega+N^{*}(1440). Numerical results shows that at low |t| dominant contribution comes from t-channel π\pi-exchange while effects of nucleon and N(1440)N^{*}(1440) pole terms can be seen at large t|t|. Our predictions for the differential cross section and beam asymmetry for the processes γ+Nω+N(1440)\gamma+N\to\omega+N^{*}(1440), where N is proton and neutron at Eγ=2.5E_{\gamma}=2.5 GeV are presented with zero width approximation and also with the inclusion of width effects of N(1440)N^{*}(1440).Comment: 20 Pages, Latex, 6 ps figure

    End-to-End Learning of Video Super-Resolution with Motion Compensation

    Full text link
    Learning approaches have shown great success in the task of super-resolving an image given a low resolution input. Video super-resolution aims for exploiting additionally the information from multiple images. Typically, the images are related via optical flow and consecutive image warping. In this paper, we provide an end-to-end video super-resolution network that, in contrast to previous works, includes the estimation of optical flow in the overall network architecture. We analyze the usage of optical flow for video super-resolution and find that common off-the-shelf image warping does not allow video super-resolution to benefit much from optical flow. We rather propose an operation for motion compensation that performs warping from low to high resolution directly. We show that with this network configuration, video super-resolution can benefit from optical flow and we obtain state-of-the-art results on the popular test sets. We also show that the processing of whole images rather than independent patches is responsible for a large increase in accuracy.Comment: Accepted to GCPR201

    The Effect of the Pairing Interaction on the Energies of Isobar Analog Resonances in 112124^{112-124}Sb and Isospin Admixture in 100124^{100-124}Sn Isotopes

    Full text link
    In the present study, the effect of the pairing interaction and the isovector correlation between nucleons on the properties of the isobar analog resonances (IAR) in 112124^{112-124}Sb isotopes and the isospin admixture in 100124^{100-124}Sn isotopes is investigated within the framework of the quasiparticle random phase approximation (QRPA). The form of the interaction strength parameter is related to the shell model potential by restoring the isotopic invariance of the nuclear part of the total Hamiltonian. In this respect, the isospin admixtures in the 100124^{100-124}Sn isotopes are calculated, and the dependence of the differential cross section and the volume integral JFJ_{F} for the Sn(3^{3}He,t)Sb reactions at E(3^{3}He)=200=200 MeV occurring by the excitation of IAR on mass number A is examined. Our results show that the calculated value for the isospin mixing in the 100^{100}Sn isotope is in good agreement with Colo et al.'s estimates (45(4-5%), and the obtained values for the volume integral change within the error range of the value reported by Fujiwara et al. (53±\pm5 MeV fm3^{3}). Moreover, it is concluded that although the differential cross section of the isobar analog resonance for the (3^{3}He,t) reactions is not sensitive to pairing correlations between nucleons, a considerable effect on the isospin admixtures in NZN\approx Z isotopes can be seen with the presence of these correlations.Comment: 16 pages, 5 EPS figures and 2 tables, Late

    Vector meson production and nucleon resonance analysis in a coupled-channel approach for energies m_N < sqrt(s) < 2 GeV II: photon-induced results

    Full text link
    We present a nucleon resonance analysis by simultaneously considering all pion- and photon-induced experimental data on the final states gamma N, pi N, 2 pi N, eta N, K Lambda, K Sigma, and omega N for energies from the nucleon mass up to sqrt(s) = 2 GeV. In this analysis we find strong evidence for the resonances P_{31}(1750), P_{13}(1900), P_{33}(1920), and D_{13}(1950). The omega N production mechanism is dominated by large P_{11}(1710) and P_{13}(1900) contributions. In this second part we present the results on the photoproduction reactions and the electromagnetic properties of the resonances. The inclusion of all important final states up to sqrt(s) = 2 GeV allows for estimates on the importance of the individual states for the GDH sum rule.Comment: 41 pages, 26 figures, discussion extended, typos corrected, references updated, to appear in Phys. Rev.

    Visualizing Escherichia coli Sub-Cellular Structure Using Sparse Deconvolution Spatial Light Interference Tomography

    Get PDF
    Studying the 3D sub-cellular structure of living cells is essential to our understanding of biological function. However, tomographic imaging of live cells is challenging mainly because they are transparent, i.e., weakly scattering structures. Therefore, this type of imaging has been implemented largely using fluorescence techniques. While confocal fluorescence imaging is a common approach to achieve sectioning, it requires fluorescence probes that are often harmful to the living specimen. On the other hand, by using the intrinsic contrast of the structures it is possible to study living cells in a non-invasive manner. One method that provides high-resolution quantitative information about nanoscale structures is a broadband interferometric technique known as Spatial Light Interference Microscopy (SLIM). In addition to rendering quantitative phase information, when combined with a high numerical aperture objective, SLIM also provides excellent depth sectioning capabilities. However, like in all linear optical systems, SLIM's resolution is limited by diffraction. Here we present a novel 3D field deconvolution algorithm that exploits the sparsity of phase images and renders images with resolution beyond the diffraction limit. We employ this label-free method, called deconvolution Spatial Light Interference Tomography (dSLIT), to visualize coiled sub-cellular structures in E. coli cells which are most likely the cytoskeletal MreB protein and the division site regulating MinCDE proteins. Previously these structures have only been observed using specialized strains and plasmids and fluorescence techniques. Our results indicate that dSLIT can be employed to study such structures in a practical and non-invasive manner

    Neoliberal anti-racism: Responding to ‘everywhere but different’ racism

    Full text link
    © 2016, © The Author(s) 2016. Racism cannot be treated as a spatially homogeneous phenomenon. This review reports on the merits of a localized approach to anti-racism, and delivers a frank assessment of the challenges faced when developing local responses to racism in a neoliberal era. Under neoliberalism, local actors are responsibilized, and for anti-racism this means action can potentially be closely aligned to local inflexions of racism. But localized responses to racism under neoliberalism are associated with deracialized and depoliticized policies on interethnic community relations. Neoliberal anti-racism promotes competition among local agencies rather than coalition building, and is associated with spatially uneven and non-strategic action
    corecore