1,390 research outputs found

    Toward better intelligent learning (iLearning) performance:what makes iLearning work for students in a university setting?

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    We explored the critical factors associated with iLearning that impact students’ learning performance and identified the factors with a notable influence to help managers in higher education institutions increase the effectiveness of iLearning for students. We initially synthesised 4 main dimensions (including 26 criteria): performance expectancy, lecturers’ influence, quality of service, and personal innovativeness. Subsequently, we conducted surveys in two stages. First, by studying a group of students with experience using iLearning at Taiwanese universities, we extracted 5 critical dimensions (including 18 criteria) through a factor analysis. Second, by studying a group of senior educators and practitioners in Taiwan, we prioritised the dimensions and criteria through the analytic hierarchy process (AHP). We found that performance expectancy is the top critical dimension, and the top five critical criteria pertain to enhancing the learning performance, increasing the learning participation, altering learning habits, ensuring access at all times, and enabling prompt use of learning resources. Moreover, we recommend several suggestions for the relevant managers to enhance the students’ iLearning performance

    U(1) CS Theory vs SL(2) CS Formulation: Boundary Theory and Wilson Line

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    We first derive the boundary theory from the U(1) Chern-Simons theory. We then introduce the Wilson line and discuss the effective action on an nn-sheet manifold from the back-reaction of the Wilson line. The reason is that the U(1) Chern-Simons theory can provide an exact effective action when introducing the Wilson line. This study cannot be done in the SL(2) Chern-Simons formulation of pure AdS3_3 Einstein gravity theory. It is known that the expectation value of the Wilson line in the pure AdS3_3 Einstein gravity is equivalent to entanglement entropy in the boundary theory up to classical gravity. We show that the boundary theory of the U(1) Chern-Simons theory deviates by a self-interaction term from the boundary theory of the AdS3_3 Einstein gravity theory. It provides a convenient path to the building of "minimum surface=entanglement entropy" in the SL(2) Chern-Simons formulation. We also discuss the Hayward term in the SL(2) Chern-Simons formulation to compare with the Wilson line approach. To reproduce the entanglement entropy for a single interval at the classical level, we introduce two wedges under a regularization scheme. We propose the quantum generalization by combining the bulk and Hayward terms. The quantum correction of the partition function vanishes. In the end, we exactly calculate the entanglement entropy for a single interval. The pure AdS3_3 Einstein gravity theory shows a shift of central charge by 26 at the one-loop level. The U(1) Chern-Simons theory does not have such a shift from the quantum effect, and the result is the same in the weak gravitational constant limit. The non-vanishing quantum correction shows the naive quantum generalization of the Hayward term is incorrect.Comment: 39 pages, 2 figure

    A New Virtual Oscillator Control Without Third-Harmonics Injection For DC/AC Inverter

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    Finite Control Set Model Predictive Control for an LCL-Filtered Grid-Tied Inverter with Full Status Estimations under Unbalanced Grid Voltage

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    This paper proposes a novel finite control set model predictive control (FCS-MPC) strategy with merely grid-injected current sensors for an inductance-capacitance-inductance (LCL)-filtered grid-tied inverter, which can obtain a sinusoidal grid-injected current whether three-phase grid voltages are balanced or not. Compared with the conventional FCS-MPC method, four compositions are added in the proposed FCS-MPC algorithm, where the grid voltage observer (GVO) and Luenberger observer are combined together to achieve full status estimations (including grid voltage, capacitor voltage, inverter-side current, and grid-injected current), while the sequence extractor and the reference generator are applied to eliminate the double frequency ripples of the active or reactive power, or the negative sequence component (NSC) of the grid-injected current caused by the unbalanced grid voltage. Simulation model and experimental platform are established to verify the effectiveness of the proposed FCS-MPC strategy, with full status estimations under both balanced and unbalanced grid voltage conditions

    Robust Control Parameters Design of PBC Controller for LCL-Filtered Grid-Tied Inverter

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    Clinical significance of erythromycin-resistant Campylobacter jejuni in children

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    Campylobacter has been recognized as the common cause of bacterial gastroenteritis in many countries. Increasing erythromycin resistance in Campylobacter jejuni infection is noted recently, but severe case was rarely reported. In this study, we aimed to clarify the clinical significance of the resistant strain of C jejuni in children. We reviewed the charts of children who were diagnosed with C jejuni enteritis in our hospital from January 2000 to December 2005, including 326 patients (117 males and 209 females). All the cases had positive stool culture. We divided them into two groups, the sensitive group (a total of 306 cases) and resistant group (a total of 20 cases), according to the drug sensitivity. We analyzed the clinical manifestations and laboratory data between the two groups. The mean age was 3.79±3.24 years in the sensitive group and 3.03±2.84 years in the resistant group. There was no significant difference between the two groups in clinical presentations and laboratory examinations. No mortality was found, and one case was initially presented with colonic perforation. This report demonstrates that infection by erythromycin-resistant strains of C jejuni has no clinical significance in children, despite the probably increased emergence of erythromycin resistance
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