2,455 research outputs found
Students' perception of their ideal teacher: influence of students' academic motivation
This study aims to examine whether students’ level of motivation to learn in a college influences how they
perceive an ideal teacher. One hundred and twenty-two students participated in this study. Participants
completed a questionnaire on their motivation and ideal teacher’s traits. Results support the view that
students are generally extrinsically motivated. Students’ academic motivation corresponded to their
perception of ideal teacher’s behaviour. This study recommends that teachers use different instructional
strategies to motivate both intrinsic and extrinsic students
Stabilization and current-induced motion of antiskyrmion in the presence of anisotropic Dzyaloshinskii-Moriya interaction
Topological defects in magnetism have attracted great attention due to
fundamental research interests and potential novel spintronics applications.
Rich examples of topological defects can be found in nanoscale non-uniform spin
textures, such as monopoles, domain walls, vortices, and skyrmions. Recently,
skyrmions stabilized by the Dzyaloshinskii-Moriya interaction have been studied
extensively. However, the stabilization of antiskyrmions is less
straightforward. Here, using numerical simulations we demonstrate that
antiskyrmions can be a stable spin configuration in the presence of anisotropic
Dzyaloshinskii-Moriya interaction. We find current-driven antiskyrmion motion
that has a transverse component, namely antiskyrmion Hall effect. The
antiskyrmion gyroconstant is opposite to that for skyrmion, which allows the
current-driven propagation of coupled skyrmion-antiskyrmion pairs without
apparent skyrmion Hall effect. The antiskyrmion Hall angle strongly depends on
the current direction, and a zero antiskyrmion Hall angle can be achieved at a
critic current direction. These results open up possibilities to tailor the
spin topology in nanoscale magnetism, which may be useful in the emerging field
of skyrmionics.Comment: 31 pages, 6 figures, to appear in Physical Review
Recommended from our members
Multistaged discharge constructing heterostructure with enhanced solid-solution behavior for long-life lithium-oxygen batteries.
Inferior charge transport in insulating and bulk discharge products is one of the main factors resulting in poor cycling stability of lithium-oxygen batteries with high overpotential and large capacity decay. Here we report a two-step oxygen reduction approach by pre-depositing a potassium carbonate layer on the cathode surface in a potassium-oxygen battery to direct the growth of defective film-like discharge products in the successive cycling of lithium-oxygen batteries. The formation of defective film with improved charge transport and large contact area with a catalyst plays a critical role in the facile decomposition of discharge products and the sustained stability of the battery. Multistaged discharge constructing lithium peroxide-based heterostructure with band discontinuities and a relatively low lithium diffusion barrier may be responsible for the growth of defective film-like discharge products. This strategy offers a promising route for future development of cathode catalysts that can be used to extend the cycling life of lithium-oxygen batteries
BTS: Bifold Teacher-Student in Semi-Supervised Learning for Indoor Two-Room Presence Detection Under Time-Varying CSI
In recent years, indoor human presence detection based on supervised learning
(SL) and channel state information (CSI) has attracted much attention. However,
the existing studies that rely on spatial information of CSI are susceptible to
environmental changes, such as object movement, atmospheric factors, and
machine rebooting, which degrade prediction accuracy. Moreover, SL-based
methods require time-consuming labeling for retraining models. Therefore, it is
imperative to design a continuously monitored model life-cycle using a
semi-supervised learning (SSL) based scheme. In this paper, we conceive a
bifold teacher-student (BTS) learning approach for presence detection systems
that combines SSL by utilizing partially labeled and unlabeled datasets. The
proposed primal-dual teacher-student network intelligently learns spatial and
temporal features from labeled and unlabeled CSI. Additionally, the enhanced
penalized loss function leverages entropy and distance measures to distinguish
drifted data, i.e., features of new datasets affected by time-varying effects
and altered from the original distribution. The experimental results
demonstrate that the proposed BTS system sustains asymptotic accuracy after
retraining the model with unlabeled data. Furthermore, the label-free BTS
outperforms existing SSL-based models in terms of the highest detection
accuracy while achieving the asymptotic performance of SL-based methods
- …