257 research outputs found
Effectiveness of textually-enhanced captions on Chinese high-school EFL learnersâ incidental vocabulary learning
This study employed mixed-methods approach to investigate the impact of textually-enhanced captions on EFL learnersâ incidental vocabulary gains and learnersâ perceptions of the captioning usefulness in a multi-modal learning environment. 133 Chinese EFL high school learners of the low-intermediate level were randomly assigned to English captions with highlighted target words and L1 gloss (ECL1), Chinese and English captions (CEC), Chinese and English captions with highlighted target words (CECGW), and no captions (NC). Our quasi-experimental findings did not detect any significant differences among the caption types on vocabulary form recognition while ECL1 was found the most effective in meaning recall and recognition. Captioning types and learnersâ language proficiency exerted medium-to-large effects on meaning recall and meaning recognition. Our qualitative data suggested the participants generally viewed captioned videos positively, with variability in perceptions of concurrent presentation of information. The saliency of L1 gloss could direct the viewersâ attention to the semantic features of a word and reinforce sound-form-meaning connections. Videos lacking L1 glosses of target words had relatively little effect on learnersâ vocabulary learning while more textual inputs might not necessarily result in vocabulary gains. Pedagogical implications are proposed for teachersâ adoption of L1 in captioned videos to enhance learnersâ learning effectiveness.Este estudio investigĂł el impacto y las percepciones de los estudiantes de los subtĂtulos mejorados textualmente en las ganancias incidentales de vocabulario de los estudiantes de inglĂ©s como lengua extranjera en un entorno de aprendizaje multimodal. 133 estudiantes chinos de inglĂ©s como lengua extranjera de nivel intermedio bajo fueron asignados aleatoriamente a subtĂtulos en inglĂ©s con palabras objetivo resaltadas y brillo L1 (ECL1), subtĂtulos en chino e inglĂ©s (CEC), subtĂtulos en chino e inglĂ©s con palabras objetivo resaltadas (CECGW), y sin subtĂtulos (NC). Nuestros hallazgos cuasi-experimentales no detectaron diferencias significativas entre los tipos de subtĂtulos en el reconocimiento de formas de vocabulario, mientras que ECL1 resultĂł ser el mĂĄs efectivo para recordar y reconocer significados. Nuestros datos cualitativos sugirieron que los participantes generalmente veĂan los videos subtitulados de manera positiva, con variabilidad en las percepciones de la presentaciĂłn simultĂĄnea de informaciĂłn. La prominencia del brillo L1 podrĂa dirigir la atenciĂłn de los espectadores a las palabras objetivo y reforzar las conexiones de la forma del sonido y el significado
Primary clear cell sarcoma of humerus: case report
We report a case of primary clear cell sarcoma occurring in the humerus. A 20 year old girl was referred to our hospital two years ago with painless swelling of the soft tissue surrounding the proximal right humerus. The conventional radiographic image showed an ill-defined, aggressive, osteolytic lesion associated with a partial cortical defect of the proximal right humerus. Magnetic resonance imaging found an irregularly shaped extraosseous mass extending from the proximal shaft of the right humerus, penetrating through the destroyed bone and invading the biceps brachii. After preoperative chemotherapy, a total tumor resection, internal fixation and bone cement implantation were performed. Histological studies of the resected tumor found that fibrous septa divided into well-defined nests and polygonal and fusiform cells with clear cytoplasm. Immunohistochemical studies demonstrated strong positive cytoplasmic staining with S-100 and scattered positivity with HMB-45. These findings led to a final, definitive diagnosis of clear cell sarcoma of the humerus. After routine postoperative chemotherapy, a 2-year follow-up showed no metastasis. Our findings in this report point out that primary clear cell sarcoma can originate from within the humerus and that limb salvage surgery can obtain a good result
Robust Geometric Formation Control of Multiple Autonomous
©2013 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.Presented at the American Control Conference (ACC 2013), 17-19 June 2013, Washington, D.C.This paper develops a robust controller for autonomous
underwater vehicles with bounded time delays, so
that the AUVs form and keep a desired formation shape and
track a desired trajectory. We use a six-degree-of-freedom
dynamic model for each AUV to describe its motions in the
three-dimensional space. We design an orientation controller
based on feedback linearization, so that the orientation of
each AUV converges to its desired value. We derive formation
dynamics of AUVs and decouple the dynamics into a formation
shape and a formation center, using the Jacobi transform. We
treat couplings in the formation dynamics as perturbations and
design a robust formation-keeping controller to tolerate both
the perturbations and the time delays. We demonstrate the
effectiveness of our controller in simulations
Novelty seeking and mental health in Chinese university students before, during, and after the COVID-19 pandemic lockdown: a longitudinal study
COVID-19 has created significant concern surrounding the impact of pandemic lockdown on mental health. While the pandemic lockdown can be distressing, times of crisis can also provide people with the opportunity to think divergently and explore different activities. Novelty seeking, where individuals explore novel and unfamiliarly stimuli and environments, may enhance the creativity of individuals to solve problems in a way that allows them to adjust their emotional responses to stressful situations. This study employs a longitudinal design to investigate changes in novelty seeking and mental health outcomes (namely, stress, anxiety, and depression) before, during, and after COVID-19 pandemic lockdown, among a group of students (final N = 173; Mage = 19.81; SDage = 0.98; 135 females and 38 males) from a university in southeast China. Participants were surveyed at three points: November, 2019 (prior to the COVID-19 pandemic); between February and March, 2020 (during the peak of the pandemic and intense lockdown in China); and between May and June, 2020 (after lockdown had been lifted in China). Cross-sectionally, correlation analysis indicated that greater novelty seeking was associated with lower levels of stress, anxiety, and depression at all three time points. Univariate latent curve modelling (LCM) indicated a growth trajectory in which novelty seeking increased over time and then remained high during the post-lockdown period. Stress, anxiety, and depression all showed V-shaped growth trajectories in which these variables decreased during lockdown, before increasing in the post-lockdown period. Multivariate LCM indicated the growth trajectory for novelty seeking was associated with the growth trajectories for stress, anxiety, and depression. This suggests that the observed decreases in stress, anxiety, and depression during the lockdown period may be attributable to the sampleâs observed increase in novelty seeking. These findings are valuable in that they challenge the notion that lockdown measures are inherently detrimental to mental health. The findings indicate the important role of novelty seeking in responding to crises. It may be possible for future public health measures to incorporate the promotion of novelty seeking to help individualsâ respond to stressful situations and maintain good mental health in the face of crises
Mental health of Chinese people during the COVID-19 pandemic: associations with infection severity of region of residence and filial piety
This study aims to investigate mental health among Chinese people living in areas with differing levels of infection severity during the COVID-19 outbreak. It also assesses the association between reciprocal and authoritarian filial piety and mental health in times of crises. A sample of 1,201 Chinese participants was surveyed between April and June 2020. Wuhan city (where 23.4% of participants resided), Hubei province outside Wuhan (13.4% of participants), and elsewhere in China (63.1% of participants) were categorized into high, moderate, and low infection severity areas, respectively. The Depression, Anxiety, and Stress Scaleâs severity cut-points were used to categorize participants. In the overall sample, 20.9, 34.2, and 29.0% of the participants showed elevated (mild to extremely severe) levels of stress, anxiety, and depression. Those in the highest infection severity group were significantly more likely to be categorized as having elevated levels of stress, anxiety, and depression. General linear modeling was performed on a composite mental distress variable (taking into account stress, anxiety, and depression scores). This model indicated that, even after adjusting for group differences in age, gender, education, and filial piety, the high infection severity group displayed more mental distress than the low infection severity groups. The model also found reciprocal filial piety to have a negative association with mental distress. Conversely, authoritarian filial piety was found to be unrelated to mental distress when controlling for the other variables in the model. No evidence was found for an interaction between either authoritarian or reciprocal filial piety and infection severity, which suggests that the negative association observed between reciprocal filial piety and mental distress was relatively consistent across the three infection severity groups. The findings suggest that future public health programs may integrate the promotion of filial piety as a strategy to help Chinese people maintain good mental health in the face of pandemic crises
Performance Comparison of Wavefront-Sensorless Adaptive Optics Systems by Using of the Focal Plane
The correction capability and the convergence speed of the wavefront-sensorless adaptive optics (AO) system are compared based on two different system control algorithms, which both use the information of focal plane. The first algorithm is designed through the linear relationship between the second moment of the aberration gradients and the masked far-field intensity distribution and the second is stochastic parallel gradient descent (SPGD), which is the most commonly used algorithm in wavefront-sensorless AO systems. A wavefront-sensorless AO model is established with a 61-element deformable mirror (DM) and a CCD. Performance of the two control algorithms is investigated and compared through correcting different wavefront aberrations. Results show that the correction ability of AO system based on the proposed control algorithm is obviously better than that of AO system based on SPGD algorithm when the wavefront aberrations increase. The time needed by the proposed control algorithm is much less than that of SPGD when the AO system achieves similar correction results. Additionally, the convergence speed of the proposed control algorithm is independent of the turbulence strength while the number of intensity measurements needed by SPGD increases as the turbulence strength magnifies
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