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1.
The purpose of this study was to examine CHO ingestion on a cognitive task using a field-simulated time-trial (TT) under hypoxia in well-trained triathletes. Ten male triathletes (age: 22.1 ± 1.1 years; VO2max: 59.4 ± 1.4 ml/kg/min) participated in this double-blind/crossover/counter-balanced design study. Participants completed 3 TT trials: 1) normoxic placebo (NPLA; FiO2 = 20.9%), 2) hypoxic placebo (HPLA; FiO2 = 16.3%), and 3) hypoxic CHO (HCHO; 6% CHO provided as 2 ml/kg/15 min; FiO2 = 16.3%). During the TT, physiological responses (SpO2, HR, RPE, and blood glucose/lactate), cognitive performance, and cerebral haemodynamics were measured. Hypoxia reduced TT performance by ~3.5–4% (p < 0.05), but CHO did not affect TT performance under hypoxia. For the cognitive task, CHO slightly preserved exercise-induced cognitive reaction speed but did not affect response accuracy during hypoxic exercise. However, CHO did not preserve the decreased Hb-Diff (cerebral blood flow, CBF) and increased HHb in the prefrontal lobe (p < 0.05) during hypoxic exercise, and CHO failed to preserve hypoxia-suppressed prefrontal CBF and tissue oxygen saturation. In conclusion, the present study demonstrates that CHO is effective in sustaining reaction speed for a cognitive task but not promoting TT performance during hypoxic exercise, which would be important for strategy-/decision-making when athletes compete at moderate high-altitude.  相似文献   
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In this paper, a modified adaptive neural network for the compensation of deadzone is described, and simulated on a hydraulic positioning system, in which the dynamic model is separated into a series of connection of a nonlinear (deadzone) subsystem and a linear plant. The proposed approach uses two neural networks. One is the radial basis function (RBF) neural network, which is used for identifying parameters of deadzone. Based on the penalty function used in optimization theory, a multi-objective cost function with constraint is adopted to provide the best deadzone approximation. The result is used to train the other neural network for the inverse compensation of deadzone. The RBF neural network also generates the parameters of the linear plant for the design of an adaptive controller. A convergence analysis for the network training process is also presented.  相似文献   
4.
This paper presents a newly developed digital redesign control scheme with a weighted switching strategy and output-reference tracking, for a cascaded analog system with state saturation and external loads. The proposed method improves the generally poor transition response and output deviation caused by state-saturation constraint and external loads. It replaces an existing or theoretically well-designed analog controller with state saturation, by a digital controller with almost identical performance.  相似文献   
5.
The main purpose of this study was to investigate Taiwanese high school students’ multi-dimensional self-efficacy and its sources in the domain of science. Two instruments, Sources of Science Learning Self-Efficacy (SSLSE) and Science Learning Self-Efficacy (SLSE), were used. By means of correlation and regression analyses, the relationships between students’ science learning self-efficacy and the sources of their science learning self-efficacy were examined. The findings revealed that the four sources of the students’ self-efficacy were found to play significant roles in their science learning self-efficacy. By and large, Mastery Experience and Vicarious Experience were found to be the two salient influencing sources. Several gender differences were also revealed. For example, the female students regarded Social Persuasion as the most influential source in the “Science Communication” dimension, while the male students considered Vicarious Experience as the main efficacy source. Physiological and Affective States, in particular, was a crucial antecedent of the female students’ various SLSE dimensions, including “Conceptual Understanding,” “Higher-Order Cognitive Skills,” and “Science Communication.” In addition, the variations between male and female students’ responses to both instruments were also unraveled. The results suggest that, first, the male students perceived themselves as having more mastery experience, vicarious experience and social persuasion than their female counterparts. Meanwhile, the female students experienced more negative emotional arousal than the male students. Additionally, the male students were more self-efficacious than the females in the five SLSE dimensions of “Conceptual Understanding,” “Higher-Order Cognitive Skills,” “Practical Work,” “Everyday Application,” and “Science Communication.”  相似文献   
6.
The current study examined how parents’ cultural socialization efforts contribute to adolescents’ family obligation values and behaviors and how these processes may depend upon the relational climate at home. Utilizing survey and daily diary methodologies, 428 Mexican‐American adolescents (50% males; Mage = 15 years) and their parents (83% mothers; Mage = 42 years) participated in the study. Adolescents reported on their family obligation values and engagement in family assistance tasks across 14 days. Parents reported on their cultural socialization practices. Results indicated that parental cultural socialization was associated with adolescents’ family obligation values and behaviors when parent–child relationships were low in conflict and high in support. Findings suggest that the transmission of cultural values and practices is best facilitated through positive parent–child relationships.  相似文献   
7.
Many education institutions and teachers are recognizing and applying online learning and related educational technologies to help students achieve satisfactory learning performance. Due to the free entertainment on the Internet that may distract students’ attention from online courses and with the purpose of developing students’ teamwork abilities, the author in this study adopted team-based learning (TBL) and co-regulated learning (CRL) to develop students’ involvement in a blended computing course. The subjects in this study were 111 first-year students from three classes taking a compulsory course titled ‘Applied information technology: data processing’. The first group (G1, which received online TBL and CRL) and the second group (G2, which received online TBL only) were the experimental groups. The last group (CG), which received the traditional teaching method in a blended learning environment, served as the control group. The results in this study indicate that students who receive the online TBL have significantly higher involvement than those without. However, the online CRL does not contribute to better development of students’ involvement in the implementation of TBL. The insights for teachers who plan to adopt e-learning, and the reasons for the ineffectiveness of CRL, are discussed in this study.  相似文献   
8.
Abstract

This article aims to develop a comprehensive understanding of changing cultural norms that have enabled and constrained women’s sport activities. It aims moreover, to analyse the changing nature of women’s sport activities in Taiwan. I want to show that what men can do, what women can do – and what I want to, what I can, and what I will do. I also address how I became interested in sports history and the pursuits I have made in that field.  相似文献   
9.
Although most ACL injury prevention programmes encourage greater hip and knee flexion during landing, it remains unknown how this technique influences tibiofemoral joint forces. We examined whether a landing strategy utilising greater hip and knee flexion decreases tibiofemoral anterior shear and compression. Twelve healthy women (25.9 ± 3.5 years) performed a drop-jump task before and after a training session (10–15 min) that emphasised greater hip and knee flexion. Peak tibiofemoral anterior shear and compressive forces were calculated using an electromyography (EMG)-driven knee model that incorporated joint kinematics, EMG and participant-specific muscle volumes and patella tendon orientation measured using magnetic resonance imaging (MRI). Participants demonstrated a decrease in peak anterior tibial shear forces (11.1 ± 3.3 vs. 9.6 ± 2.7 N · kg?1; P = 0.008) and peak tibiofemoral compressive forces (68.4 ± 7.6 vs. 62.0 ± 5.5 N · kg?1; P = 0.015) post-training. The decreased peak anterior tibial shear was accompanied by a decrease in the quadriceps anterior shear force, while the decreased peak compressive force was accompanied by decreased ground reaction force and hamstring forces. Our data provide justification for injury prevention programmes that encourage greater hip and knee flexion during landing to reduce tibiofemoral joint loading.  相似文献   
10.
Internet‐based science learning has been advocated by many science educators for more than a decade. This review examines relevant research on this topic. Sixty‐five papers are included in the review. The review consists of the following two major categories: (1) the role of demographics and learners' characteristics in Internet‐based science learning, such as demographic background, prior knowledge, and self‐efficacy; and (2) the learning outcomes derived from Internet‐based science learning, such as attitude, motivation, conceptual understanding, and conceptual change. Some important conclusions are drawn from the review. For example, Internet‐based science learning is equally favorable, or in some cases more so, to learning for female students compared to male students. The learner's control is essential for enhancing students' attitudes and motivation toward learning in Internet‐based science learning environments. Nevertheless, appropriate guidance from teachers, moderators, or the Internet‐based learning environment itself is still quite crucial in Internet‐based science learning. Recommendations for future research related to the effects of Internet‐based science learning on students' metacognitive reflections, epistemological development, and worldviews are suggested.  相似文献   
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