Sport-based physical activity intervention on body weight in children and adolescents: a meta-analysis     

Kyungun Kim  Gina Ok  Soeun Jeon  Minsoo Kang 《Journal of sports sciences》2017,35(4):369-376

Controversial results reported in past research pertaining to the effectiveness of sport-based physical activity interventions on weight loss. The purpose of this study was to assess the impact of sport-based physical activity intervention on body weight in children and adolescents using a meta-analysis. Academic Search Complete, Education Source, ERIC, Medline, ProQuest, PsycINFO and SportDiscus databases were searched from January 2000 to April 2015. Eighteen studies met following inclusion criteria: sport-based intervention studies; subjects aged 6–18 years; reported body weight; published in peer-reviewed journals written in English. The mean intervention duration was 17.72 weeks. The overall effect size (ES) was 0.52 (Cohen’s d (ES) = 0.52, 95% CI = 0.08, 0.95, P = 0.021), using a random effects model. Moderator analyses results showed that the Q statistic for the sport type (individual sport or team sport, Qbetween (Q_b) = 14.52, df = 1, P = 0.001) and diet control (Qbetween (Q_b) = 8.85, df = 1, P = 0.001), explained the heterogeneity of ESs. Our study showed that there was a moderate overall effect of sport-based physical activity intervention on body weight reduction. The team sport type (ES = 1.05, 95% CI = 0.44, 1.66) and diet control group (ES = 0.84, 95% CI = 0.26, 1.41) appeared to be more effective in reducing body weight.  相似文献   

Evidence for data missing at random in youth physical activity monitoring research     

P. F. Saint-Maurice  Y. Kim  G. J. Welk 《Journal of sports sciences》2017,35(5):484-490

This study examined whether or not activity monitor data collected as part of a typical 7-day physical activity (PA) measurement protocol can be expected to be missing at random. A total of 315 participants (9–18 years) each wore a SenseWear Armband monitor for 7 consecutive days. Participants were classified as “compliant” (86 boys and 124 girls) if they had recorded accelerometer data during 70% or more of the predefined awake time (7 AM–10 PM) on four different days; and “non-compliant” (44 boys and 51 girls) when not meeting these criteria. Linear mixed models were used to examine differences in energy expenditure (EE) levels by compliance across 10 different time periods. The results indicated that non-compliant girls were older (13.4 ± 2.9 vs. 12.2 ± 2.5) and taller (156.8 ± 10.3 vs. 152.8 ± 11.3) than their same gender compliant peers (P < .05). Comparisons of EE rates at segmented portions of the day revealed no differences between compliant and non-compliant groups (P ≥ .05). Differences in EE ranged from ?0.32 kcal · kg^?1 · h^?1 (before school time) to 0.62 kcal · kg^?1 · h^?1 (physical education class) in boys and ?0.39 kcal · kg^?1 · h^?1 (transportation from school) to 0.37 kcal · kg^?1 · hour^?1 (recess) in girls. The results showed that compliant and non-compliant individuals differed in a few demographic characteristics but exhibited similar activity patterns. This suggests that data were considered to be missing at random, but additional work is needed to confirm this observation in a representative sample of children using other types of activity monitors and protocols.  相似文献   

The forgotten promise of e-government maturity: Assessing responsiveness in the digital public sector     

Kim Normann Andersen  Rony Medaglia  Ravi Vatrapu  Helle Zinner Henriksen  Robin GauldAuthor vitae 《Government Information Quarterly》2011,28(4):439-445

Assessing e-government responsiveness is one of the major gaps in the currently dominant e-government maturity models. While we have a relatively large pool of models focusing on technological and organizational integration from a supply side perspective, measures of responsiveness of e-government systems from a user perspective are still lacking. Replicating a study from New Zealand and Australia, this study explores the response time and quality of e-mail response in Danish local and central governments (N = 175). Despite that Denmark is high ranking in international benchmark studies, we find that one third of central government agencies did not respond at all, and close to 80% of the ministries provided none or incomplete answers. Local government responds faster and provides answers that are more complete and accurate than those provided by central government. Implications for e-government are discussed.  相似文献   

Nonquadratic stabilization conditions for nonhomogeneous Markovian jump fuzzy systems with higher-level operation modes     

Sung Hyun Kim 《Journal of The Franklin Institute》2021,358(2):1553-1577

This paper is concerned with the problem of designing a dissipative control for generalized nonhomogeneous Markovian jump fuzzy systems (MJFSs) that can cover both piecewise-homogeneous MJFSs and nonhomogeneous MJFSs through the use of dual modes, i.e., plant and higher-level modes. Based on a dual-mode-dependent fuzzy control law within a nonparallel distributed compensation (non-PDC) scheme, the nonquadratic stabilization conditions are first formulated in terms of multi-parameterized linear matrix inequalities (M-PLMIs), and then be transformed into a finite set of solvable LMIs without reducing M-PLMIs to PLMIs. Further, since the proposed relaxation technique can address the transition probabilities of plant and higher-level modes at once, the characteristics on mutual dependence between dual modes are fully incorporated into the nonquadratic stabilization conditions. Two illustrative examples are given to show the validity of the proposed approach.  相似文献   

Merging relative sensing networks: A stability margin perspective     

Vahid Hamdipoor  Yoonsoo Kim 《Journal of The Franklin Institute》2021,358(6):3127-3149

This study considers merging dynamical networks (relative sensing networks in this paper) in terms of a stability margin criterion. The main motivation of this consideration is that merging can cause a significant drop in the stability margin of merged network with respect to the original networks initially with ample stability margins. In this paper, various types of network merging (i.e. undirected/directed homogeneous/heterogeneous dynamical network merging via one-way/two-way links) are analysed to show their effects on the stability margin. In particular, it is shown that (1) merging with one-way links yields the stability margin less than the original networks’; (2) merging undirected homogeneous networks with two-way links results in a stability margin being at least a quantity solely characterized by the positive realness (PRness) of SISO (Single-Input-Single-Output) local dynamics; (3) the quantity depends both on the PRness of SISO local dynamics and the eigenvalues of Laplacian matrix, in case of merging directed homogeneous networks with two-way links; (4) two-way merging using multiple nodes may allow for a large increase in the stability margin; and (5) merging heterogeneous networks may be simply treated as merging homogeneous networks by exploiting the design of link dynamics. Several numerical results are presented to show their consistency with the performed analysis.  相似文献   

Kicking modality during erratic-dynamic and static condition effects the muscular co-activation of attacker     

Tae-Whan Kim  Sang-Cheol Lee  Se-Kee Kil  Sung-Chul Kang  Young-Tae Lim 《Journal of sports sciences》2017,35(9):835-841

The purpose of the study was to investigate the effect of different kicking modality, i.e., erratic-dynamic target (EDT) versus static target (ST) on the performance of the roundhouse kick in two groups of taekwondo athletes of different skill level. Three-dimensional analysis and surface electromyography (SEMG) analysis were performed on 12 (Group A: six sub-elite, Group B: six elite) athletes to investigate muscle co-activation pattern under two conditions, i.e., EDT versus ST. In the results, the muscle recruitment ratio of the agonistic muscles was higher for Group A, whereas Group B had higher recruitment ratio for antagonist muscles. Overall, the co-activation index (CI) of hip joints appeared higher in the extensors for Group A, whereas higher CI was observed in flexor muscles for Group B with comparatively higher CI during EDT condition than ST condition. Higher value of CI was observed in flexor muscles of the knee joints among Group A during EDT conditions, in contrast, higher CI in the extensor muscles was observed among Group B during ST conditions. In conclusion, the study confirmed that erratic-dynamic movements of target could change the movement coordination pattern to maintain the joint stability of participants.  相似文献   

EUROPEAN DISSERTATION SUMMARIES     

Mijung Kim  Aik‐Ling Tan 《International Journal of Science Education》2013,35(4):465-472

To alleviate teachers’ reluctance toward practical work, there has been much discussion on teachers’ pedagogical content knowledge, teaching materials, and failsafe strategies for practical work. Despite these efforts, practical work is still regarded as a challenging task for many elementary science teachers. To understand the complexity of teachers’ conflicts in practical work, this study examines teachers’ ideas about teaching and learning that influence teachers’ decision‐making and action on teaching practical work. More important than knowing technical–rational aspects of practical work is to understand the internal contradictions that teachers have to resolve within themselves regarding their capabilities and beliefs about science teaching and practical work. Using stories and experiences of 38 third‐year university students in a science method course in Korea, we seek to understand the conflicts and negotiations that they experience as they make decisions regarding practical work throughout their course. Reflective writings and group discussions on their lived experiences and concerns were used to probe participants’ ideas on teaching using practical work. From written and verbal data, themes were saturated in terms of the aspects which could (dis)encourage their practice. Results suggest that there are multifactorial challenges in pre‐service teachers’ understandings and concerns in practical work. Besides time, materials, and curriculum, pedagogical assumptions and values also compositely challenge the minds of teachers. As the pre‐service elementary teachers negotiated within themselves the importance of science in classroom and social levels, the question is raised about their identities as pre‐service elementary teachers to appreciate the balance between science teaching and practical work.  相似文献   

New Vision and Challenges in Inquiry-Based Curriculum Change in Singapore     

Mijung Kim  Frederick Toralballa Talaue 《International Journal of Science Education》2013,35(2):289-311

A new primary science syllabus with strong inquiry focus has been implemented in Singapore since 2008. In this study, we attempted to understand how teachers experience the emphasis of inquiry-based curriculum under the current educational conditions that is routined and highly teacher fronted. We invited 50 pre-service and 41 in-service teachers to participate in survey questionnaires and narratives, reflective writings, and group discussions related to science inquiry which formed our data corpus. Data analysis in the form of thematic coding was carried out using NVivo8, with over 80% inter-rater coding agreement level. Three key aspects of teachers’ perceptions of science inquiry were revealed: (1) teachers’ responsibilities as facilitators, (2) privileging content knowledge rather than process skills, and (3) pressure of assessment systems in current educational contexts. These understandings bring out conflicts of inquiry teaching between teacher- and student-centredness, content and process, and curriculum and assessment. Based on these teachers’ perceptions and dilemmas of inquiry science teaching, the visions and challenges of inquiry science curriculum change against assessment requirements are discussed.  相似文献   

Now and forever: portraits of qualitative research in Korea     

Young Chun Kim  Jeasik Cho 《International journal of qualitative studies in education》2013,26(3):355-377

  相似文献   

Implications for improving access and outcomes for individuals with disabilities in postsecondary distance education     

Weol Soon Kim‐Rupnow  Peter W. Dowrick  Laure S. Burke 《The American journal of distance education》2013,27(1):25-40

  相似文献