Key somatic variables associated with,and differences between the 4 swimming strokes     

Alan M. Nevill  Yassine Negra  Tony D. Myers  Senda Sammoud  Helmi Chaabene 《Journal of sports sciences》2020,38(7):787-794

ABSTRACT

This study identified key somatic and demographic characteristics that benefit all swimmers and, at the same time, identified further characteristics that benefit only specific swimming strokes. Three hundred sixty-three competitive-level swimmers (male [n = 202]; female [n = 161]) participated in the study. We adopted a multiplicative, allometric regression model to identify the key characteristics associated with 100 m swimming speeds (controlling for age). The model was refined using backward elimination. Characteristics that benefited some but not all strokes were identified by introducing stroke-by-predictor variable interactions. The regression analysis revealed 7 “common” characteristics that benefited all swimmers suggesting that all swimmers benefit from having less body fat, broad shoulders and hips, a greater arm span (but shorter lower arms) and greater forearm girths with smaller relaxed arm girths. The 4 stroke-specific characteristics reveal that backstroke swimmers benefit from longer backs, a finding that can be likened to boats with longer hulls also travel faster through the water. Other stroke-by-predictor variable interactions (taken together) identified that butterfly swimmers are characterized by greater muscularity in the lower legs. These results highlight the importance of considering somatic and demographic characteristics of young swimmers for talent identification purposes (i.e., to ensure that swimmers realize their most appropriate strokes).  相似文献   

Dialectics of design: how ideas of ‘good design’ change     

《普罗米修斯》2012,30(1):29-39

This paper advances a first‐pass theory of change in the styling of objects of domestic utility. It is based on the idea that the expressive potential of design for the maker, the user and the designer exists in tension with other desirable properties of the designed artefact. Respectively these are mass availability, conformity to professionally‐defined ideas of good taste, and the demands of function and marketability. The theory is illustrated by reference to the emergence and subsequent dilution of three design movements; Arts and Crafts, Art Nouveau and certain versions of Modernism.  相似文献   

科技期刊论文图片的鉴定     

潘华 《编辑学报》2016,28(4):338-340

对科技期刊论文中图片的抄袭和篡改问题进行研究,从图片属性分析、源码分析和利用JPEGsnoop软件鉴定等方面,提出图片篡改的识别方法,为科技期刊在论文收录时,能准确判断图片是否被刻意篡改或抄袭,以打击学术不端行为.  相似文献   

利用引文确定领域关键文献的方法探析     

张云  华薇娜  袁顺波 《图书情报工作》2016,60(1):66

[目的/意义]确定基于引用关系提取关键文献时各种方法的优缺点、适用场合,从而使用户快速捕捉领域重要文献,掌握领域概貌。[方法/过程]基于文献引用关系,从文献被引频次、文献引用网络、文献共被引网络3个角度,结合HistCite、CiteSpace等软件探讨领域关键文献的识别方法,通过同源数据的实际验证,对不同方法进行判别比较。[结果/结论]基于被引频次的方法更适合选择特定领域中哪些文献对总体文献的科学进步产生重大影响角度提取关键文献,对应的关键文献集合呈现非常分散的特性;基于引用网络的方法更适合从特定领域研究动态提取发展过程中的关键文献,对应的关键文献集合呈现非常明显的集中特性;基于共被引网络的方法更适合从特定领域研究基础角度提取关键文献,对应的关键文献集合呈现较强的集中性,且能发现原始采集中未发现的大量关键文献。  相似文献   

规则认同、个体学习与转型期社区共享资源合作治理     

夏茂森  方鸣  江玲玲 《安徽师范大学学报(人文社会科学版)》2019,47(4):141-149

本文尝试将规则认同偏好、个体信念学习调整纳入多人自愿合作的分析框架,并构建了基于转型期社区共享资源合作治理的博弈理论模型,考察规则认同偏好异质性、个体学习在社区共享资源合作治理中的作用机理,并进行了相应的仿真模拟分析。研究表明,规则认同偏好的异质性影响个体的策略选择调整,进而影响社区共享资源的合作治理,尤其是当政府在部分或完全退出社区共享资源治理情况下,对避免或弥补转型期社区共享资源“治理真空”具有重要的影响作用。此外,自发治理的规则认同程度与合作治理的形成概率成正比,且规则偏好在一定程度上可以缓解共享资源合作治理的成本问题。但随着治理成本的不断上升,规则认同与合作治理两者之间的条件比率呈递减趋势。  相似文献   

Self-categorization process in sport: An examination of the “Linsanity” phenomenon in Taiwan     

《Sport Management Review》2016,19(4):431-440

The “Linsanity” phenomenon attracted an increase in attention toward the National Basketball Association (NBA) for a short period of time. Drawing on self-categorization theory to elucidate current literature on team identification, this research proposed a conceptual model delineating the social psychological process for international consumers during the phenomenon. Using an online survey with a convenience sample in Taiwan, structural equation modeling, including confirmatory factor analysis (CFA) and path analysis, validated the conceptual model and confirmed the relationships between constructs in the model. Results indicated that Taiwanese identification positively influenced player identification, while player identification mediated the relationship between Taiwanese identification and team identification. Consequently, team identification positively influenced NBA involvement. The research findings together contribute to explicating the mechanism behind consumers’ self-categorization process during the “Linsanity” phenomenon while offering implications for international sport marketing. The research concludes with suggestions for future research.  相似文献   

Discriminating talent-identified junior Australian football players using a video decision-making task     

Carl T. Woods  Annette J. Raynor  Lyndell Bruce  Zane McDonald 《Journal of sports sciences》2016,34(4):342-347

This study examined if a video decision-making task could discriminate talent-identified junior Australian football players from their non-talent-identified counterparts. Participants were recruited from the 2013 under 18 (U18) West Australian Football League competition and classified into two groups: talent-identified (State U18 Academy representatives; n = 25; 17.8 ± 0.5 years) and non-talent-identified (non-State U18 Academy selection; n = 25; 17.3 ± 0.6 years). Participants completed a video decision-making task consisting of 26 clips sourced from the Australian Football League game-day footage, recording responses on a sheet provided. A score of “1” was given for correct and “0” for incorrect responses, with the participants total score used as the criterion value. One-way analysis of variance tested the main effect of “status” on the task criterion, whilst a bootstrapped receiver operating characteristic (ROC) curve assessed the discriminant ability of the task. An area under the curve (AUC) of 1 (100%) represented perfect discrimination. Between-group differences were evident (P < 0.05) and the ROC curve was maximised with a score of 15.5/26 (60%) (AUC = 89.0%), correctly classifying 92% and 76% of the talent-identified and non-talent-identified participants, respectively. Future research should investigate the mechanisms leading to the superior decision-making observed in the talent-identified group.  相似文献   

Positional group significantly influences the offensive and defensive skill involvements of junior representative rugby league players during match play     

Kyle J. M. Bennett  Job Fransen  Brendan R. Scott  Colin E. Sanctuary  Tim J. Gabbett  Ben J. Dascombe 《Journal of sports sciences》2016,34(16):1542-1546

This study examined the skill involvements of three positional groups across a junior representative rugby league season. Data were collected from 45 rugby league players (mean ± SD; age = 16.5 ± 1.0 years) currently participating in the Harold Matthews and SG Ball Cup. Players were subdivided into hit-up forwards, adjustables and outside backs. The frequency (n · min^?1) of offensive, defensive and overall involvements was coded for each group using a notation system and a practical coach skill analysis tool. Multivariate analysis of variance (MANOVA) revealed a significant effect of playing position on skill involvements (F = 9.06; P < 0.001; ES = 0.41). Hit-up forwards performed a significantly greater frequency of offensive (0.31 ± 0.10), defensive (0.42 ± 0.15) and overall involvements (0.74 ± 0.19) when compared to adjustables (0.20 ± 0.08, 0.28 ± 0.08 and 0.52 ± 0.15, respectively) and outside backs (0.20 ± 0.12, 0.11 ± 0.07 and ± 0.31 ± 0.17, respectively). Further, adjustables performed a significantly greater number of defensive (0.28 ± 0.08) and overall involvements (0.52 ± 0.15) when compared to outside backs (0.11 ± 0.07 and 0.31 ± 0.17, respectively). The findings of this study suggest that it is important to consider a junior player’s positional group when analysing their skill involvements. Information gained from this study could assist in the design of specific training methodologies for junior rugby league players in high-level talent development programmes.  相似文献   

Sprint and jump performances do not determine the promotion to professional elite soccer in Spain, 1994–2012     

Raul Martinez-Santos  Daniel Castillo 《Journal of sports sciences》2016,34(24):2279-2285

ABSTRACT

The aims of this study are (a) to describe the evolution of neuromuscular performance over an 18 year period within a Spanish elite reserve team; (b) to check if there were any relation between the playing position and sprint and jump performances and (c) to look into the alleged impact of this factor on the top playing level attained by the soccer players. We considered the physical tests (5 m and 15 m sprint times and countermovement jump (CMJ) height) made by 235 players enrolled in the reserve team of the Club from 1994 to 2012 and the highest competitive-level they achieved: Spanish first (n = 39) and second divisions (n = 36) and semi-professional (n = 160). Furthermore, the players were classified according to their playing positions. The main findings were a very-likely/most-likely lower neuromuscular performance (ES = 0.48–0.68, small to moderate) in the last six-season term (2006–2012) than in the first term (1994–2000); possibly/very-likely lower performances in sprinting and CMJ (ES = 0.22–0.55, small) by central defenders (CDs) and midfielders than by other playing positions; very-likely better performances in sprinting and jumping by first and second divisions central defenders than by semi-professional central defenders (ES = 0.90–1.02, moderate). Sprint and jump performances are not a relevant physical parameter to promote to the top level of soccer in Spain except for one in six of the playing positions: CDs.  相似文献   

立足地域特色与资源优势优化创新选题思路--新疆图书选题存在的问题与发展对策     

姚永春  宋文静 《出版科学》2016,24(3):47-51

分析新疆出版业图书选题存在的问题,指出新疆具有浓郁的地域特色和丰富的民族文化资源,图书选题策划应当充分发挥地域特色和资源优势,着力策划民族语言类、非物质遗产类、“一带一路”类选题,繁荣区域文化,打造有新疆特色的民族出版业。  相似文献