2017年世界男排联赛中国男排与对手比赛技术效果对比分析          下载免费PDF全文

陈贞祥  赵德峰  沈琼 《体育科研》2019,(2):97-108

通过对比分析在2017年世界男排联赛上中国男排与对手在比赛中的整体技术效果、3站比赛间中国男排自身的技术效果及各站对手的技术效果，得出在劳尔教练任期的第一次世界大赛中国男排技术效果上的优势与不足，为其日后训练比赛提供数据参考和建议。研究发现：中国男排在发球、一传和防守技术效果上显著差于对手，一攻和反攻技术效果略差于对手，仅拦网技术效果显著好于对手。发现中国男排存在如下问题：（1）发球技术能力与外教战术意图不匹配，且缺少沟通；（2）一传稳定性差，顶不住大力发球冲击成为被对手制约的短板，且一传的差距直接转化为一攻的差距表现出来；（3）二传传平拉开球速度不够快，导致战术进攻意图过于明显；（4）比赛中拦网技术存在补拦意识仍不够、移动跟不上、拦一点放弃了两点的不足；（5）防守队员预判能力不够，下蹲过浅造成移动慢，从而对拦起球的保护跟不上。此外，研究还就3站比赛进行分类对比分析，得出了相应结论与建议。  相似文献   

基于极化特征和纹理特征的PolSAR影像建筑物提取方法     

马肖肖  程博  刘岳明  崔师爱  梁琛彬 《中国科学院大学学报》2019,36(5):682-693

极化合成孔径雷达（PolSAR）以其多参数、多通道、多极化、信息记录更加完整等特点，在城市地物提取领域中发挥着重要作用，并已成为遥感影像研究领域的热点。选择覆盖苏州市的Radarsat2影像，利用极化非相干分解法和灰度共生矩阵法分别提取19种极化特征和8种纹理特征，通过分析建筑物、植被和水体的极化特征和纹理特征进行特征组合，结合主成分分析法（PCA）和支持向量机法（SVM）对城市建筑物进行提取，并定量评估精度。结果表明：基于极化特征的建筑物提取精度最高为92.4%；基于纹理特征的提取精度最高为88.9%；极化特征与纹理特征相结合可以提高精度，最高精度为93.7%；PCA特征融合算法具有较高的运算效率，同时提高了精度。  相似文献   

Where are all the males? Gender-specific typologies of childhood adversity based on a large community sample     

《Child abuse & neglect》2019

BackgroundMethodological issues have been identified when quantifying exposure to adversity and abuse. To address a single type may obscure covarying effects. To sum multiple exposures gives equal weight to each. Latent class analysis (LCA) addresses this by identifying homogenous subpopulations. Most studies using LCA have pooled gender data in spite of evidence that the nature and frequency of exposure differs by gender. Males report more interpersonal abuse, females report more of other exposures, particularly sexual.ObjectiveThis study aimed to identify if stratifying data by gender resulted in different profiles of adversity/abuseParticipants and setting: The National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) wave II, a large community-based survey, nationally representative of the US population.MethodThis study used 14 indicators of childhood adversity as the basis for LCA.ResultsThe number and nature of classes differed by gender. The best solution for females was 4-class: a low risk class; a class at higher risk of sexual abuse; a class at higher risk of physical abuse; a class at higher risk of combined physical and sexual abuse. The best solution for males had only 3-classes; a low risk class, a class at higher risk of sexual abuse; a class at higher risk of physical abuse. The combined dataset resulted in a solution similar to the female solution.ConclusionThe importance of developing models for males and females separately was evidenced by the male and female classes being differentially associated with mental health variables.  相似文献   

Association between psychosocial stressors with emotional and behavioral problems among children of low-income addicted families living in Brazil     

《Child abuse & neglect》2019

BackgroundChildren exposed to substance use in their families are vulnerable to multiple risk factors in their development and at increased risk for emotional and behavioral problems. The aims of the study were as follows 1) estimate the prevalence of emotional and behavioral problems among children aged 6–11 years old, living with addicted family members in a low-income urban community of São Paulo, Southeastern Brazil; 2) evaluate the children’s exposure to family psychosocial stressors and substance use; and 3) investigate the factors related to the increased risk of emotional and behavioral problems and substance use.MethodsA cross-sectional study was conducted among 101 children aged 6–11 years old (M = 9.16 years, SD = 1.61). The instruments used were a sociodemographic questionnaire, the Child Behavior Checklist (CBCL) and the Psychosocial Stress Factors (PSF).ResultsHigh prevalence of problems was found for this sample: the CBCL showed 26.7% of clinical scores for Internalizing Problems, 40.6% for Externalizing Problems, and 40.6% for Total Problems. Exposure to family psychosocial stressors was also high, including severe disease (33%), physical aggression (28.9%), death (27.8%), psychiatric hospitalization (16.7%), suicide attempts (15.5%), and suicide (9.3%). Exposure to these family stressors was associated with an increase of two to four times in the prevalence of internalizing and externalizing problems.ConclusionsChildren exposed to substance abusers have more mental health problems than general population, even when compared to peers living in similar low-income areas. This is a group that should be target of a selective preventive intervention.  相似文献   

对韩国文献太极拳理论研究的计量学分析*     

焦〓春  李爱增 《广州体育学院学报》2019,(1):60-64

太极拳是我国首批非物质文化遗产，作为中国传统民族特色的文化形态，近年来也越来越受到世界各国人民的喜爱，在世界范围内影响广泛、传播迅速。通过对韩国学术界的太极拳文献进行计量学统计分析，着重分析了文献的发表时间、作者、发行单位、研究主题和研究方法，旨在研究太极拳在韩国的发展史和传播过程，从社会学、文化学、体育学、传播学等角度，探索太极拳在异国推广和传播的规律及有效的推广方法，以期太极拳在世界大舞台上发扬光大，将太极拳的正能量传播到世界的各个角落。  相似文献   

协同搜索过程中用户交流内容与模式研究     

张璐  张鹏翼  刘畅 《图书情报知识》2020,(3):51-62

[目的/意义]旨在分析协同搜索用户在信息搜索任务过程中的交流内容与模式,从而理解协同搜索用户的关注重点与搜索过程。[研究设计/方法]基于书籍交互检索平台(CLEF-Social Book Search)设计实验,共招募18名被试完成两种搜索任务,通过录音记录对话并对其进行编码和分析,总结交流内容特征和模式。结合任务类型、认知类型组合、服务器记录的搜索交互行为日志以及问卷收集的搜索体验进行了探索分析。[结论/发现]从交流内容上看,协同搜索用户主要理解与评判书目信息、商讨搜索任务计划;比起认知类型不同的用户,相同认知类型的用户在操作交互方面交流更多,在评判决策方面交流较少。交流模式依据讨论内容比重可分为理解评判型、评判主导型、均衡交流型三种,评判主导型用户的任务完成满意度最高。[创新/价值]协同搜索用户的交流反映出搜索过程中需要与同伴商讨协同的焦点,也是需要系统提供协助的重点,给协同搜索系统设计提供一定参考。本研究针对协同搜索的交流内容设计的编码系统对相关的协同交流研究也有借鉴意义。  相似文献   

2018年U18女篮亚青赛日本队进攻特点研究     

高猛  徐校飞  龚闯 《体育科技文献通报》2020,(1):58-61,73

凭借着顽强的团队作风和快速灵活的打法,日本女篮近些年多次站在亚洲最高领奖台上,成为中国队的劲敌,无论是青年队还是成年队都给中国队前进路上带来了不少阻碍。俗话说“知己知彼,百战不殆”。本研究运用录像视频分析法、文献资料法及数理统计法,对获得2018年U18女篮亚青赛亚军的日本队进攻特点进行研究与分析。通过对日本队的进攻特点进行研究与分析从而为我国青少年篮球后备人才的培养提供更加广阔的参考依据与培养方案。  相似文献   

Twenty-four-hour movement behaviours and fundamental movement skills in preschool children: A compositional and isotemporal substitution analysis     

Jéssica Gomes Mota  Cain Craig Truman Clark  Luís Lemos  Cézane Priscilla Reuter  Jorge Augusto Pinto Silva Mota 《Journal of sports sciences》2020,38(18):2071-2079

ABSTRACT

Studies that have analysed the association between the different movement behaviours and fundamental movement skills (FMS) have considered it in an independent manner, disregarding the compositional nature of 24-h movement behaviours (24-h MB). The aim of this study was to investigate the relationship between the 24-h MB and FMS in preschoolers using a compositional data analysis . Two hundred and four preschoolers (4.5 ± 0.8 years old; 101 boys) provided objectively assessed physical activity (PA) and sedentary behaviour (SB) data (Actigraph wGT3X), and FMS (TGMD-2). Sleep duration (SD) was reported by parents. Association of daily composition of movement behaviours with FMS was explored using compositional analysis and isotemporal substitution (R Core Team, 3.6.1). When considered as a 24-h MB composition (PA, SB and SD), adjusted for age, BMI and sex, the composition predicted locomotor (r² = 0.31), object control (r² = 0.19), and total motor score (r² = 0.35), respectively (all P < 0.001). Reallocation of time from light to moderate-to-vigorous PA was associated with greatest positive changes in total motor score. Achieving adequate balance between movement behaviours over the 24-h period, and its relationship with locomotor and object control skills should be considered and further investigated in early childhood.  相似文献   

Impact of digital surge during Covid-19 pandemic: A viewpoint on research and practice     

《International Journal of Information Management》2020

The Covid-19 pandemic has led to an inevitable surge in the use of digital technologies due to the social distancing norms and nationwide lockdowns. People and organizations all over the world have had to adjust to new ways of work and life. We explore possible scenarios of the digital surge and the research issues that arise.An increase in digitalization is leading firms and educational institutions to shift to work-from-home (WFH). Blockchain technology will become important and will entail research on design and regulations. Gig workers and the gig economy is likely to increase in scale, raising questions of work allocation, collaboration, motivation, and aspects of work overload and presenteeism. Workplace monitoring and technostress issues will become prominent with an increase in digital presence. Online fraud is likely to grow, along with research on managing security. The regulation of the internet, a key resource, will be crucial post-pandemic.Research may address the consequences and causes of the digital divide. Further, the issues of net neutrality and zero-rating plans will merit scrutiny. A key research issue will also be the impact and consequences of internet shutdowns, frequently resorted to by countries. Digital money, too, assumes importance in crisis situations and research will address their adoption, consequences, and mode. Aspects of surveillance and privacy gain importance with increased digital usage.  相似文献   

互联网背景下微课与大学武术课堂教学的融合研究     

闫晓鹏  陈维富  王光军  周龙峰  刘朝霞  张宗程  李林 《中华武术(研究)》2020,(1):92-96

采用文献资料法、逻辑分析法等研究方法,以信息技术为手段,以微课与高校大学武术课堂教学为研究对象,在界定微课的定义、典型特征的基础上,探讨开发武术微课必要性,明确开发制作高质量微课的五大要点(确定武术微课的选题,高精尖的设备和制作技术,教师的专业水平,素材的收集整合,微课设计微而全),并对实现微课与大学武术课堂相融合进行了理论分析并得出结论。本研究旨在为武术课程资源的新开发以及武术教学质量的提高提供可操作性的新思路。  相似文献