期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
查询优化解决“车站系统”数据库I/O冲突
1
作者 廖国良 马征 《铁路计算机应用》 2006年第12期20-22,共3页
详细阐述优化查询SQL解决“铁路车站系统”数据库I/O冲突的步骤。“车站系统”中某些子系统响应速度非常慢,监视系统性能瓶颈时间段数据库的状态,比较两个以上时间点性能差异,发现引起性能瓶颈的主要问题来自I/O争用。可以通过建立索引... 详细阐述优化查询SQL解决“铁路车站系统”数据库I/O冲突的步骤。“车站系统”中某些子系统响应速度非常慢,监视系统性能瓶颈时间段数据库的状态,比较两个以上时间点性能差异,发现引起性能瓶颈的主要问题来自I/O争用。可以通过建立索引,为查询增加参数,修连接改查询语句书写顺序等手段可以获得更加优秀的数据库查询计划。 展开更多
关键词 对象请求锁命中率 对象库元数据请求命中率 物理 物理写
下载PDF
The association of various social capital indicators and physical activity participation among Turkish adolescents
2
作者 Günay Y1ld1zer Emre Bilgin +2 位作者 Ezel Nur Korur Dario Novak GIyasettin Demirhan 《Journal of Sport and Health Science》 SCIE 2018年第1期27-33,共7页
Background: Physical activity participation(PAP) has been proven to improve health and promote optimal growth among adolescents. However,most adolescents do not meet the current physical activity(PA) recommendations i... Background: Physical activity participation(PAP) has been proven to improve health and promote optimal growth among adolescents. However,most adolescents do not meet the current physical activity(PA) recommendations in Turkey. The role of the social environment and social factors on PAP is being increasingly recognized. Although social capital(SC) indicators have been examined in high-income countries, there are few studies on developing countries. The aim of this study was to examine the relationship between SC indicators and PAP among Turkish adolescents.Methods: A survey was conducted among 19 high schools in 4 different cities in Turkey in 2016. A total of 506 female and 729 male high school students participated in this study. The dependent variable was overall PAP, which was measured using the short form of the International Physical Activity Questionnaire. The independent variables included self-perceived family, neighborhood, and school SC. Self-rated health and obesity status, measured by body mass index, were other study covariates in multiple binary logistic regression models. Chi-square tests were used to assess the differences between genders.Results: PAP levels were significantly different between males and females. A higher percentage of males reported PAP(77.4%) compared to females(51.0%). Among males, teacher–student interpersonal trust and informal social control were inversely associated with PAP, while high students interpersonal trust was positively associated with increased odds of PAP. For females, students interpersonal trust was inversely associated with PAP.Conclusion: Various SC indicators are associated with PAP for males and females. These associations are different from findings of studies conducted in developed countries. Therefore, health-promotion interventions and policies should consider gender and different social agents on the social and cultural background to improve PAP among Turkish adolescents. 展开更多
关键词 Adolescents Family NEIGHBORHOOD Physical activity Public health SCHOOL Social capital
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部