基于物联网、J2EE技术的农业大棚预警监测系统设计     

彭逆  赵奎  张鹏 《环球赛鸽科技》2013,(25)

本文基于物联网和J2EE技术,设计了一套农业温室大棚预警监测系统,旨在通过对温室大棚内环境因子数据的采集、智能分析、处理实现对大棚的智能监测、自动预警功能,使温室大棚高效高质产出。  相似文献   

Effect of tapering period on plasma hormone concentrations,mood state,and performance of elite male cyclists     

《European Journal of Sport Science》2013,13(3):183-190

Abstract

In this study, we investigated the effect of 1- and 3-week tapering periods on concentrations of plasma testosterone (T), cortisol (C), T/C ratio, mood state, and performance in elite male cyclists. After 8 weeks of progressive training, cyclists were randomly assigned to a control group (n=12) who continued performing intense training for a further 3 weeks, or a taper group (n=12) who continued with a 50% reduction in training volume. Blood testosterone and cortisol concentrations were assayed and the T/C ratio calculated from analysis obtained via standard ELISA. Mood state was determined using the Profile of Mood States (POMS) questionnaire. All data were collected immediately after a 40-km time-trial performed before, during, and after the 8-week training protocol and after the 1- and 3-week tapering/training periods. In the taper group, 40-km time-trial time decreased significantly (P<0.01) and equally for both the 1- and 3-week taper periods relative to the control group. There were significant elevations in T/C ratio (P<0.001) and reductions in cortisol concentrations and POMS scores in the taper group relative to the control groups at the end of both the 1- and 3-week tapering periods. Hence, taper periods are effective in improving performance and mood state and elevating the blood T/C ratio.  相似文献   

The effect of training on aerobic power characteristics of young cross‐country skiers     

Heikki Rusko 《Journal of sports sciences》2013,31(3):273-286

The influences of growth, training and various training methods were investigated by analysing long‐term training effects in young cross‐country and biathlon skiers (n = 129). Some athletes (n = 49) were studied six times in three years and some at least once a year during a four year period (n = 48). During three summer training periods skiers emphasized either intensive training or distance training or continued to train normally. The results indicated that maximal oxygen uptake (VO₂ max) and heart volume increased between 15 and 20 years of age and the most significant changes in heart volume were observed between 16 and 18 years of age. International level skiers were able to increase their VO₂ max and heart volume even after 20 years of age. Anaerobic threshold (AT, ml kg^‐1 min^‐1) increased like VO₂ max but when expressed as a percentage of VO₂ max, the AT was similar in every age group over 16 years of age. Intensive training at the intensity of anaerobic threshold or higher was observed to be most effective in producing improvements in VO₂ max. Low‐intensity distance training was more effective in producing improvements in anaerobic threshold.  相似文献   

Activity profile of top-class association football referees in relation to performance in selected physical tests     

Javier Mallo  José-María García-Aranda  Bart Gilis  Werner Helsen 《Journal of sports sciences》2013,31(7):805-813

Abstract

The aims of the present study were (1) to analyse the physical demands of top-class referees and (2) to compare their official FIFA fitness test results with physical performance during a match. The work rate profiles of 11 international referees were assessed during 12 competitive matches at the 2003 FIFA Under-17 World Cup and then analysed using a bi-dimensional photogrammetric video analysis system based on direct lineal transformation (DLT) algorithms. In the first 15 min of matches, the referees were more active, performing more high-intensity exercise (P < 0.01) than in the first 15 min of the second half. During the second half of matches, the referees covered a shorter distance (P < 0.01), spent more time standing still (P < 0.05), and covered less ground cruising (P < 0.05), sprinting (P < 0.05), and moving backwards (P < 0.001) than in the first half. Also in the second 45 min, the distance of referees from infringements increased (P < 0.05) in the left attacking zone of the filed. There was also a decrease (P < 0.05) in performance in the period following the most high-intensity activity, compared with the mean for the 90 min. Time spent performing high-intensity activities during a match was not related to performance in the 12-min run (r ² = 0.30; P < 0.05), the 200-m sprint (r ² = 0.05; P < 0.05), or the 50-m sprint (r ² = 0.001; P < 0.05). The results of this study show that: (1) top-class referees experienced fatigue at different stages of the match, and (2) the typical field tests used by FIFA (two 50-m and 200-m sprints, followed by a 12-min run) are not correlated with match activities.  相似文献   

Zigbee无线传感器网络混合路由协议研究     

蔡迎玲  艾文 《人天科学研究》2013,(1):38-40

针对ZigBee无线传感器网络存在能量受限、低速率的问题,深入分析了ZigBee路由协议对网络能耗的影响,并利用网络仿真器NS-2对其性能进行仿真验证。仿真结果验证,采用ClusterTree＋Aodvjr的混合路由协议具有较好的性能。  相似文献   

基于Struts2结构的在线考试系统设计与实现     

唐晔 《人天科学研究》2013,(6):71-72

基于Struts2和J2EE技术框架,结合MySQL数据库,设计并实现了一个基于B/S架构的在线考试系统,重点阐述了用户答题模块的设计,并提出了一种系统随机出题的方法。  相似文献   

不同背景场近地层风速的预报效果检验   总被引：1，自引：0，他引：1  

孙逸涵  何晓凤  周荣卫 《资源科学》2013,35(12):2481-2490

模式初始场的优劣对风预报结果影响较大,中国常用的全球环流背景场为美国NCEP发布的GFS资料、欧洲中心的ECMWF资料以及中国气象局的T639资料。本文收集、整理了2010年6月~2011年5月的上述3套资料,将其分别与中国境内677个基本站、基准站和400座专业测风塔同期测风数据进行对比检验,综合分析GFS、EC、T639在中国区域内的近地层风速预报效果,并给出3套数据预报性能的平面分布图,结合气象站和测风塔处的地形特征和测风数据的代表性,初步判断3套背景场的近地层风速在不同区域、不同季节的可预报性,为中尺度模式选择初始场开展风速预报服务时提供一定依据。结果表明：①风速介于（0~3）m/s时,气象站和测风塔观测资料检验结果一致,T639资料预报效果最好,GFS资料第二,EC资料第三。风速介于（3~15）m/s时,气象站和测风塔观测资料检验结果有差异,测风塔数据检验,EC资料预报效果最好,GFS资料第二,T639资料第三;气象站资料检验,GFS资料预报效果最好,EC资料第二,T639资料第三。风速介于（15~25）m/s时,气象站和测风塔观测资料检验结果一致,EC资料预报效果最好,GFS资料第二,T639资料第三;②基于（3~15）m/s风速段,中国东北、华北、西北、西南地区,全年EC资料预报效果最好,GFS第二,T639第三,但秋冬季在西南地区三套资料的预报效果均较差。华东地区,春秋季时,EC和GFS资料预报效果一致,优于T639;夏季时,EC资料预报效果最好,GFS第二,T639第三;冬季时,3套资料预报效果一致。中南地区,春、秋、冬季时,EC资料预报效果最好,GFS和T639资料预报效果一致;夏季时,3套资料预报效果一致。  相似文献   

FTGS音频轨道电路测试仪设计与实现     

唐匀生  黄斌 《大众科技》2013,(1):29-31

为了增强学习兴趣和操作动手能力,增加城轨专业的实训、实验内容。利用STC1T单片机设计出一套FTGS音频轨道电路测试系统,可以测量FTGS音频轨道电路的电压、载频及位模式等参数,并对两种载频及3种位模式的组合进行了测量实验。结果表明,该系统能很好的测量FTGS音频轨道电路的信息参数,完全满足学生学习、测量使用。  相似文献   

基于Davinci的嵌入式网络视频监控系统的设计与实现     

郝付壮  张彤 《大众科技》2013,(4):23-25

介绍了一种基于TMS320DM368处理器的网络视频监控系统的实现方案,该系统支持扩展多种视频采集前端接口,支持包括以太网、3G网络和WIFI的多种通信方式。基于RTP/RTSP框架设计了多线程流媒体服务器,并在Web服务器端设计了动态页面,使用CGI技术实现了用户与服务器的交互。测试结果显示系统在低带宽和复杂网络条件下仍能获得很好的监控画面效果,实时性和稳定性好。  相似文献   

基于小区域断点检测的P2P网络快速通行算法     

张鑫 《科技通报》2013,(10)

提出一种自主感应分析算法,针对通信小区域内的断点,设计最优路径选取方法。计算路径中的相关断点权值,为每个路径的选择设计相关的阀值标准,选取最优路径,避免断点区域路径的选择,同时也避免了传统方法逐个遍历网络节点带来的通信效率过低的问题。实验证明,利用该方法能够快速选取通信最优路径,有效提高了P2P网络通信效率,取得了满意的结果。  相似文献