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基于状态维修(CBM, Condition Based Maintenance)方法是预防性维修方法的一种,它以比例风险模型(PHM,Proportional Hazard Model)为基础,强调运行时间和实时状态对设备运行寿命的影响,通过设备运行的历史数据和实时运行状态来评估其可靠性。本文在PHM模型的基础上,利用灰色模型估计模型中风险度函数的相关参数,使之适应于消防水泵失效数据较少的情况,提出了适应小样本数据的设备状态评估方法。并以实际使用的消防水泵泄漏量作为计算状态量,采用CBM方法计算了水泵的可靠度、风险度,计算结果显示该方法能够评估设备的运行状态,并能优化设备维修策略,节约维修成本。 相似文献
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为了深入分析与评估大学生体育舞蹈综合素质变化情况,确立了一种用于系统化评估大学生体育舞蹈综合素质变化的整体思路,选择了评估参照信息并给出其测度方法;结合当代体育舞蹈特色确定了评估指标并给出评估指标的计算方法;随后,基于泛函分析方法建立了大学生体育舞蹈综合素质动态变化的评估模型,说明了模型的功能及使用方法,以湖南商学院为例进行评估实验验证了本文方法可行性、实用性、有效性。 相似文献
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神经网络算法的收敛性和稳定性已经得到了广泛的证明,被应用在许多工业监控场合,在传统的BP神经网络预测基坑变形方法的基础上,融入了灰色算法,生成了一种新的智能化模型,以对原有方法进行优化。通过实际案例证明,新的组合模型无论在计算时间还是在计算精度方面,都显示了较为明显的优势,具有一定的经济意义和实用价值。 相似文献
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孙艳 《西安体育学院学报》2002,(Z1)
将现在执行的大学生国家体育锻炼标准采用的分档计分法改进为对应计分法,给出了对应计分法对于不同项目计算得分的计算公式和等级评定标准,结合应用给出了对应计分法的计算模型和计算例。 相似文献
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采用数理统计方法及例证等,介绍了在运动训练控制领域中灰色系统模型分析方法的运用。在运动训练领域中,灰色关联模型分析可以用于运动员的选材和各训练指标的权重值计算;灰色协调模型可以用于竞技实力的强、弱项分析以及各训练指标值的调控;灰色预测模型可以预测未来的比赛成绩。运用于运动训练领域中的多种灰色系统模型分析方法,能够较为科学地为运动训练控制过程的实施提供参考。 相似文献
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根据体育教师综合素质变化情况,确立了一种用于系统化评估的整体思路,选择了评估参照信息并给出其测度方法;结合当代体育教育对教师综合素质需求确定了评估指标并给出评估指标的计算方法;基于测度论建立了教师综合素质动态量化评估模型,以湖南商学院、国防科技大学为个案进行评估实验,说明方法的有效性. 相似文献
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在集体项目比赛中,为了能够较为合理地选派上场队员,本文列举一种优选方法,该方法能在较复杂的情况下帮助决策者正确地作出决策。文中给出了该方法的原理、模型及计算步骤。 相似文献
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人体机械功计算方法的实验研究 总被引：1，自引：1，他引：0
人体运动中的机械功是评定运动效果的一个重要指标,由于人体生物结构的复杂性和器官功能的多重性特点,目前还没有形成公认的分析计算方法。本研究首先在作者提出的假设之下给出四类人体机械功计算的可能方法。采用Monark864型自行车功率定负荷,JagerEOS型心肺功能测试仪测室生理能耗,用环节分析法计算机械功。14名受试都是职业自行车队队员。本研究结果提示:采用刚体力学模型计算的人体机械功可看作是运动中生理能耗的一次近似,要提高计算准确度,还需考虑其它耗能因素,建立更为精细的人体能量代谢模型。 相似文献
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This study examined the effect of carbohydrate ingestion on metabolic and performance-related responses during and after a simulated 1h cycling time trial. Eight trained male cyclists (VO 2 peak = 66.5ml kg -1 min -1 ) rode their own bicycles mounted on a windload simulator to imitate real riding conditions. At a self-selected maximal pace, the cyclists performed two 1h rides (separated by 7 days) and were fed either an 8% carbohydrate or placebo solution. The beverages were administered 25 min before (4.5ml kg -1 ) and at the end (4.5ml kg -1 ) of the ride. With carbohydrate feeding, plasma glucose tended (P = 0.21) to rise before the time trial. Compared with rest, the plasma glucose concentration decreased significantly (P < 0.05) at the end of both rides, with no statistically significant difference being observed between treatments. Thereafter, plasma glucose increased significantly (P < 0.05) at 15 and 30 min into recovery, and was significantly higher at 30 min during the carbohydrate trial compared with the placebo trial. No significant changes in plasma free fatty acids were observed during the ride. However, a significant increase (P < 0.05) in free fatty acids was found at 15 and 30 min into recovery, with no difference between trials. Mean power output was significantly (P < 0.05) greater during the carbohydrate compared with the placebo trial (mean - S.E.: 277-3 and 269-3W, respectively). The greater distance covered in the carbohydrate compared with the placebo trial (41.5-1.06 and 41.0–1.06km, respectively; P < 0.05) was equivalent to a 44s improvement. We conclude that pre-exercise carbohydrate ingestion significantly increases endurance performance in trained cyclists during a 1h simulated time trial. Although the mechanism for this enhancement in performance with carbohydrate ingestion cannot be surmised from the present results, it could be related to a higher rate of carbohydrate oxidation, or to favourable effects of carbohydrate ingestion on the central component of fatigue. 相似文献
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Roy J. Shephard 《Journal of sports sciences》2013,31(7):603-620
The biology and medicine of rowing are briefly reviewed. Effort in a 2000 -m race is about 70% aerobic. Because the boat (and in some instances a cox) must be propelled, successful competitors are very tall, with a large lean mass and aerobic power. Large hearts may lead to erroneous diagnoses of a cardiomyopathy. Large respiratory minute volumes must be developed by chest muscles that are also involved in rowing. The vital capacity is typically large, and breathing becomes entrained. Expiration cannot be slowed relative to inspiration (as normally occurs at high rates of ventilation) and the limiting flow velocity may be reached, with the potential for airway collapse. Performance is strongly related to the power output at the ‘anaerobic threshold’, and lactate measures provide a guide to an appropriate intensity of endurance training. Peak blood lactate levels are higher in males (commonly 11–19 mmol·l -1 and occasionally as high as 25 mmol·l -1) than in females (9–11 mmol·l -1), probably because males have a greater muscle mass in relation to blood volume. The skeletal muscles are predominantly slow twitch in type, developing an unusual force and power at low contraction velocities. Many rowers have a suboptimal diet, eating excessive amounts of fat. Lightweight rowers also have problems of weight cycling. Aerobic power and muscle endurance often change by 10% over the season, but such fluctuations can be largely avoided by a well-designed winter training programme. Injuries include back and knee problems, tenosynovitis of the wrist and, since the introduction of large blades, fractures of the costae. 相似文献
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许良 《体育科技文献通报》2011,19(2):1-4
基于1985、1995和2005年全国学生体质调研数据,对各时期我国城乡学生形态、机能、体能发展水平进行系统地定量研究,动态分析20年全国城乡学生体质发展的特点与规律。主要研究结果：（1）近20年城乡学生生长发育持续提前,城市学生各项形态指标生长水平高于乡村,身高城乡差距缩小,体重、胸围城乡差距加大;（2）城市学生肺活量水平高于乡村,城乡学生肺活量20年持续下降,前10年乡村学生下降快、后10年城市学生下降快;（3）乡村学生800m、1000m跑水平高于城市,城市女生50m跑、仰卧起坐水平高于乡村,其他素质城乡学生水平波动较大;（4）城市女生50m跑20年持续下降,城乡学生800m和1000m跑、城市学生50m×8往返跑20年加速下降,其他素质20年间有增有降发展极不平稳。 相似文献
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采用测量、问卷调查、数理统计等方法,分析定向运动学习前后对大学生身心健康的影响.结果经T检验和x2检验且表明：定向运动不仅能增强学生体质健康水平,而且有助于学生的情绪调节,增强自信心与创新意识,培养勇敢顽强的意志品质,建立良好的人际关系,能有效地促进学生身心健康发展.为了全面提高大学生整体素质,积极实践,构建定向运动课内外一体化教学模式,进行定向运动课程模块化教学,以满足学生的多元化需求. 相似文献
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Alan M. Nevill Roger L. Holder Andrew Bardsley Helen Calvert Stephen Jones 《Journal of sports sciences》2013,31(4):437-443
A regression analysis of competitors' tournament results in relation to their world rankings was proposed to identify the effect of home advantage in international ‘grand-slam’ tennis and ‘major’ golf tournaments. The results provided little evidence of home advantage in either the grand-slam tennis or the golf tournaments held in 1993. The only possible evidence of home advantage was found in the Wimbledon tennis and the US Open golf championships. Even these findings can be explained, at least partially, by (1) the availability of information concerning the low world rankings of the British tennis players competing at Wimbledon, and (2) selective entry, allowing only the world's top-ranked foreign golfers into the US open golf tournament. In both cases, the lower ranking home competitors have a greater opportunity to perform above their anticipated world rankings. Therefore, provided entry into tennis and golf tournaments is truly ‘open’ to both the host nation's representatives and foreign competitors alike, home advantage does not appear to be a major factor influencing the competitors' performance in such competitions. These findings may be explained by the relatively objective nature of the scoring systems used in tennis and golf, unlike the subjective influence of refereeing decisions on the results of team-games such as soccer. 相似文献
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曲爱宁 《体育科技文献通报》2007,15(8):97-98
柔韧素质是健美操专业学生的专项素质之一,通过对普通高校健美操专业学生分组对照进行柔韧性训练的实验研究,认为对训练肌群辅以按摩器振颤刺激,可大大提高柔韧性训练效果。 相似文献
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我国城市体育自然环境建设与发展的研究 总被引：5，自引：0，他引：5
采用实地调查研究、理性思维研究和文献资料调研等方法对主要问题进行了专门研究，提出了进行城市体育场所区域生态功能区划、设计体育生态功能区布局的方案、做好体育场所绿色环境系统规划、制定体育场所生态与绿地管理措施等基本观点，提出了若干城市体育自然环境建设与发展的对策。 相似文献
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重新认识体育的社会关联 总被引：3，自引：1，他引：2
体育与政治之间存在一个悖论，体育的发展与经济实力之间没有直线相关，体育与教育部分重叠，体育与宗教最为近缘，体育可借用科学手段，体育的艺术禀性日益明显，体育与养生反映着两种人生观。 相似文献