冷藏集装箱制冷装置可靠性统计分析     

江彦桥  王世良 《上海海事大学学报》1994,(3)

根据收集到的某航运公司４３１８只自备和长期租用的冷藏集装箱在４年多时间内的现场故障数据，采用截尾寿命数据分析的技术，求解了当部分样本失效时，母体的参数估计值和冷藏集装箱制冷装置的主要部件如压缩机、膨胀阀以及蒸发器的可靠性概率密度函数等可靠性特征值。文章还讨论和考察了Ｄａｉｋｉｎ，ＰａｕｌＫｌｉｎｇｅ，Ｍｉｔｓｕｂｉｓｈｉ和Ｃａｒｒｉｅｒ４种主要集装箱制冷装置的可靠性特性。  相似文献   

矿井自动排水系统综述     

植海深  卢德明  张应红  徐晋勇  侯原亮 《大众科技》2012,(6):120-122

叙述矿井自动排水系统的组成和工作方式,介绍了矿井自动排水系统的分类和某些系统硬件的安装及作用,讲述大多数矿井自动排水系统具备的特点,最后分析系统中PCL的可靠性及其解决办法。  相似文献   

提高重点装置液位测量可靠性的方法     

陈干 《科教文汇》2012,(33):92-93

石油、化工生产系统中,有的装置中液位控制极为重要,有时牵涉系统的重大安全风险问题,它要求自动控制系统中采集的液位信息具有高可靠性.本文针对液位变送器在生产过程中出现的失真,造成DCS系统控制失灵的问题,提出可靠的报警解决办法.  相似文献   

怎样提高产学研合作案例研究的效度与信度?     

原长弘  田元强  佘健华 《科学学与科学技术管理》2012,33(7):29-36

利用评价指标体系和文献分析,探讨了产学研案例研究的效度与信度。结果表明:国内外期刊上业已发表的产学研案例研究并没有充分报告案例研究的效度与信度,这些研究在构念效度、内部效度、外部效度和信度上是不严谨的。并提出了提高产学研案例研究效度与信度的改进建议。  相似文献   

主题统觉测验的研究与应用现状     

林荣茂  胡海沅 《牡丹江教育学院学报》2010,(5):87-88

主题统觉测验是最主要的投射测验之一,它的理论基础是需要——压力理论。研究者对主题统觉测验材料,标准化及信效等方面进行了深入的研究。虽然对主题统觉测验还存在不少争议,但作为一种重要的间接测量技术,它在一定程度上避免了直接测量的缺陷,通过与直接测量技术结合,其应用也正走向多样化。  相似文献   

高职院校思想政治理论课教学信度的探析     

孙鉴 《宁波教育学院学报》2010,12(6)

提高高职院校思想政治理论课教学信度,是充分发挥思想政治课德育功能的要求,是提高思想政治理论课教学质量的需要。通过对影响思想政治理论课教学信度的分析,提出增强高职院校思想政治理论课信度的策略。  相似文献   

单自由度强迫振动的可靠性     

莫文辉 《十堰职业技术学院学报》2013,26(1):97-99

随机因素对振动的影响不可忽略。本文将质量刚度、阻尼系数看作随机变量,研究了单自由度强迫振动的共振频率的可靠性。对随机变量进行计算机模拟,产生大量样本。应用Monte Carlo模拟研究了振动位移的可靠性。模拟次数越多,求得的可靠度精度越高。算例表明本文方法是正确的。  相似文献   

Peer assessment in group projects accounting for assessor reliability by an iterative method     

Sung-Seok Ko 《Teaching in Higher Education》2013,18(3):301-314

This study proposes an advanced method to factor in the contributions of individual group members engaged in an integrated group project using peer assessment procedures. Conway et al. proposed the Individual Weight Factor (IWF) method for peer assessment which has been extensively developed over the years. However, most methods associated with IWF use a simple average algorithm which still has limitations in effectively reflecting abnormal situations. Therefore, this study proposes an iterative method for measuring a fair IWF by considering each assessor's reliability. The proposed algorithm considers each assessor's reliability which is evaluated by an analysis of variance of the scores given by the assessor. This relative reliability factor is used to improve the fairness of the IWF and reduce the effect of unfair or unreliable assessors' scores. A comparison with previous methods demonstrates that the proposed method resulted in substantially more fair grades being given to individual students for group projects.  相似文献   

Gains in marking reliability from item-level marking: is the sum of the parts better than the whole?     

Christopher Wheadon  Anne Pinot de Moira 《Educational Research and Evaluation》2013,19(8):665-679

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The reliability and validity of the pupil behaviour questionnaire: a child classroom behaviour assessment tool     

Matt Allwood  Kate Allen  Anna Price  Rachel Hayes  Vanessa Edwards  Susan Ball 《Emotional and Behavioural Difficulties》2013,18(4):361-371

ABSTRACT

This paper assesses the reliability and validity of the teacher-completed Pupil Behaviour Questionnaire (PBQ), by comparing it to the already extensively validated teacher-completed Strengths and Difficulties Questionnaire (SDQ). Participants included 2074 primary school children participating in a universal school-based trial and 41 vulnerable children who were taking part in a study exploring the impact of exclusion from school. Exploratory factor analysis results (first factor accounts for 80.8% of the variation in the items) and the high Cronbach’s alpha value of 0.85 indicate that the PBQ consists of one substantive factor/dimension. Strong correlations between the total PBQ score and the conduct sub-scale (Spearman’s correlation coefficient (r_s) = 0.67) and total difficulties score (r_s = 0.59) of the SDQ indicate convergent validity. This study suggests that the PBQ is a reliable measure, and provides some evidence of validity. Further work is needed to test the PBQ in an older, more diverse populations and to measure sensitivity to change.  相似文献