混凝土湿喷台车臂架振动模态分析

以国内某公司喷浆台车SPTC25为研究对象,首先利用陀螺仪和加速度传感器在施工现场进行动力学测试,采集到关于臂架在实际施工时的角速度和加速度的时间历程曲线。然后通过数据处理和分析计算,得到臂架在仰俯工况下的振动频率和振幅,分别为1.18 Hz和0.092 m,回转工况下的振动频率和振幅分别为0.98 Hz和0.073 m。其次,对湿喷台车臂架建立了准确的有限元模型,并且进行了模态仿真分析,得到前三阶模态的固有频率和振型。结合隧道施工时的实际操作数据统计,最终得出结论,臂架在施工过程中长时间处于共振状态,使得振幅过大,这是臂架疲劳开裂的主要原因,也为后续湿喷台车臂架的研发和优化提供了新的分析思路。     

Can the behavioral sciences self-correct? A social epistemic study

Advocates of the self-corrective thesis argue that scientific method will refute false theories and find closer approximations to the truth in the long run. I discuss a contemporary interpretation of this thesis in terms of frequentist statistics in the context of the behavioral sciences. First, I identify experimental replications and systematic aggregation of evidence (meta-analysis) as the self-corrective mechanism. Then, I present a computer simulation study of scientific communities that implement this mechanism to argue that frequentist statistics may converge upon a correct estimate or not depending on the social structure of the community that uses it. Based on this study, I argue that methodological explanations of the “replicability crisis” in psychology are limited and propose an alternative explanation in terms of biases. Finally, I conclude suggesting that scientific self-correction should be understood as an interaction effect between inference methods and social structures.     

基于统计数据模型的优秀教练评判的影响因素分析

利用模糊综合评价的方法,根据美国大学教练统计数据的特征分析,从教练的执教胜率,执教年数和获得荣誉等因素来综合评价教练的排名,并运用灵敏度分析的方法分析了各项指标对评判结果的影响因素.     

New Robust Global Motion Estimation Approach Used in MPEG-4

The Global Motion Estimation ( GME)technique is importantfor‘sprites’ generation andobject segmentation tasks involved in MPEG- 4.This paper presents a new robust GME approachusing the novel idea to pre- analyze scene contentbefore motion estimation. The pre- analysis isbased on Spatial Temporal Gradient Scale ( STGS)images derived from the original image sequences.As a result,outliers can be removed from thedominant motion estimate at the initial estimationstep. Compared with class…     

α稳定噪声下基于随机共振的微弱诱发电位潜伏期延长检测

提出了一种基于分数低阶统计量及随机共振技术的鲁棒性时问延迟估计新方法--随机共振共变时间延迟估计(SRCTDE)算法,用于在低混合信噪比条件下及a稳定噪声下微弱诱发电位信号潜伏期延长的检测.SRCTDE算法首先利用带嗓诱发电位信号与双稳态非线性动力系统之间的随机共振效应提高参考及待测诱发电位信号的混合信噪比,在最大对称...     

区域洪涝灾害风险估算模型及其应用

为了减轻洪涝灾害造成的损失,针对系统存在的风险指标,研制区域洪涝灾害风险估算模型.应用马尔科夫链进行某种趋势外推型的风险预测,并估算洪涝灾害无实测值的状态;采用贝叶斯统计理论和方法,通过先验分布结合样本信息来推求后验分布,以最大概率原则判别风险估算的趋势,按照估算结果及当地的实际情况,适度调整针对洪涝灾害的策略,尽可能...     

浅谈数理统计在工程中的运用

数理统计是具有广泛应用的一个数学分支,它越来越多地运用于理、工、农、医、文等方面,它在解决现代科学的最重要和最多样化的课题中起着主导作用。在现实生活和工作中,人们也越来越离不开统计。文章主要针对数理统计对工程数据的处理进行论述,用例举法来表述其在工程中的应用。     

概率论与数理统计学习策略的统计分析

采用问卷调查和考试的方法进行调查分析,研究了学习策略对概率论与数理统计学习成绩的影响.结果发现,学习策略和概率论与数理统计学习成绩密切相关,学习策略对概率论与数理统计学习成绩影响显著,学习策略对概率论与数理统计学习成绩有预测作用.     

1999～2009年我国关于“情绪智力”选题的研究状况及分析——基于CNKI硕士、博士学位论文的统计

采用内容分析法,对1999~2009年间CNK I上关于＂智力＂选题的384篇硕士、博士学位论文进行分析的基础上,就其中有关情绪智力这一选题的57篇论文进行了深入分析。     

Retail default prediction by using sequential minimal optimization technique

This paper employed sequential minimal optimization (SMO) to develop default prediction model in the US retail market. Principal components analysis is used for variable reduction purposes. Four standard credit scoring techniques—naïve Bayes, logistic regression, recursive partitioning and artificial neural network—are compared to SMO, using a sample of 195 healthy firms and 51 distressed firms over five time periods between 1994 and 2002. The five techniques perform well in predicting default particularly one year before financial distress. Furthermore, the prediction still remains sound even 5 years before default. No single methodology has the absolute best classification ability, as the model performance varies in terms of different time periods and variable groups. External influences have greater impacts on the naïve Bayes than other techniques. In terms of similarity with Moody's ranking, SMO excelled over other techniques in most of the time periods. Copyright © 2008 John Wiley & Sons, Ltd.