Fused empirical mode decomposition and wavelets for locating combined damage in a truss-type structure through vibration analysis     

Arturo Garcia-Perez  Juan P. Amezquita-Sanchez  Aurelio Dominguez-Gonzalez  Ramin Sedaghati  Roque Osornio-Rios  Rene J. Romero-Troncoso 《浙江大学学报(A卷英文版)》2013,14(9):615-630

Structural health monitoring （SHM） is a relevant topic for civil systems and involves the monitoring, data processing and interpretation to evaluate the condition of a structure, in order to detect damage. In real structures, two or more sites or types of damage can be present at the same time. It has been shown that one kind of damaged condition can interfere with the detection of another kind of damage, leading to an incorrect assessment about the structure condition. Identifying combined damage on struc- tures still represents a challenge for condition monitoring, because the reliable identification of a combined damaged condition is a difficult task. Thus, this work presents a fusion of methodologies, where a single wavelet-packet and the empirical mode decom- position （EMD） method are combined with artificial neural networks （ANNs） for the automated and online identification-location of single or multiple-combined damage in a scaled model of a five-bay truss-type structure. Results showed that the proposed methodology is very efficient and reliable for identifying and locating the three kinds of damage, as well as their combinations. Therefore, this methodology could be applied to detection-location of damage in real truss-type structures, which would help to improve the characteristics and life span of real structures.  相似文献   

基于模因论的“背诵-仿写-创新”大学英语写作教学模式实证研究     

沈玉如  邓宇 《乐山师范学院学报》2013,(10):135-140

为了验证将模因论运用于大学英语写作教学的效果,文章采用实证研究的方式,在大学英语写作教学中实施了“背诵—仿写—创新”的教学模式。实验结果表明,基于模因论的“背诵—仿写—创新”大学英语写作教学模式有助于改进学生的英语学习习惯、写作习惯以及对英语学习和写作的态度,能有效提高其英语写作能力及整体英语水平,因此,是一种有效的大学英语写作教学模式。  相似文献   

文科专款图书保障与助力科研的实证研究:以历史学科为例     

张洪元  涂文波 《大学图书馆学报》2013,31(2):20-25

统计武汉大学历史学院师生2000-2010年在核心期刊上发表论文的外文参考文献,并发放了读者调查问卷.在此基础上,进行了引文分析和读者调查分析,并比对了CASHL和本馆收藏情况,从而了解读者利用文科专款藏书情况和读者需求的发展趋势,为CASHL完善文献保障能力和服务水平提供了建议.  相似文献   

两总体方差差异的经验似然置信区间     

钱永江 《毕节学院学报》2009,27(4)

通过讨论两总体方差差异的经验似然的大样本性质,证明了经验似然比统计量依分布收敛于X2随机变量,由此给出方差差异的经验似然置信区间.  相似文献   

中国十大城市群“能源-环境-经济”综合核算体系评估实证研究     

曾鹏  陈芬 《中国科技论坛》2012,(8):107-113

中国十大城市群在不断适应区域经济一体化,完善其政治、经济、文化职能的同时,在"能源-环境-经济"这一核算体系中还存在着较大的差异,通过构建城市群"能源-环境-经济"综合核算评估指标体系,采用因子分析与聚类分析相结合的综合集成评估方法,对中国十大城市群"能源-环境-经济"综合核算体系进行实证研究,归纳总结出中国十大城市群不同发展程度的差距和类型,结合"能源-环境-经济"的综合协调发展方面,提出尽快缩小城市群之间的发展差距的相关措施。  相似文献   

大健康背景下医学类高校科技成果转化影响因素研究     

张丹  刘虹妍  沈阳  袁军 《科技管理研究》2018,(11)

围绕医学类高校科技成果转化的影响因素,本研究基于技术供给方的视角提出了研究问题并编制了《医学类高校科技成果转化状况调查表》,采用问卷调查法对34所医学类高校进行施测,共回收670份有效问卷。因素分析表明：影响医学类高校科技成果转化的因素有管理基础、人员基础、转化努力、全链条助力和人员激励5个维度;同时,路径分析表明,管理基础和全链条助力对于所选取的34所医学高校的科技成果转化绩效影响显著。  相似文献   

舆论研究:从思辨到实证     

许静 《国际新闻界》2009,(10)

本文首先强调,包含等级制和驭民术思想的中文传统语境下的舆人之论,与戊戌变法时期梁启超等人倡导的立宪民主思想下的舆论概念,有着根本差异。文章简要回顾了西方自古希腊以来诸多思想家对舆论概念的颠覆与再颠覆过程,以阐明舆论研究有着很长的政治思辨传统。文章其次分析了当前国内外学术界对舆论本质的五种基本看法及其研究取向,并最后以实例证明,实证研究应成为现代舆论研究的发展方向。  相似文献   

Research on action–emotion style and study habits: Effects of individual differences on learning and academic performance of undergraduate students     

Jesús De la Fuente  Maria Cardelle-Elawar   《Learning and individual differences》2009,19(4):567-576

The present study addresses two objectives regarding motivational and affective variables which affect undergraduate students' learning outcomes. In this investigation, we (1) built an empirical model based on the presage–process–product paradigm to clarify potential effects of study habits and of action–emotion style (a classification resulting from analyses of the components of the Type-A Behavior Pattern) on students' academic performance; and (2) evaluated relations of inter-dependence between levels of TABP components, study habits and undergraduate students' academic performance. We used two different samples of 360 and 409 university students from different programs at a university in southeastern Spain. Findings suggest that action–emotion style is a predictor for explaining students' individual differences in motivation and learning outcomes. The research results of this study, although exploratory in nature, are discussed with respect to implications at the research and practical level.  相似文献   

相对资源承载力模型的改进及其实证分析   总被引：11，自引：2，他引：9  

李泽红  董锁成  汤尚颖 《资源科学》2008,30(9):1336-1342

对比区域相对资源人口与经济承载力理论值与实际人口和经济量,有助于了解案例区相对于参照区的发展状态,并能为合理调控案例区人口和经济规模以及确定其未来开发策略提供指导性认识.相对资源承载力测算普遍采用加权线性和模型,其弊端主要在于过多的权重选择和对不同类型资源之间匹配关系的忽视影响了测算的准确性和科学性.基于此对传统相对资源承载力模型进行了改进,提出了几何相对资源承栽力模型,并利用新模型,以全国为参照区,对湖北省1978年～2006年相对资源承栽力进行了实证分析.研究表明,目前湖北省正处于人口超载,经济发展不足的阶段,经济发展不足制约了对人口的容纳能力,未来应成为国家重点开发的省份和经济活动集聚的地区之一.  相似文献   

First-mover advantage and the private value of public science     

《Research Policy》2023,52(9):104867

Technical progress increasingly relies on the use of scientific knowledge. But if much of this knowledge is in the public domain, can it be a source of private value? We find that average private returns to using public science are small, especially in crowded technical fields. This is consistent with the view that the expected profit from an input that competitors can easily access is low. However, private value is higher when a firm is the first to use science, partly because it can secure broader patents relative to later users. Corporate participation in scientific research is a strong predictor of first use, consistent with the view that participation in science raises familiarity with relevant scientific advances.  相似文献