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结合模态区间分析和IARR的不确定性损伤识别 被引量:3
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作者 方圣恩 张宝 《振动.测试与诊断》 EI CSCD 北大核心 2019年第4期810-815,907,共7页
针对结构不确定性损伤识别中经典区间算法容易发生扩张的问题,提出将模态区间分析和改进解析冗余度(improved analytical redundancy reduction,简称IARR)相结合的损伤识别方法。首先,将结构静力平衡方程用约束条件方程组表示,通过改进... 针对结构不确定性损伤识别中经典区间算法容易发生扩张的问题,提出将模态区间分析和改进解析冗余度(improved analytical redundancy reduction,简称IARR)相结合的损伤识别方法。首先,将结构静力平衡方程用约束条件方程组表示,通过改进解析冗余度使得方程组仅包含平动变量;其次,把与假定损伤单元相关的方程集中在同一子集,代入区间变量将方程扩展成区间形式,通过模态区间运算判断各约束条件的满足情况来实现损伤定位;最后,采用静载作用下的试验钢梁验证所提出的方法,结合刚度参数、挠度参数和外荷载3种随机变量,建立各梁段约束条件方程。结果表明:考虑测试误差、参数不确定性时,能通过约束条件的不满足有效定位梁的小损伤。 展开更多
关键词 不确定性损伤识别 模态区间分析 改进解析冗余度 约束满足问题 钢梁试验
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土地利用规划中不确定性的识别和处理研究
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作者 张尤 《科技与企业》 2015年第4期131-131,共1页
土地利用规划是一项系统的工作,提高土地利用规划的质量,可以提高土地资源的利用率。本文对土地利用规划中不确定性的识别以及处理进行了研究,希望对土地规划单位提供一定可借鉴经验。我国市场经济体制在不断的变化与改革,这也使得经济... 土地利用规划是一项系统的工作,提高土地利用规划的质量,可以提高土地资源的利用率。本文对土地利用规划中不确定性的识别以及处理进行了研究,希望对土地规划单位提供一定可借鉴经验。我国市场经济体制在不断的变化与改革,这也使得经济市场的竞争愈加激烈,只有对土地资源进行合理的配置,才能帮助企业在竞争激烈的市场中抢占更多的市场份额。 展开更多
关键词 土地利用规划 不确定性识别 处理
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基于逐步回归分析和Bootstrap重抽样的铁路钢桁桥不确定参数识别 被引量:1
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作者 骆勇鹏 黄方林 +2 位作者 伍彦斌 鲁四平 苏泽平 《公路交通科技》 CAS CSCD 北大核心 2016年第11期104-110,共7页
为获得不确定性参数的概率统计特征,提出一种基于逐步回归分析和Bootstrap重抽样的不确定性参数识别方法。该方法首先根据合理试验设计确定试验点并计算试验点所对应的响应,基于逐步回归分析方法构造表达设计参数和响应关系的最优响应... 为获得不确定性参数的概率统计特征,提出一种基于逐步回归分析和Bootstrap重抽样的不确定性参数识别方法。该方法首先根据合理试验设计确定试验点并计算试验点所对应的响应,基于逐步回归分析方法构造表达设计参数和响应关系的最优响应面模型。进而在小样本的情况下,利用Bootstrap重抽样技术对实测响应进行抽样得到大样本数据,结合响应面模型,通过优化反演来求得各个Bootstrap样本所对应的参数值,经概率统计分析得到参数的均值和标准差。采用一组试验钢板和铁路钢桁桥算例来验证所提方法的可行性和可靠性。结果表明,所提方法可准确地识别出不确定性参数的概率统计特征值;与随机模型修正相比,所提方法在保证精度的前提下,具有更高的计算效率,可用于复杂工程结构的不确定性参数量化分析中。 展开更多
关键词 桥梁工程 不确定性参数识别 Bootstrap重抽样 铁路钢桁桥 模型修正
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Identification of contamination source in water distribution network based on consumer complaints 被引量:3
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作者 陶涛 黄海东 +1 位作者 信昆仑 刘书明 《Journal of Central South University》 SCIE EI CAS 2012年第6期1600-1609,共10页
A new methodology was proposed for contamination source identification using information provided by consumer complaints from a probabilistic view.Due to the high uncertainties of information derived from users,the ob... A new methodology was proposed for contamination source identification using information provided by consumer complaints from a probabilistic view.Due to the high uncertainties of information derived from users,the objective of the proposed methodology doesn't aim to capture a unique solution,but to minimize the number of possible contamination sources.In the proposed methodology,all the possible pollution nodes are identified through the CSA methodology firstly.And then based on the principle of total probability formula,the probability of each possible contamination node is obtained through a series of calculation.According to magnitude of the probability,the number of possible pollution nodes is minimized.The effectiveness and feasibility of the methodology is demonstrated through an application to a real case of ZJ City.Four scenarios were designed to investigate the influence of different uncertainties on the results in this case.The results show that pollutant concentration,injection duration,the number of consumer complaints nodes used for calculation and the prior probability with which consumers would complaint have no particular effect on the identification of contamination source.Three nodes were selected as the most possible pollution sources in water pipe network of ZJ City which includes more than 3 000 nodes.The results show the potential of the proposed method to identify contamination source through consumer complaints. 展开更多
关键词 water distribution network contamination source IDENTIFICATION consumer complaints
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Influence of System Uncertainties on Structural Damage Identification through Ambient Vibrations of Steel Structures
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作者 Leandro Fleck Fadel Miguel: Leticia F. Fadel Miguel +2 位作者 Jorge D. Riera Marta G. Amani Raul O. Curadelli 《Journal of Civil Engineering and Architecture》 2011年第5期454-458,共5页
The practical difficulties presented by forced vibration testing of large steel structures, such as tall buildings, transmission lines or bridges, led to an increased interest in structural monitoring through ambient ... The practical difficulties presented by forced vibration testing of large steel structures, such as tall buildings, transmission lines or bridges, led to an increased interest in structural monitoring through ambient vibrations, which usually allows the proper identification of modal properties, natural frequencies, damping and modes of vibration. Changes in these modal properties constitute an indication of structural damage, which may then be assessed on the basis of experimental evidence. The authors proposed an approach to determine the so-called damage damping and stiffness matrices, which are essential to identify the location and intensity of damage. No restrictions were introduced on the damping matrix of the system. The approach requires ambient vibration data of all relevant coordinates used in the structural model, which are processed employing the SSI method. In practice, the identification method is seriously hampered by ambient factors such as temperature or humidity. In general those effects must be filtered out in other to obtain a reliable diagnosis of damage, approach that demands long term monitoring. In this paper, an alternative approach is explored, based on the introduction of error damping and stiffness matrices. Data on both matrices is generated on the basis of observed variations of structural member stiffness and damping caused by ambient factors. The influence of this uncertainty on the identified spectral properties is assessed by simulation. 展开更多
关键词 IDENTIFICATION damage detection structural monitoring ambient vibrations.
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Automatic authentication using rough set-based technique and fuzzy decision
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作者 陈宁 冯博琴 +1 位作者 王海笑 张浩 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2009年第2期247-250,共4页
This study introduced an automatic authentication technique for checking the genuineness of a vehicle. The rough set-based technique was used to handle the uncertainty arisen from artifacts in the acquired images impr... This study introduced an automatic authentication technique for checking the genuineness of a vehicle. The rough set-based technique was used to handle the uncertainty arisen from artifacts in the acquired images imprinted on a vehicle. However, it has been proved to be NP-hard to find all reductions and the minimal reduction, and generally different heuristic algorithms were used to find a set of reductions and the Ganssian distribution was used to describe the uncertainty to achieve the minimal reduction. On the basis of inductive logic programming, the technique can distinguish between two similar images, as is superior to the conventional pattern-recognition technique being merely capable of classifier. Furthermore, it can avoid some failures of the technique based on the correlation coefficient to authenticate binary image. The experiments show an accuracy rate close to 93. 2%. 展开更多
关键词 E-GOVERNMENT UNCERTAINTY automatic authentication rough set
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