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Experts' Knowledge Fusion in Model-Based Diagnosis Based on Bayes Networks 被引量:5
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作者 Deng Yong & Shi Wenkang School of Electronics & Information Technology, Shanghai Jiaotong University, Shanghai 200030, P. R. China 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2003年第2期25-30,共6页
In previous researches on a model-based diagnostic system, the components are assumed mutually independent. Howerver , the assumption is not always the case because the information about whether a component is faulty ... In previous researches on a model-based diagnostic system, the components are assumed mutually independent. Howerver , the assumption is not always the case because the information about whether a component is faulty or not usually influences our knowledge about other components. Some experts may draw such a conclusion that 'if component m 1 is faulty, then component m 2 may be faulty too'. How can we use this experts' knowledge to aid the diagnosis? Based on Kohlas's probabilistic assumption-based reasoning method, we use Bayes networks to solve this problem. We calculate the posterior fault probability of the components in the observation state. The result is reasonable and reflects the effectiveness of the experts' knowledge. 展开更多
关键词 Model-based diagnosis Experts' knowledge Probabilistic assumption-based reasoning bayes networks.
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Activities of daily living and lesion position among multiple sclerosis patients by Bayes network
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作者 Zhifang Pan Hongtao Lu Qi Cheng 《Neural Regeneration Research》 SCIE CAS CSCD 2013年第14期1327-1336,共10页
Magnetic resonance imaging is a highly sensitive approach for diagnosis of multiple sclerosis, and T2-weighted images can reveal lesions in the cerebral white matter, gray matter, and spinal cord. However, the lesions... Magnetic resonance imaging is a highly sensitive approach for diagnosis of multiple sclerosis, and T2-weighted images can reveal lesions in the cerebral white matter, gray matter, and spinal cord. However, the lesions have a poor correlation with measurable clinical disability. In this study, we performed a large-scale epidemiological survey of 238 patients with multiple sclerosis in eleven districts by network member hospitals in Shanghai, China within 1 year. The involved patients were scanned for position and size of lesions by MRI. Results showed that lesions in the cerebrum, spina cord, or supratentorial position had an impact on the activities of daily living in multiple sclerosis patients, as assessed by the Bayes network. On the other hand, brainstem lesions were very unlikely to influence the activities of daily living, and were not associated with the position of lesion, patient's gender, and patient's living place. 展开更多
关键词 neural regeneration neurodegenerative diseases multiple sclerosis magnetic resonance imaging bayes network activities of daily living epidemiological survey grants-supported paper NEUROREGENERATION
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基于Bayes network含失效节点的网络可靠性评估 被引量:4
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作者 李振 孙新利 +1 位作者 姬国勋 刘志勇 《系统工程理论与实践》 EI CSSCI CSCD 北大核心 2011年第10期1974-1984,共11页
针对Bayes network(BN)能很好地表示变量的不确定性和相关性,并能直接进行不确定性推理的优势,提出了基于BN含失效节点的网络可靠性评估方法.建模方面,给出了通过节点分割去环构建有向无环图及条件概率表的具体方法;推理方面,通过节点消... 针对Bayes network(BN)能很好地表示变量的不确定性和相关性,并能直接进行不确定性推理的优势,提出了基于BN含失效节点的网络可靠性评估方法.建模方面,给出了通过节点分割去环构建有向无环图及条件概率表的具体方法;推理方面,通过节点消隐,减小BN规模,有效降低推理复杂度.分析了算法复杂度,并通过算例证明了算法的有效性和适用性.由于BN建模及推理的灵活性,该方法可研究同时含节点失效、共因失效的网络可靠性,况且通过BN推理除得到网络失效概率和部件重要度外,还可得到网络失效条件下任一部件失效或者共因失效发生的概率,为故障诊断和维护提供指导. 展开更多
关键词 网络可靠性 失效节点 共因失效 bayes netWORK
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Mono-isotope Prediction for Mass Spectra Using Bayes Network 被引量:1
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作者 Hui Li Chunmei Liu +1 位作者 Mugizi Robert Rwebangira Legand Burge 《Tsinghua Science and Technology》 SCIE EI CAS 2014年第6期617-623,共7页
Mass spectrometry is one of the widely utilized important methods to study protein functions and components. The challenge of mono-isotope pattern recognition from large scale protein mass spectral data needs computat... Mass spectrometry is one of the widely utilized important methods to study protein functions and components. The challenge of mono-isotope pattern recognition from large scale protein mass spectral data needs computational algorithms and tools to speed up the analysis and improve the analytic results. We utilized na¨?ve Bayes network as the classifier with the assumption that the selected features are independent to predict monoisotope pattern from mass spectrometry. Mono-isotopes detected from validated theoretical spectra were used as prior information in the Bayes method. Three main features extracted from the dataset were employed as independent variables in our model. The application of the proposed algorithm to public Mo dataset demonstrates that our na¨?ve Bayes classifier is advantageous over existing methods in both accuracy and sensitivity. 展开更多
关键词 bayes network tandem mass spectrum mono-isotope prediction
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基于Bayes推断的交流接触器剩余电寿命预测 被引量:1
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作者 李奎 马典良 +2 位作者 赵成晨 胡博凯 王浩然 《仪器仪表学报》 EI CAS CSCD 北大核心 2024年第1期34-45,共12页
针对交流接触器可靠性开展研究,首先分析交流接触器的电弧侵蚀机理,建立了计及电弧电压及电弧重燃影响的电弧侵蚀模型,根据该模型仿真得到的交流接触器性能退化特征参量变化过程与交流接触器的实际退化规律一致。分析不同工况下性能退... 针对交流接触器可靠性开展研究,首先分析交流接触器的电弧侵蚀机理,建立了计及电弧电压及电弧重燃影响的电弧侵蚀模型,根据该模型仿真得到的交流接触器性能退化特征参量变化过程与交流接触器的实际退化规律一致。分析不同工况下性能退化数据特征,提出了不同工况下先验信息的等效折算方法,解决了不同工况下的先验信息利用问题。建立了基于Bayes推断的交流接触器剩余电寿命预测模型,提高了剩余电寿命预测精度,实现了利用不同工况下性能退化数据对交流接触器进行剩余电寿命预测。在AC-4、AC-3两种工况下进行了交流接触器电寿命仿真分析及实验分析,相对误差均小于5.5%,验证了方法的准确性。 展开更多
关键词 交流接触器 电弧电压 电弧重燃 bayes推断 剩余电寿命
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基于Bayes时空模型分析HIV/AIDS晚发现的时空分布特征及其影响因素
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作者 邵莉 陈继军 +3 位作者 张宇琦 许静 栗果 高文龙 《中山大学学报(医学科学版)》 CAS CSCD 北大核心 2024年第2期243-252,共10页
【目的】旨在分析兰州市HIV/AIDS晚发现的时空聚集性特征及相关影响因素,明确兰州市HIV/AIDS晚发现高风险地区和时间趋势,为兰州市因地制宜地制定HIV/AIDS防治策略措施提供参考依据。【方法】选择兰州市2011-2018年间新报告的成年HIV/A... 【目的】旨在分析兰州市HIV/AIDS晚发现的时空聚集性特征及相关影响因素,明确兰州市HIV/AIDS晚发现高风险地区和时间趋势,为兰州市因地制宜地制定HIV/AIDS防治策略措施提供参考依据。【方法】选择兰州市2011-2018年间新报告的成年HIV/AIDS病例作为研究对象,研究中所需的数据资料来自兰州市疾病预防控制中心和兰州市统计年鉴。采用Bayes时空模型分析HIV/AIDS晚发现相对风险(RR)的时空分布特征及其影响因素。【结果】2011-2018年间兰州市新报告的HIV/AIDS病例共计1984例,其中HIV/AIDS晚发现者有982例(49.5%),平均年龄为39.67岁,男性占90.9%。老年人和女性HIV/AIDS病例中晚发现的比例更高;城关区(51.1%)、安宁区(50.3%)和榆中县(51.9%)具有高于平均水平的HIV/AIDS晚发现比例;2011-2018年间兰州市总体的晚发现比例呈波动上升趋势。Bayes时空模型分析结果显示,兰州市HIV/AIDS晚发现风险在2011-2015年间波动变化,而在2015年后迅速上升,其RR(95%CI)从1.01(0.84,1.23)上升到1.11(0.77,1.97);红古区和三个县的晚发现风险变化趋势与兰州市的总体变化趋势相似,而城关区和七里河区的晚发现风险呈下降趋势;晚发现相对风险大于1的区县包括:永登县(RR=1.07,95%CI:0.55,1.96)、西固区(RR=1.04,95%CI:0.67,1.49)、城关区(RR=2.41,95%CI:0.85,6.16)和七里河区(RR=2.03,95%CI:1.10,3.27)。冷热点分析结果显示城关区和七里河区为热点区。影响因素分析结果显示,随着人均GDP(RR=0.65,95%CI:0.35,0.90)和HIV/AIDS病例中的男性比例(RR=0.53,95%CI:0.19,0.92)的增高,HIV/AIDS晚发现的相对风险越低;而人口密度(RR=1.35,95%CI:1.01,1.81)越大,晚发现风险越高。【结论】兰州市的HIV/AIDS晚发现风险呈上升趋势,并且存在明显的地区差异特征;人均GDP、HIV/AIDS中男性比例和人口密度是HIV/AIDS晚发现的影响因素。因此,对于晚发现风险高和存在相关风险因素的区县,应重视并制定有针对性的HIV筛查和防治服务,降低HIV/AIDS晚发现比例和风险。 展开更多
关键词 艾滋病 人类免疫缺陷病毒 晚发现 bayes时空模型 分布特征
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黄土抗剪强度参数均值与方差的Bayes估计及其应用
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作者 李萍 董鸾花 +3 位作者 赵枝艳 李金明 沈伟 李同录 《建筑科学与工程学报》 CAS 北大核心 2024年第2期163-172,共10页
为解决黄土强度参数估计问题,从工程勘察项目中共收集统计了3384组Q1、Q2、Q3黄土强度参数黏聚力c、内摩擦角φ值的测试数据,不考虑二者的相关性,将参数均值和方差都作为随机变量,建立起黄土强度参数c、φ的正态-逆伽马先验分布。基于Ba... 为解决黄土强度参数估计问题,从工程勘察项目中共收集统计了3384组Q1、Q2、Q3黄土强度参数黏聚力c、内摩擦角φ值的测试数据,不考虑二者的相关性,将参数均值和方差都作为随机变量,建立起黄土强度参数c、φ的正态-逆伽马先验分布。基于Bayes理论,利用共轭先验法推导了参数后验分布和后验概率密度函数的期望值求解公式,确定了估计的误差。以陕西泾阳黄土边坡为例,利用所建立的先验分布和边坡土层测试强度指标,求取参数的后验分布,进一步估计了边坡失效概率的概率分布和稳定系数均值的概率分布。结果表明:在95%的置信度下,按稳定系数评价,边坡均处于基本稳定状态,且稳定系数置信区间小;按失效概率评价,边坡接近稳定状态,但失效概率的置信区间较大,黄土强度参数的方差控制着边坡失效概率的置信区间,将方差作为随机变量,考虑方差变异性,能更科学地评估黄土工程的可靠度。 展开更多
关键词 黄土 边坡 bayes理论 先验分布 正态-逆伽马分布
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Ⅱ型双删失样本下逆Topp-Leone分布的Bayes估计
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作者 习长新 刘华 张玲 《荆楚理工学院学报》 2024年第4期1-9,共9页
在Ⅱ型双删失样本下,研究了逆Topp-Leone分布参数的极大似然估计,证明了极大似然估计的存在性和唯一性;基于未知参数的先验分布为Gamma分布和Jeffrey分布,分别在三种不同损失函数下,得到逆Topp-Leone分布未知参数的Bayes估计。根据后验... 在Ⅱ型双删失样本下,研究了逆Topp-Leone分布参数的极大似然估计,证明了极大似然估计的存在性和唯一性;基于未知参数的先验分布为Gamma分布和Jeffrey分布,分别在三种不同损失函数下,得到逆Topp-Leone分布未知参数的Bayes估计。根据后验密度函数得到预测密度,进而得到未来观测值在三种损失函数下的预测估计值。为了比较在不同损失下Bayes估计的优劣,采用数值模拟方法计算了各种估计的均值及均方误差,结果表明在Linex损失下未知参数的Bayes估计量更接近真值,均方误差最小。 展开更多
关键词 Ⅱ型双删失 逆Topp-Leone分布 bayes估计 预测
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一类Lindley模型参数的经验Bayes检验收敛速度的改进
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作者 黄金超 《吉首大学学报(自然科学版)》 CAS 2024年第3期13-18,共6页
利用递归核估计和单调性,构造了Lindley模型参数的经验Bayes检验函数,并在适当的条件下,证明了收敛速度的阶可任意接近O(n^(-1)).
关键词 Lindley分布族 递归核估计 bayes检验 经验bayes检验 收敛速度
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Improve Computer Visualization of Architecture Based on the Bayesian Network 被引量:1
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作者 Tao Shen Yukari Nagai Chan Gao 《Computers, Materials & Continua》 SCIE EI 2019年第2期307-318,共12页
Computer visualization has marvelous effects when it is applied in various fields,especially in architectural design.As an emerging force in the innovation industry,architects and design agencies have already demonstr... Computer visualization has marvelous effects when it is applied in various fields,especially in architectural design.As an emerging force in the innovation industry,architects and design agencies have already demonstrated the value of architectural visual products in actual application projects.Based on the digital image technology,virtual presentation of future scenes simulates architecture design,architectural renderings and multimedia videos.Therefore,it can help design agencies transform the theoretical design concept into a lively and realistic visual which can provide the audience with a clearer understanding of the engineering and construction projects.However,it is challenging for designers to produce satisfactory renderings due to the frequent fault data during rendering.In this paper,we use the 3Ds MAX as the operating platform and we present an algorithm based on the Bayesian network to construct a vector representation of the fault data.On this basis,a case study of 3D Max’application has also been presented. 展开更多
关键词 3Ds MAX architectural visualization application geometric reconstruction bayes.
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Bayesian Estimation in Dam Monitoring Networks 被引量:1
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作者 Joo Manuel Martins Casaca Pedro Jorge Bele Mateus Joeo de Jesus Isidoro Coelho 《Journal of Civil Engineering and Architecture》 2011年第2期185-190,共6页
A Bayesian estimator with informative prior distributions (a multi-normal and an inverted gamma distribution), adequate to displacement estimation at dam displacement monitoring networks, is presented. The hyper-par... A Bayesian estimator with informative prior distributions (a multi-normal and an inverted gamma distribution), adequate to displacement estimation at dam displacement monitoring networks, is presented. The hyper-parameters of the prior distributions are obtained by Bayesian empirical methods with non-informative meta-priors. The performances of the Bayes estimator and the classical generalized lest squares estimator are compared using two measurements of the horizontal monitoring network of a concrete gravity dam: the Penha Garcia dam (Portugal). In order to test the robustness of the two estimators, a gross error is added to one of the measured horizontal directions: the Bayes estimator proves to be significantly more robust than the classic maximum likelihood estimator. 展开更多
关键词 bayes estimator hyper-parameter parametric elicitation prior distribution.
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Social Network Rumor Recognition Based on Enhanced Naive Bayes 被引量:1
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作者 Lei Guo 《Journal of New Media》 2021年第3期99-107,共9页
In recent years,with the increasing popularity of social networks,rumors have become more common.At present,the solution to rumors in social networks is mainly through media censorship and manual reporting,but this me... In recent years,with the increasing popularity of social networks,rumors have become more common.At present,the solution to rumors in social networks is mainly through media censorship and manual reporting,but this method requires a lot of manpower and material resources,and the cost is relatively high.Therefore,research on the characteristics of rumors and automatic identification and classification of network message text is of great significance.This paper uses the Naive Bayes algorithm combined with Laplacian smoothing to identify rumors in social network texts.The first is to segment the text and remove the stop words after the word segmentation is completed.Because of the data-sensitive nature of Naive Bayes,this paper performs text preprocessing on the input data.Then a naive Bayes classifier is constructed,and the Laplacian smoothing method is introduced to solve the problem of using the naive Bayes model to estimate the zero probability in rumor recognition.Finally,experiments show that the Naive Bayes algorithm combined with Laplace smoothing can effectively improve the accuracy of rumor recognition. 展开更多
关键词 Rumor recognition social network machine learning naive bayes laplacian smoothing
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核主泵机械密封可靠性Bayes分析的适应性
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作者 高灯 孙见君 张玉言 《润滑与密封》 CAS CSCD 北大核心 2024年第2期155-161,共7页
机械密封的可靠性对核主泵的安全稳定运行具有重要影响。为解决无失效数据情形下核主泵机械密封的可靠度评估问题,分析大亚湾核主泵机械密封的运行数据,确定其可靠度分布,建立结合Bayes理论的可靠性分析模型,利用Monte Carlo法从确定的... 机械密封的可靠性对核主泵的安全稳定运行具有重要影响。为解决无失效数据情形下核主泵机械密封的可靠度评估问题,分析大亚湾核主泵机械密封的运行数据,确定其可靠度分布,建立结合Bayes理论的可靠性分析模型,利用Monte Carlo法从确定的可靠度分布中仿真出无失效数据,探讨无失效数据场合下,先验分布为Beta分布时,分组数c的取值对E-Bayes估计与多层Bayes估计精度的影响。研究表明:分组数c<8时,优先选择多层Bayes估计;c>8,优先选择E-Bayes估计,c=8时,2种方法的平均相对误差均达到较低水平且多层Bayes估计更低一些。研究成果对无失效数据场合下基于Bayes理论的核主泵机械密封可靠性分析具有指导意义。 展开更多
关键词 无失效数据 bayes理论 核主泵 机械密封 可靠性
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偏态分布截断参数的经验Bayes检验
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作者 刘蕊 谭燕 吴刘仓 《高校应用数学学报(A辑)》 北大核心 2024年第1期13-27,共15页
偏态分布是对称分布的一种推广,在实际生活中应用广泛,其中截断参数对界定偏态分布的边界具有重要意义.文中基于经验Bayes检验方法,研究了偏态分布截断参数的假设检验问题.考虑普通Bayes检验中先验密度的未知性和不确定性,利用递归核估... 偏态分布是对称分布的一种推广,在实际生活中应用广泛,其中截断参数对界定偏态分布的边界具有重要意义.文中基于经验Bayes检验方法,研究了偏态分布截断参数的假设检验问题.考虑普通Bayes检验中先验密度的未知性和不确定性,利用递归核估计的密度函数代替未知的先验密度函数.定义检验的加权线性损失函数,从而更好地刻画了决策风险.在给定条件下证明了所提出检验函数的渐近最优性,同时给出确定的收敛速度.最后通过实例验证了文中的理论结果. 展开更多
关键词 经验bayes检验 偏态分布 递归核估计 渐近最优性 收敛速度
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Bayes推断和神经网络求解美式回望期权的隐含波动率
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作者 陶李 朱本喜 +1 位作者 钱译缘 徐嘉琪 《吉林大学学报(理学版)》 CAS 北大核心 2024年第6期1363-1369,共7页
首先,用原始对偶活跃集方法求解期权定价正问题,将相应的数值解作为监督学习的输出,然后用训练好的神经网络替代期权定价正问题模型.其次,结合Bayes推断与神经网络进行Metropolis-Hastings采样,求解隐含波动率反问题.该方法减少了采样... 首先,用原始对偶活跃集方法求解期权定价正问题,将相应的数值解作为监督学习的输出,然后用训练好的神经网络替代期权定价正问题模型.其次,结合Bayes推断与神经网络进行Metropolis-Hastings采样,求解隐含波动率反问题.该方法减少了采样过程中正问题计算量庞大的问题,从而加速了反问题求解过程. 展开更多
关键词 隐含波动率 bayes推断 神经网络 替代模型
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FLBS: Fuzzy lion Bayes system for intrusion detection in wireless communication network
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作者 NARENDRASINH B Gohil VDEVYAS Dwivedi 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第11期3017-3033,共17页
An important problem in wireless communication networks (WCNs) is that they have a minimum number of resources, which leads to high-security threats. An approach to find and detect the attacks is the intrusion detecti... An important problem in wireless communication networks (WCNs) is that they have a minimum number of resources, which leads to high-security threats. An approach to find and detect the attacks is the intrusion detection system (IDS). In this paper, the fuzzy lion Bayes system (FLBS) is proposed for intrusion detection mechanism. Initially, the data set is grouped into a number of clusters by the fuzzy clustering algorithm. Here, the Naive Bayes classifier is integrated with the lion optimization algorithm and the new lion naive Bayes (LNB) is created for optimally generating the probability measures. Then, the LNB model is applied to each data group, and the aggregated data is generated. After generating the aggregated data, the LNB model is applied to the aggregated data, and the abnormal nodes are identified based on the posterior probability function. The performance of the proposed FLBS system is evaluated using the KDD Cup 99 data and the comparative analysis is performed by the existing methods for the evaluation metrics accuracy and false acceptance rate (FAR). From the experimental results, it can be shown that the proposed system has the maximum performance, which shows the effectiveness of the proposed system in the intrusion detection. 展开更多
关键词 intrusion detection wireless communication network fuzzy clustering naive bayes classifier lion naive bayes system
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无失效威布尔情形下基于双修正多层Bayes的可靠性评估
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作者 龙足腾 郑波 +1 位作者 甯洋 罗金超 《工程设计学报》 CSCD 北大核心 2024年第1期59-66,共8页
利用配分布曲线法构建无失效数据的可靠性评估模型时,往往采用E-Bayes或多层Bayes来估计失效概率,但因其估计能力有限,整体可靠度点估计精度不高。针对威布尔分布数据提出了一种新的双修正多层Bayes方法,用于改善失效概率估计,并完成可... 利用配分布曲线法构建无失效数据的可靠性评估模型时,往往采用E-Bayes或多层Bayes来估计失效概率,但因其估计能力有限,整体可靠度点估计精度不高。针对威布尔分布数据提出了一种新的双修正多层Bayes方法,用于改善失效概率估计,并完成可靠度点估计。在多层Bayes的基础上,通过修正失效概率上下限值来减小失效概率估计误差,然后结合加权最小二乘法和威布尔分布可靠度函数确定参数估计值和可靠度曲线,从而得到可靠度点估计。利用Monte-Carlo仿真试验,发现新方法能将参数估计相对误差控制在10%以下,并且得到的可靠度值更加趋近真值。通过实例分析发现,在超参数c取不同值的情况下,采用新方法得到的可靠度都更加接近工程实际。新方法适用性分析表明,形状参数β是影响估计精度的关键因素,且在β>2.2时新方法具有明显的优势及良好的稳健性。研究结果可为其他寿命分布无失效数据的可靠性评估提供参考。 展开更多
关键词 无失效威布尔 失效概率估计 双修正多层bayes 可靠度估计 适用性分析
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不同环境下含零失效数据的系统可靠性Bayes评估方法
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作者 唐庆 郝威巍 +1 位作者 孔祥睿 孙永全 《黑龙江大学自然科学学报》 CAS 2024年第1期28-37,共10页
针对船舶装备电子系统在研制阶段经历多种试验,且试验环境应力存在明显差异性及试验过程存在零失效的情况,基于电子系统失效率,提出了零失效情况下环境因子置信区间确定方法,并提出零失效情况下各阶段试验时间及故障数据的折合方式。构... 针对船舶装备电子系统在研制阶段经历多种试验,且试验环境应力存在明显差异性及试验过程存在零失效的情况,基于电子系统失效率,提出了零失效情况下环境因子置信区间确定方法,并提出零失效情况下各阶段试验时间及故障数据的折合方式。构建了电子系统失效率的先验分布模型,利用Bayes方法融合试验信息给出失效率的点估计及置信限,方便后续的可靠性评估。并以某船舶电子系统为例,验证了可靠性评估方法的有效性,为船舶典型装备电子系统可靠性评估提供了参考。 展开更多
关键词 电子系统 零失效 环境因子 bayes可靠性评估
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一种对称损失下逆高斯分布形状参数的Bayes估计
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作者 孙双 徐宝 《南昌大学学报(理科版)》 CAS 2024年第3期205-213,共9页
在加权p、q对称损失下,分别研究了逆高斯分布形状参数的Bayes估计、多层Bayes估计和E-Bayes估计,并把刀切法的思想运用到Bayes估计中,得到逆高斯分布形状参数的刀切Bayes估计的精确形式,为验证形状参数估计的合理性,运用R软件,采用随机... 在加权p、q对称损失下,分别研究了逆高斯分布形状参数的Bayes估计、多层Bayes估计和E-Bayes估计,并把刀切法的思想运用到Bayes估计中,得到逆高斯分布形状参数的刀切Bayes估计的精确形式,为验证形状参数估计的合理性,运用R软件,采用随机游动Metropolis算法对所研究参数的Bayes估计、E-Bayes估计和刀切Bayes估计进行数值模拟,比较了在加权p、q对称损失、Linex非对称损失、平方损失和q-对称损失下逆高斯分布形状参数的Bayes估计的精度,结果表明加权p、q对称损失下逆高斯分布形状参数的Bayes估计的精度最高。 展开更多
关键词 bayes估计 逆高斯分布 刀切法 损失函数 随机游动Metropolis算法
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Linking Structural Equation Modeling with Bayesian Network and Its Application to Coastal Phytoplankton Dynamics in the Bohai Bay
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作者 XU Xiao-fu SUN Jian +2 位作者 NIE Hong-tao YUAN De-kui TAO Jian-hua 《China Ocean Engineering》 SCIE EI CSCD 2016年第5期733-748,共16页
Bayesian networks (BN) have many advantages over other methods in ecological modeling, and have become an increasingly popular modeling tool. However, BN are flawed in regard to building models based on inadequate e... Bayesian networks (BN) have many advantages over other methods in ecological modeling, and have become an increasingly popular modeling tool. However, BN are flawed in regard to building models based on inadequate existing knowledge. To overcome this limitation, we propose a new method that links BN with structural equation modeling (SEM). In this method, SEM is used to improve the model structure for BN. This method was used to simulate coastal phytoplankton dynamics in the Bohai Bay. We demonstrate that this hybrid approach minimizes the need for expert elicitation, generates more reasonable structures for BN models, and increases the BN model's accuracy and reliability. These results suggest that the inclusion of SEM for testing and verifying the theoretical structure during the initial construction stage improves the effectiveness of BN models, especially for complex eco-environment systems. The results also demonstrate that in the Bohai Bay, while phytoplankton biomass has the greatest influence on phytoplankton dynamics, the impact of nutrients on phytoplankton dynamics is larger than the influence of the physical environment in summer. Furthermore, although the Redfield ratio indicates that phosphorus should be the primary nutrient limiting factor, our results show that silicate plays the most important role in regulating phytoplankton dynamics in the Bohai Bay. 展开更多
关键词 structural equation modeling bayesian networks ecological modeling Bohai Bay phytoplankton dynamics
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