共查询到18条相似文献,搜索用时 72 毫秒
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现有基于置信规则库的分类系统的分类准确率和效率受到系统参数设置以及规则库结构合理性的影响。为了寻找到最佳的参数值和最优的规则库结构,本文结合多目标免疫系统算法(multiobjective immune system algorithm, MISA)提出利用MISA多目标优化的置信规则库分类算法。该方法融合特征属性约简思想和差分进化算法思想建立训练模型,采用多目标免疫系统算法对系统复杂度和分类准确率进行多目标优化,从而寻找到分类模型的最优解。在实验分析中,首先将本文提出的置信规则库多目标分类系统MISA-BRM和置信规则库分类系统的实验结果进行对比,从复杂度和准确率两个维度说明本文方法的有效性。同时还将本文方法与现有的其他分类方法进行比较,验证本文方法的可行性和有效性。实验结果表明,本文方法能够有效地对基于置信规则库的分类系统的准确率和复杂度进行多目标优化。 相似文献
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针对扩展置信规则库(extended belief rule base,EBRB)系统在不一致的激活规则过多时推理准确性不高的问题,引入带精英策略的快速非支配排序遗传算法(NSGA-Ⅱ),提出一种基于NSGA-Ⅱ的激活规则多目标优化方法。该方法首先将激活权重大于零的规则(即激活规则)进行二进制编码,把最终参与合成推理的激活规则集合的不一致性以及激活权重和作为多目标优化问题的目标函数,通过带精英策略的快速非支配排序遗传算法求解不一致性更小的激活规则集合,从而降低不一致激活规则对于EBRB系统推理准确性的影响。为了验证本文方法的有效性和可行性,引入非线性函数和输油管道检漏实例进行测试。实验结果表明,基于NSGA-Ⅱ的扩展置信规则库激活规则多目标优化方法能够有效提高EBRB系统的推理能力。 相似文献
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《计算机科学与探索》2016,(5):709-721
通过引入置信规则库的线性组合方式,设定规则数等于分类数及改进个体匹配度的计算方法,提出了基于置信规则库推理的分类方法。比较传统的置信规则库推理方法,新方法中规则数的设置不依赖于问题的前件属性数量或候选值数量,仅与问题的分类数有关,保证了方法对于复杂问题的适用性。实验中,通过差分进化算法对置信规则库的规则权重、前件属性权重、属性候选值和评价等级的置信度进行参数学习,得到最优的参数组合。对3个常用的公共分类数据集进行测试,均获得理想的分类准确率,表明新分类方法合理有效。 相似文献
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针对置信规则中规则数的\"组合爆炸\"问题,目前的解决方法主要是基于特征提取的规则约简方法,有效性依赖于专家知识.鉴于此,提出基于粗糙集理论的无需依赖规则库以外知识的客观方法,按照等价类划分思想逐条分析置信规则,进而消除冗余的候选值.最后,以装甲装备能力评估作为实例进行分析,分别从规则约简数、决策准确性方面与具有代表性的主观方法进行对比,结果表明,所提出方法是有效可行的,且优于现有规则约简主观方法. 相似文献
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基于置信规则库的飞控系统故障诊断 总被引:1,自引:0,他引:1
针对传统飞控系统故障诊断中存在的因引入专家知识引起的主观偏差问题和使用数据驱动方法因数据量不足导致的过拟合问题,提出了基于置信规则库推理的飞控系统故障诊断。根据已有故障知识构建飞控系统故障诊断置信规则库,利用测试过程中获得的故障数据,以数值样本优化学习模型对置信规则库参数进行训练。实例表明,经少量样本训练后的置信规则库可以很好地解决初始置信规则库参数存在主观偏差的问题,经实验证明该方法能够实现高效可靠的飞控系统故障诊断。 相似文献
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出租车乘车概率预测中存在数据量级大,底层属性类型多,预测信息不确定的问题。鉴于此,整合大规模轨迹数据范畴中现有的挖掘算法对出租车GPS数据和路网数据进行离线处理;将多类型的不确定性数据转换为具有置信结构的规则形式,并以此构建置信规则库;通过置信规则库推理方法(belief rule-base infer-ence methodology using evidential reasoning,RIMER)在线预测路网道路上各个地点的乘车概率。以北京市2012年11月某天的出租车GPS数据为例说明该在线预测方法的应用。实验结果表明,该预测方法具有较高的实时性和准确性。 相似文献
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结合加速度计运行机理复杂,测试样本少的特点,提出一种基于置信规则库(BRB)和弹道仿真的健康状态评估模型.首先,基于BRB建立初始的健康状态评估模型,由于定性知识的主观性,初始的评估模型难以提供准确的评估结果而需要被优化,然而,在以往的研究中优化所需的健康状态真实值一般通过专家给定,存在模糊性和不精确的问题,因此,根据加速度计在导航过程中的物理模型,基于弹道仿真方法准确地计算其健康状态的真实值;然后,基于协方差自适应进化算法(P-CMA-ES),健康状态真实值被用于初始评估模型的优化,从而准确、快速地进行健康状态评估;最后,以某型加速度计的健康状态评估为例,验证所提出方法的有效性. 相似文献
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针对置信规则库中初始结构不合理的问题,现有的解决方法仍存在不具备可重复性或受数据完备性和等级效用值相关联的制约等方面的不足。鉴于此,对置信规则库的参数学习进行了理论分析和实验验证,总结出不合理结构下置信规则库中易出现结构欠完备问题或结构过完备问题;将DBSCAN算法和误差分析嵌入到现有参数学习方法中用于解决上述问题,进而提出了面向最佳决策结构的结构学习方法;通过实验分别在过完备结构和欠完备结构的置信规则库下验证了新方法,并对比了结构改变时误差的变化。实验结果表明所提方法是有效可行的。 相似文献
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In this paper, based on belief rule base (BRB), we studied the distributed online fault diagnosis problem of multi-agent systems (MASs). To begin with, considering the distributed nature of MASs, by using the relative information between an agent and its neighbors, a distributed online fault diagnosis model is constructed. Next, for the results of fault diagnosis, when an agent doesn't get enough relative information to diagnose the fault, the fault diagnosis result may be inaccurate, and if there exist too many neighbors of an agent, the number of attributes of the proposed BRB fault diagnosis model will be too large, which will lead to large computation. To improve the performance of the proposed distributed online fault diagnosis model, a real-time communication topology switching strategy was proposed. Under the constructed distributed fault diagnosis model, the real-time performance and the accuracy of fault diagnosis for agents can be guaranteed simultaneously. Finally, a simulation is given to validate the effectiveness and advancement of the distributed online fault diagnosis method proposed in this paper. 相似文献
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Zhichao Feng Wei He Zhijie Zhou Xiaojun Ban Changhua Hu Xiaoxia Han 《IEEE/CAA Journal of Automatica Sinica》2021,8(11):1774-1785
Safety assessment is one of important aspects in health management. In safety assessment for practical systems, three problems exist: lack of observation information, high system complexity and environment interference. Belief rule base with attribute reliability (BRB-r) is an expert system that provides a useful way for dealing with these three problems. In BRB-r, once the input information is unreliable, the reliability of belief rule is influenced, which further influences the accuracy of its output belief degree. On the other hand, when many system characteristics exist, the belief rule combination will explode in BRB-r, and the BRB-r based safety assessment model becomes too complicated to be applied. Thus, in this paper, to balance the complexity and accuracy of the safety assessment model, a new safety assessment model based on BRB-r with considering belief rule reliability is developed for the first time. In the developed model, a new calculation method of the belief rule reliability is proposed with considering both attribute reliability and global ignorance. Moreover, to reduce the influence of uncertainty of expert knowledge, an optimization model for the developed safety assessment model is constructed. A case study of safety assessment of liquefied natural gas (LNG) storage tank is conducted to illustrate the effectiveness of the new developed model. 相似文献
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置信规则库(belief rule base,BRB)的参数训练问题实质上是一个带有约束条件的非线性优化问题,目前在求解该问题上主要使用FMINCON函数及群智能算法,但在算法的应用中存在移植性差,难实现,计算时间长等局限性。通过对这些问题的研究,结合现有的参数训练方法提出了基于加速梯度求法的置信规则库参数训练方法,并将其应用在多峰函数、输油管道泄漏检测的置信规则库的参数训练上。以收敛误差、收敛时间和皮尔森相关系数作为衡量指标,对新方法与其他传统方法进行了对比,实验结果表明,新算法在收敛精度和收敛速度上具有更理想的综合效益。 相似文献
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It is important to establish the forecasting model of the network security situation. But the network security situation cannot be observed directly and can only be measured by other observable data. In this paper the network security situation is considered as a hidden behavior. In order to predict the hidden behavior, some methods have been proposed. However, these methods cannot use the hybrid information that includes qualitative knowledge and quantitative data. As such, a forecasting model of network security situation is proposed on the basis of the hidden belief rule base (BRB) model when the inputs are multidimensional. The initial parameters of the hidden BRB model given by experts may be subjective and inaccurate. In order to train the parameters, a revised covariance matrix adaption evolution strategy (CMA-ES) algorithm is further developed by adding a modified operator. The revised CMA-ES algorithm can optimize the parameters of the hidden BRB model effectively. The case study shows that compared with other methods, the proposed hidden BRB model and the revised CMA-ES algorithm can predict the network security situation effectively to improve the forecasting precision by making full use of qualitative knowledge. 相似文献
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社交账户可信度评估是确保网络社交生态良性发展的重要环节。针对社交账户可信度评估指标多维、数据信息不确定性多样等问题,提出了一种基于改进分层置信规则库的可信度评估方法。首先从账户属性、交际属性和内容属性三个角度分析了可信度评估各指标之间的相互关系,并依此构建了置信规则库的分层结构。其次,在信息转换函数中引入了自适应系数以更好描述和处理指标间的特性差异。最后,为了弥补专家知识局限性带来的模型误差,采用带有投影算子的协方差矩阵自适应进化策略对自适应系数和模型参数进行了优化。以新浪微博账户作为实验对象,结果表明该方法能够在数据样本有限的情况下获得更高的可信度评估精度。 相似文献