首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 734 毫秒
1.
针对油田抽油机生产数据存在强非线性和强耦合性, 导致故障诊断困难的问题, 本文提出一种全相关动态 核偏最小二乘(FCDKPLS)故障诊断方法. 首先, 构建抽油机生产数据自回归模型, 反映数据变量间的动态特性; 其 次, 分析了KPLS算法中输出变量与输入变量残差子空间的相关性, 为此, 在输出模型上构建一个辅助矩阵, 从而表 征输入变量与输出变量的全相关性, 建立输入变量和输出变量之间更直接的联系. 最后, 将提出的全相关动态偏最 小二乘方法应用于抽油机过程故障诊断, 实验结果表明本文提出方法的有效性.  相似文献   

2.
何杜博  孙胜祥  梁新  谢力  张侃 《控制与决策》2024,39(7):2295-2304
针对多目标回归中的特征选择问题,提出一种基于自适应图学习的多目标特征选择算法,在单个框架中同时考虑3种关系结构:输入特征与目标输出、不同目标输出以及样本间的相关结构,并基于上述结构信息进行特征选择.首先,在传统稀疏回归模型中对系数矩阵施加低秩约束,利用低秩学习对特征间相关性以及目标间的依赖关系进行解耦学习;然后,构建基于样本局部结构信息的自适应图学习项,充分利用样本间的相似结构进行特征选择;进一步地,引入基于输出相关性的结构矩阵优化项,使模型能够更加充分地考虑目标间的相关性;最后,提出一种交替优化算法求解目标函数,并从理论上证明算法的收敛性.在公开数据集上的实验表明,所提方法相较于现有主流的多目标特征选择方法具有更好的性能和适用性.  相似文献   

3.
曹玉苹  黄琳哲  田学民 《自动化学报》2015,41(12):2072-2080
传统基于典型变量分析的过程监控方法无法判断故障是否影响产 品质量.为此,本文提出一种基于动态输入输出典型变量分析(Dynamic input-output canonical variate analysis, DIOCVA)的过程监控方法.该方法利用典型变量分析提取数据之间的相关性,并进一步考虑方差信息和时序相关性, 将过程数据和质量数据映射到5个子空间:输入输出相关子空间,不相关输入主元子空间, 不相关输入残差子空间,不相关输出主元子空间和不相关输出残差 子空间.所提方法能够精细区分影响质量的过程故障和不影响质量的过程故障.以Tennessee Eastman过程为例对所提方法的有效性进行了验证.  相似文献   

4.
作为钢铁冶金制造的核心工序, 高炉炼铁是典型的高能耗过程, 其运行能耗约占钢铁总能耗的50%以上, 其中, 80%的能耗是焦炭和煤粉等燃料消耗. 因此, 对表征高炉燃料消耗的燃料比参数进行监测, 并尽可能早地识别影响燃料比异常波动的关键因素, 对于高炉炼铁过程的节能降耗具有重要意义. 本文针对先验故障知识少的高炉燃料比监测与异常识别难题, 提出一种基于核偏最小二乘(Kernel partial least squares, KPLS)鲁棒重构误差的故障识别方法. 该方法首先建立过程变量与监测变量的KPLS监测模型, 然后根据非线性映射空间的协方差矩阵和核空间Gram矩阵之间的关系, 反向估计原始空间变量的正常估值. 为了增强算法的鲁棒性, 采用迭代去噪算法减少异常数据对原始空间正常估值的影响. 通过利用原始空间正常估值和真实值来构造故障识别指标, 并给出故障识别指标的控制限. 基于实际工业数据的高炉数据实验表明所提方法不仅可以监测出正常工况下影响燃料比异常变化的潜在因素, 还可识别出异常工况下影响燃料比异常变化的关键因素, 具有很好的工程应用前景.  相似文献   

5.
张瑞垚  周平 《自动化学报》2022,48(9):2198-2211
针对非线性强、先验故障知识少、异常工况识别难的污水处理过程监测问题,提出一种基于鲁棒加权模糊c均值(Robust weighted fuzzy c-means, RoW-FCM)聚类与核偏最小二乘(Kernel partial least squares, KPLS)的过程监测方法.首先,针对污水处理过程的高维非线性耦合特性,采用核偏最小二乘对高维输入变量进行降维;其次,针对传统基于最近邻分配的模糊c均值算法对离群点敏感以及存在聚类不平衡簇的问题,提出充分考虑样本间相互关系的基于鲁棒加权模糊c均值聚类算法.通过引入可能性划分矩阵作为权值参数实现不同样本数据的区分加权,提高了离群点数据聚类的鲁棒性,同时引入聚类大小控制参数解决不平衡簇的问题.进一步将基于鲁棒加权模糊c均值算法对核偏最小二乘降维后的得分矩阵进行聚类,利用聚类得到的隶属度矩阵实现异常工况的检测;最后,建立隶属度矩阵与过程变量的回归模型,并利用得到的变量贡献矩阵描述变量对各个簇的解释程度,实现异常工况的识别.数值仿真以及污水处理过程数据实验表明该方法具有更好的鲁棒性能,在异常工况检测和识别上具有较好的效果.  相似文献   

6.
随着越来越多多模态数据的出现,跨模态检索引起了广泛的关注。跨模态检索面临一大挑战为模态鸿沟,为了解决数据的异构性问题,公共子空间学习的方法被提出。然而,大部分方法仅仅是单独考虑了样本之间的相关联信息或不相关信息,而没有同时考虑样本间的相关信息和不相关信息。除此之外,大部分方法对于样本之间相似度的比较,使用的是基于文档对的排序比较,其没有充分考虑样本之间的类内依赖性和类间样本的结构差异性。基于此,提出了一种同时而不是单独考虑样本间的类内关系和类间关系的基于列表排序的跨模态检索方法,其通过列表排序最大化锚点与正样本之间的相似性,同时最小化锚点和负样本间的相似性。实验结果验证了该算法在跨模态检索中的有效性。  相似文献   

7.
提出了一种适用于无线传感器网络WSN的故障检测方法,该方法运用改进的递归神经网络MRNN为WSN的节点、节点的动态特性以及节点间的关系建立相关模型,对WSN节点进行识别和故障检测。MRNN的输入选择建模节点的先前输出值及其邻居节点的当前及先前输出值,模型基于一种新的改进的反向传播型神经网络,该神经网络的输入以及传感器网络的拓扑结构基于通用的非线性传感器模型。仿真实验将MRNN方法与卡尔曼滤波法进行了全面的比较。实验表明,MRNN在置信因子较小的情况下与卡尔曼滤波方法相比有较高的故障检测精度。  相似文献   

8.
高效潜结构投影(EPLS)算法是一种反映过程变量与质量变量相关关系的多变量统计分析方法,在质量相关故障检测中具有良好的检测效果.然而EPLS算法是一种静态检测模型,不能反映实际工业过程或装备测试中的动态特性,对动态过程中质量相关故障的检测率较低.为此,本文提出了一种基于自回归移动平均模型(ARMAX)的动态高效潜结构投影(D–EPLS)检测算法.该算法首先基于输入时滞值构建增广矩阵,反映工业以及装备测试过程中的动态特性;然后将增广矩阵分解为质量相关和质量无关空间分别进行故障检测;最后通过数值仿真和田纳西伊斯曼过程(TEP)验证算法有效性.实验结果表明所提算法能够更好的适应动态过程,并全面提高了质量相关故障的检测率.  相似文献   

9.
针对一类具有输入及输出端扰动的T-S模糊系统, 在线性矩阵不等式区域内定义了非线性系统的稳态及动态广义性能指标, 提出了线性矩阵不等式(LMI)方法下可靠输出反馈控制器存在的充分条件, 从而保证闭环系统在传感器或执行器发生结构性故障时的稳态及动态性能, 且始终满足基于L2/L1范数理论的鲁棒性能, 并利用投射引理引入附加阵, 解耦该充分条件中的控制器变量与相关Lyapunov函数变量, 增加设计的自由度. F–16歼击机的纵向通道控制仿真表明了方法的有效性.  相似文献   

10.
时瑞研  潘立登 《控制工程》2003,10(6):506-508,535
在实际生产过程中,过程变量之间往往存在大量相关关系,甚至非线性相关关系。过程变量间存在线性相关时,可采用偏最小二乘方法(Partial Least Squares,PLS)计算模型参数,但由于PLS方法采用线性关系来联系输入和输出因子,因而并不能有效地应用于非线性较强的过程。在这种情况下要对变量进行有效的压缩维数.需要采用非线性PLS方法。基于Chebyshev多项式改进的多元多项式PLS方法,是一种新的非线性PLS方法。该方法利用Chebyshev多项式的正交性质和递推性质,将过程输入变量正交化、线性化后,再应用PLS方法计算模型参数并还原,从而得到比较精确的模型。由于该方法综合考虑了输入变量的自相关和输入变量间的协相关关系。能够更有效地表达过程变量间的非线性关系,因此其对非线性过程的研究提供了新的思路。  相似文献   

11.
Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.  相似文献   

12.
European Community policy and the market   总被引:1,自引:0,他引:1  
Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.  相似文献   

13.
融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。  相似文献   

14.
为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.  相似文献   

15.
Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.  相似文献   

16.
This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.  相似文献   

17.
Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008  相似文献   

18.
In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.  相似文献   

19.
Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.  相似文献   

20.
《Information & Management》2016,53(6):787-802
Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号