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双语推荐:诊断特征

单独提取滚动轴承振动信号的时域或频域特征进行故障诊断,是目前常用的轴承诊断方法,诊断精度有待提高。以时域和频域的多维振动特征参量为指标,以历史诊断正确率作为特征参量权值,分别对滚动轴承的无故障和经常出现的滚珠故障、内环故障和外环故障工况进行特征提取和故障识别。多维时频域振动特征是单维特征依据诊断精度权重的集合。运用BP神经网络分别对信号的时域特征(TDF)、IMF能量矩(IEM)、小波包能量矩(WPEM),以及多维时频域特征进行智能故障判别。实验验证用多维时频域振动特征参量综合诊断的方法进行滚动轴承故障诊断,比单维特征诊断结果精确且效率较高,该方法可以在滚动轴承故障诊断领域展开应用。
Extracting the time-domain or the frequency-domain features of vibration signals for analysis is a conventional method for rolling bearings fault diagnosis. But the effects of this diagnosis method need to be improved. In this paper, taking the multi-dimensional vibration characteristic parameters in time-domain and frequency-domain as the indexes and the correctness rate of historical diagnosis as the parametric weight, the features of fault-free rolling bearings and the features of rolling bearings with ball fault, inner and outer race faults are extracted and the faults are identified. It shows that the multi-dimensional vibration characteristic in time-frequency domains is the assemblage of single features. BP neural network is used for intelligent fault classification of signals according to the time-domain feature (TDF) parameters, IMF energy moment (IEM), wavelet package energy moment (WPEM) and multi-dimensional features respectively. Results of the diagnoses are compared one a

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为提高网络故障诊断系统的诊断精度,节约计算资源,针对需要处理的含有大量无关或冗余特征的数据,提出了一种基于杂交BPSO-SVM的网络故障特征选择算法.该算法采用封装器模式,以SVM的分类准确率和特征压缩比作为适应度函数来指导杂BPSO进行特征选择,将选择出的最优特征子集用于故障诊断.运用Kdd’99数据集的实验结果表明,杂交BPSO-SVM提高了诊断精度,降低了特征维数,可进一步提升网络故障诊断效果.
In allusion to deal with data which contains a lot of irrelevant and redundant features .A breeding binary particle swarm optimization -support vector machines (BPSO-SVM) algorithm was proposed for feature selection . In order to improve diagnosis accuracy and save computing resources of the network fault diagnosis system .The algorithm adopts w rapper mode ,the classification accuracy of SVM and feature compression ratio as fitness function guide the breeding BPSO algorithm to search the feature space .Finally the best fitness subset was selected out . Experimental result on KDD’99 shows that the advanced algorithm improve the accuracy of diagnosis and reduce the feature dimension ,and can further enhance network fault diagnosis effect .

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先前研究者普遍认为,类别推理学习条件下可以同时表征诊断性信息和非诊断性信息,而类别分类学习条件下中只能表征诊断性信息,不能表征非诊断性信息。而最近又有研究者发现部分呈现条件下的类别分类学习可以表征非诊断性信息。本研究通过两个实验系统比较了全部呈现和部分呈现条件下类别分类学习的结果,进一步探讨了分类学习条件下信息的表征情况,并进一步探讨了部分呈现条件下的分类学习能够表征非诊断性信息的原因。实验1发现全部呈现6个特征、缺失1个特征(即部分呈现5个特征)、缺失2个特征(即部分呈现4个特征)3种条件下都能表征诊断性信息,但只有部分呈现条件下能表征非诊断性信息。实验2发现全部呈现7个特征、缺失2个特征(即部分呈现5个特征)、全部呈现5个特征3种条件下都能表征诊断性信息,但只有部分呈现条件下能表征非诊断性信息。总的实验结果表明:全部呈现条件下的分类学习只能表征诊断性信息,而部分呈现条件下的分类学习能够同时表征诊断性信息和非诊断性信息,并且部分呈现条件下表征非诊断性信息的原因是被试进行了推理学习,而非注意广度的变化。
Previous researches have showed that category learning by inference way can represent diagnostic information and nondiagnostic information, but learning by classifying way only can represent diagnostic information such as exemplar features information. However, recently studies show that learning partial exemplars by classifying also can represent nondiagnostic information ( Taylor & Ross, 2009). Taylor & Ross (2009) offered an explanation of selective attention that there are comparably loose of attention resources in partial condition than entire condition. They left out the possibility that the subject might inference the missing features in the partial condition. In the real world, exemplars often appear with occluded features, but in laboratory research, they are almost always presented in their entirety. Two experiments were conducted to explore how partial classification leads to nondiagnostic features learning. Experiment 1 replicated the Taylor & Ross (2009) finding that learn

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目的:探讨急性阑尾炎的超声影像学特征,应用价值,提高超声诊断符合率。方法回顾性分析我院2013年9月~2014年9月以来,临床诊断为急性阑尾炎并进行阑尾切除的病例,分析其术前的超声影像学特征,并与手术病理诊断进行对比分析。结果42例患者超声诊断39例,超声诊断符合率92.8%,3例不典型。结论不同病理类型的急性阑尾炎超声图像具有一定特征。尤其是高频超声的使用,可根据阑尾炎各型声像图特征,做出较准确的诊断
Objective To investigate the characteristics of ultrasound imaging of acute appendicitis,application value,improve the coincidence rate of ultrasound diagnosis. Methods Retrospective analysis of our hospital from 2013 September to 2014 since September,the clinical diagnosis of acute appendicitis and appendectomy cases,ultrasonographic features of preoperative analysis,and the results were compared with operation and pathology. Results Of 42 cases,39 cases were diagnosed with ultrasound,the diagnostic rate of ultrasound was 92.8%,3 cases of atypical. Conclusion There is some characteristics of acute appendicitis ultrasound images of different pathological types.Especially the use of high-frequency ultrasound in appendicitis,according to the characteristics of ultrasonic images,make more accurate diagnosis.

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为了提高汽轮机故障诊断的精确性,文章运用转子振动实验台来模拟汽轮机转子的振动信号,对运行中的三种故障振动信号进行采集,然后运用局部特征尺度分解方法对汽轮机振动信号时间序列进行特征提取,组成特征向量。利用极限学习机作为故障诊断分类器,结果表明,局部特征尺度分解特征提取和极限学习机的诊断模型能够准确地对汽轮机故障进行诊断,具有很高的实际应用意义。
In order to improve the accuracy of fault diagnosis of steam turbine, this paper was used rotor vibration test bench to simulate the vibration signals of the steam turbine rotor, the operation of three kinds of fault vibration signal acquisition, and then using local characteristic scale decomposition approach to feature extraction steam turbine vibration signal time series of feature vector. Extreme learning machine was taken as a classifier of fault diagnosis. The results showed that the local characteristics of the scale decomposition of feature extraction and extreme learning machine diagnosis model can accurately the fault diagnosis for steam turbine, which had high practical application significance.

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孤立性肺结节诊断模型中未得到充分解决的一个关键问题就是如何选择合适的特征子集。为了构建一个良好的诊断预测模型,提高肺结节良恶性诊断的效率以及准确率,提出了一种基于联合互信息的混合模型特征子集选择算法。该算法综合过滤式和包裹式特征选择模型各自的优势,首先使用过滤式方法得到与诊断有高相关度的候选特征子集,然后通过包裹式方法对候选特征子集进行特征间冗余分析,最后得到最优特征子集。实验表明,该算法与基于其他互信息的过滤式、混合模型特征选择方法相比,不仅在特征子集数目上,而且在良恶性诊断的敏感性、特异性和平均分类准确率上,均具有很好的性能效果。
It is a key problem that how to choose an appropriate feature subset in solitary pulmonary nodules diagnosis model.A hybrid model feature subset selection algorithm is proposed to improve the pulmonary nodules diagnosis efficiency and accuracy of benign or malignant,based on joint mutual information.It takes advantages of both filter and wrapper model.Firstly,a filter method is applied to obtain a candidate subset with high correlation.Then,a wrapper method is used to analyze the redundancy between features of the candidate subset.Finally,an optimal feature subset of solitary pulmonary nodules is achieved.Compared with other filter or hybrid feature selection algorithms based on mutual information,the performance of proposed method is better not only on the number of feature subset,but also on the sensitivity,specificity and the average classification accuracy in solitary pulmonary nodules diagnosis.
特征信息提取作为电力电子电路故障诊断的重要环节,直接影响到诊断结果的有效性。阐述了目前常用的各种故障诊断提取方法,结合实际应用对各个方法进行了优缺点评价。在此基础上,提出了未来特征提取方法的新思路,即构造能够发挥各自优点,实现功能互补的特征提取方法,为进一步提高故障诊断的准确性提供参考。
Feature information extraction, which directly influences the validity of diagnosis result, is an important link in power electronic circuit fault diagnosis. This paper summarized some methods of fault feature extraction in common use and evaluated the advantages and disad-vantages of each method with the combination of practical application. On the basis of this, this paper proposed a new idea for future feature ex-traction methods, which constructed the feature extraction method to bring each advantage into play and to realize the complementary function, to provide reference for further improving the accuracy of fault diagnosis.

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目的:对卵巢良恶性肿瘤的MRI特征及鉴别诊断效果进行研究与分析。方法选取我院收治的100例卵巢肿瘤患者通过MRI技术对卵巢肿瘤进行综合分析,对MRI技术特征以及鉴别诊断效果进行研究。结果共检测出110个病灶,两例误诊,诊断确诊率为98.18%。结论对于卵巢肿瘤的诊断采用MRI技术有显著的诊断效果,良恶性卵巢肿瘤的MRI特征不同,对鉴别诊断也起到了一定帮助。
Objective MRI features and differential diagnosis of benign and malignant ovarian effects were studied and analyzed.Methods Select 100 cases of ovarian cancer patients diagnosed by MRI techniques with ovarian tumors in our hospital, comprehensive analysis of the technical features and MRI to study the effect of the differential diagnosis.Results 110 lesions were detected, two cases of misdiagnosis, diagnosis conifrmed rate was 98.18%. Conclusion For the diagnosis of ovarian cancer, using MRI technology has signiifcant diagnostic results, different MRI features of benign and malignant ovarian tumors, differential diagnosis also played a certain help, worthy clinic.

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为了提高模拟电路故障诊断准确率,提出一种联合选择特征选和分类器参数模型的模拟电路故障诊断方法 (Feature-Classifier)。将模拟电路故障特征子集和分类器参数编码成为粒子,然后粒子根据目标函数通过信息交流和互相协作找到最优特征子集和分类器参数,并根据最优特征子集对样本进行约简;分类器根据最优参数对约简后样本进行训练建立模拟电路故障诊断模型,并通过仿真实例对性能进行测试。结果表明,相对于其他模拟电路故障诊断方法,Feature-Classifier能够较快找到最优特征子集与分类器参数,不仅提高了模拟电路故障诊断准确率,并加快了故障诊断速度。
In order to improve fault diagnosis rate of analog circuits, this paper proposes a fault diagnosis method based on jointly selection features and classifier parameters model. The features and classifier parameters are encoded as a particle, and then, the optimal features and classifier parameters are obtained by the particle swarm optimization algorithm according to objection function, and the samples are reduced on the optimal features. Finally, the samples are input into the classifier to train and build the fault diagnosis model of analog circuits with the optimal parameters, and the simulation experiments are carried out to test the performance of the model. The results show that the proposed method can select the optimal features and classifier parameters quickly to improve the fault diagnosis rate of analog circuits and fasten the speed of the fault diagnosis compared with other methods.

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结合可视化技术和隐马尔可夫模型,提出一种基于可视化重心特征提取的轴承故障诊断新模型。首先,将轴承多维音频数据表示为雷达图的形式,再从雷达图中提取可视化的重心特征;然后,将重心特征进行可视化绘制的同时送入HMM分类器进行故障诊断,实现了可视化诊断和自动诊断2种诊断方式。试验结果表明,该方法不仅能够直观显示轴承信号,而且诊断精度可达97%,平均诊断时间为0.08 s。
A new method of bearing fault diagnosis based on barycenter feature of visualization is presented,combined with visualization and Continuous Gaussian Mixture Hidden Markov Model (HMM).Firstly,the acoustic signal of bearing is showed in radar chart,from which barycenter feature can be exacted;then barycenter feature is visually drawn and sent to HMM classifier for fault diagnosing simultaneously,so as to achieve two diagnosis modes:visual di-agnosis and automatic diagnosis.The result of experiments shows this new method could not only show bearing signal visually,but also has higher diagnosis accuracy (97%)and faster calculating speed (the average time of diagnosis is 0.08 s).

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