共查询到19条相似文献,搜索用时 62 毫秒
1.
2.
爆破振动特征参量的粗糙集模糊神经网络预测 总被引:2,自引:2,他引:2
摘 要 爆破振动特征参量对爆破振动危害效应有重要影响。首次用粗糙集模糊神经网络方法对振幅、主频率及主频持续时间进行预测。首先介绍了粗糙集模糊神经网络的基本思想,其次,分析了印象爆破振动特征参量的主要因素,建立了基于粗糙集模糊神经网络的爆破振动特征参量预测模型;最后用某边坡开挖爆破中的振动观测指标对模型进行了训练,并对15组指标进行了测试。结果表明:粗糙集模糊神经网络预测模型能反映了影响因素与特征量之间的非线性关系,适用于爆破振动特征参量预测。一次预测1个指标的精度高于同时预测3个指标的精度。 相似文献
3.
4.
5.
旋转整流器故障识别是无刷励磁同步电机故障监测的难点之一。针对其故障类型,本文采用Fuzzy模式识别方法,建立计算机数字诊断模型,提高旋转整流器故障识别的准确度。 相似文献
6.
7.
为有效提高滚动轴承故障诊断率,正确识别不同故障类型,提出基于优化K-最近邻域分类器(K-Nearest Neighbor Classifier,KNNC)的轴承故障模式识别方法。分别求得滚动轴承训练样本与测试样本的振动特征指标,构建样本特征集。为加快分类速度,剔除不良样本干扰,利用K-均值聚类算法对样本进行优化精简,并将所得若干聚类中心作为新的约简训练集。据新训练集进行KNNC分析,实现模式识别。结果表明:该方法能快速、有效识别出滚动轴承4种不同故障模式,识别正确率明显提高。 相似文献
8.
9.
10.
控制图模式识别能够区分制造过程中的一般因素与异常因素,提高制造过程中的产品质量,减少成本,提高效益。利用蒙特卡洛方法产生样本;采用一维离散小波变换处理原始数据;利用模糊c均值聚类算法进行控制图模式识别。识别准确率99.43%,其标准差为0.002 8。这表明基于该方法的控制图模式识别准确率高,稳定性好,较现有的控制图模式识别方法具有简易、高效等特点。 相似文献
11.
12.
Kathleen B. Aviso Raymond R. Tan Alvin B. Culaba 《Clean Technologies and Environmental Policy》2008,10(1):53-66
Practical environmental decision-making in industry is a complex task that often entails a subtle interplay between alternatives
and criteria. Quantitative tools are used to aid decision-makers to arrive at rational conclusions. However, conventional
decision aids are often limited by the need to define a priori weights for the criteria being considered; identifying the
correct weights to use is not a trivial task and has been the subject of considerable research. An alternative approach based
on rough set methodology is described in this work. The procedure develops an empirical, rule-based model from example responses
derived from an expert panel. The model can then be used for decision-making in cases resembling the example used previously.
Rough set theory also provides numerical measures of the reliability of the rule-based model developed. The approach is illustrated
with two case studies, the first involving comparison of alternative energy sources, and the second involving the ranking
of pollution prevention strategies in manufacturing. 相似文献
13.
14.
深沟球轴承运转过程动态特性有限元分析 总被引:5,自引:2,他引:5
综合考虑轴承径向载荷及转速的影响,应用ANSYS/LS-DYNA软件建立了深沟球轴承多体动力接触有限元模型;以显式动力学有限元法为基础,采用全积分单元算法控制沙漏,设置质量缩放系数缩减计算时间,对内圈施加不同转速时的深沟球轴承进行动力接触分析,得出了深沟球轴承运转过程的动态响应及滚动体的应力分布。滚动体的最大和最小线速度分别出现在与内、外圈接触点上,各转速下滚动体与内圈接触的应力基本相同,滚动体与外圈接触的应力随转速增高而相应增大,滚动体与外圈间接触力的波动大于内圈,而滚动体与保持架间的作用力较小。研究表明,ANSYS/LS-DYNA是分析轴承运转过程动力接触问题十分有效的工具。 相似文献
15.
轮箍是铁路机车运行的重要部件,在制造和使用过程中出现的各种危害性缺陷会严重威胁到列车的行驶安全.用超声无损检测缺陷,回波的识别易受轮箍标记、闸瓦、轮轨接触点及表面波等多种因素的干扰.在超声横波探伤基础上,可将模糊模式识别应用到机车轮箍的无损检测中.以内燃机车轮箍为实验检测对象,使用了多个标准人工伤模拟轮箍自然缺陷.通过提取缺陷回波频域相关特征建立典型缺陷的模糊子集,并运用基于贴近度的择近原则对未知缺陷进行分类识别.实验结果证明了该方法有效.对同一缺陷重复检测的正确识别率达92.5%. 相似文献
16.
针对复杂噪声环境下识别性能显著降低的问题,提出一种用于说话人识别系统前端的双微阵列语音增强算法。该算法采用的是相干滤波和频域宽带最小方差无畸变响应波束形成器后置结合改进的维纳滤波器。其基本原理是首先求出双微麦克风阵列信号中两个相邻通道间的相干函数,再利用通道间信号的相干性来进行初始噪声抑制。其次,通过一个频域宽带最小方差无畸变响应(Minimum Variance Distortionless Response,MVDR)波束形成器保留目标声源方向的信号并抑制其他方向的信号干扰,再通过改进的维纳滤波器去除噪声残留提升语音质量。最后,使用梅尔频率倒谱系数(Mel Frequency Cepstral Coefficients,MFCC)和伽马通滤波器组频率倒谱系数(Gammatone Filter-bank Frequency Cepstral Coefficients,GFCC)对增强后的语音信号做特征参数提取并进行说话人识别。仿真过程采用声学人工头模拟双耳采集数据,实验结果表明,该语音增强算法在复杂噪声环境下能够获得较好的增强效果,能有效提升说话人识别系统的识别率。 相似文献
17.
模式识别在生物医学工程中的应用 总被引:1,自引:0,他引:1
模式识别是一门研究对象描述和分类方法的学科,近年来将模式识别方法应用到生物医学上,成为生物医学工程内的一个热门话题。本文详细介绍了模式识别的基本方法及其在生物医学图像和生物信息学中的应用情况,阐述了它在生物医学工程中应用的实际意义,分析了它作为一交叉学科的发展前景。 相似文献
18.
At present, the methods of analyzing the stability of slope under earthquake are not accurate and reasonable because of some limitations. Based on the real dynamic tensile-shear failure mechanism of slope, the paper proposes dynamic analysis of strength reduction FEM and takes the reduction of shear strength parameters and tensile strength parameters into consideration. And it comprehensively takes the transfixion of the failure surface, the non-convergence of calculation and mutation of displacement as the criterion of dynamic instability and failure of the slope. The strength reduction factor under limit state is regarded as the dynamic safety factor of the slope under earthquake effect and its advantages are introduced. Finally, the method is applied in the seismic design of anchors supporting and anti-slide pile supporting of the slope. Calculation examples show that the application of dynamic analysis of strength reduction is feasible in the seismic design of slope engineering, which can consider dynamic interaction of supporting structure and rock-soil mass. Owing to its preciseness and great advantages, it is a new method in the seismic design of slope supporting. 相似文献
19.
With an increase in complex designs and tighter tolerances, the Coordinate Measuring Machine inspection process has become increasingly more advanced. By inspection planning, design data can be transferred to an inspection system and an entire inspection operation can be carried out with a minimum of time and with reduced uncertainty. The current need is to automate this process completely so that the inspection plan can be generated directly from the design information. Two modules of inspection planning, i.e. selection of part orientation and probe orientation sequencing, have not been dealt with properly. Also, some important factors for the selection of part orientation have been neglected and proper weights have not been given to the probe-orientation sequencing criteria. An attempt was made to overcome these limitations. Both problems have been approached as the ranking of a number of alternatives based on multiple criteria, where each criterion has unequal importance. To get the optimum probe-orientation sequence and stable part orientation, fuzzy logic was applied. Fuzzy sets were obtained and combined using a suitable methodology. To explain and validate the proposed methodology, an example part was taken. As a practical case, an engine block was considered and the results presented. 相似文献