The resonance demodulation technique has been widely employed in vibration signal analysis. In order to construct a proper bandpass filter, the prior knowledge, i.e. the resonance frequency band of the mechanical syst...
详细信息
The resonance demodulation technique has been widely employed in vibration signal analysis. In order to construct a proper bandpass filter, the prior knowledge, i.e. the resonance frequency band of the mechanical system is required in the traditional demodulation method. However, as the collected vibration signal is often tainted by the background noise and interferences often with unknown frequency contents, it is difficult to identify the center frequency and the bandwidth of the filter. This paper introduces a clustering-based segmentation method to determine these parameters automatically. Envelope analysis is then applied to demodulating the vibration data. According to the simulated cases, the proposed approach is robust to Gaussian noise and interferences. Its effectiveness is further validated by applying it to detect rolling bearing faults based on experimental data.
In this study, we described the effects of image smoothing on image segmentation, introduced a method proposed by Yang et al. for removing smoothing effects (hereafter referred as Yang's method), and modified this...
详细信息
ISBN:
(纸本)9781479986965
In this study, we described the effects of image smoothing on image segmentation, introduced a method proposed by Yang et al. for removing smoothing effects (hereafter referred as Yang's method), and modified this method to solve image segmentation problems. The results showed that Yang's smoothing method still required further improvements;therefore, two solutions to solving problems related to this method were proposed. In Yang's method, the researchers only considered removing the effects of central pixels in a mask on mask calculation, neglecting the effects of edge pixels in a region of a mask on mask calculation. Therefore, we incorporated an edge mask calculation into Yang's method. Moreover, in Yang's method, distinct color masks are contained in the color components of a single pixel, which cause these components to yield differing adjustment results. Thus, the solution to this problem is to adopt a single-colored mask for color adjustments. The experimental results verified that the method proposed in this study effectively improved Yang's method and removed the effects of smoothing on image segmentation.
This paper presents a new clustering-based algorithm for noisy image segmentation. Fuzzy C-Means (FCM), empowered with a new similarity metric, acts as the clustering method. The common Euclidean distance metric in FC...
详细信息
ISBN:
(纸本)9783319282701;9783319282695
This paper presents a new clustering-based algorithm for noisy image segmentation. Fuzzy C-Means (FCM), empowered with a new similarity metric, acts as the clustering method. The common Euclidean distance metric in FCM has been modified with information extracted from a local neighboring window surrounding each pixel. Having different local features extracted for each pixel, Particle Swarm Optimization (PSO) is utilized to combine them in a weighting scheme while forming the proposed similarity metric. This allows each feature to contribute to the clustering performance, resulting in more accurate segmentation results in noisy images compared to other state-of-the-art methods.
Characteristics of the tire footprint are major indicators of tire performance and provide relevant information that can be used to improve the tire design process. However, the accurate segmentation of the tire footp...
详细信息
Characteristics of the tire footprint are major indicators of tire performance and provide relevant information that can be used to improve the tire design process. However, the accurate segmentation of the tire footprint requires prior training and can be a highly man-hour consuming task. In order to overcome such drawbacks, scientists have made multiple efforts to design methods for segmenting the tire footprint automatically but it is still an open problem. In this paper, we propose a novel methodology to estimate the tire footprint under dynamic conditions and conduct an extensive subjective assessment of its quality. For this aim, we designed a subjective evaluation procedure based on the ITU-R BT. 500-13 recommendation. In addition, we include a quantitative comparison of several tire contact patch segmentation methods using ray feature error and Dice index. The results of our methodology have been evaluated by expert tire engineers and will allow us to improve the tire manufacturing process.
Automated image detection of white matter changes of the brain is essentially helpful in providing a quantitative measure for studying the association of white matter lesions with other types of biomedical data. Such ...
详细信息
ISBN:
(纸本)9781424441242
Automated image detection of white matter changes of the brain is essentially helpful in providing a quantitative measure for studying the association of white matter lesions with other types of biomedical data. Such study allows the possibility of several medical hypothesis validations which lead to therapeutic treatment and prevention. This paper presents a new clustering-based segmentation approach for detecting white matter changes in magnetic resonance imaging with particular reference to cognitive decline in the elderly. The proposed method is formulated using the principles of fuzzy.. means algorithm and geostatistics.
The presence of periodical impulses in vibration signals usually indicates the occurrence of faults in roller bearings. Unfortunately, in the complex working condition with the heavy noises, fault detection in mechani...
详细信息
ISBN:
(纸本)9781538653807
The presence of periodical impulses in vibration signals usually indicates the occurrence of faults in roller bearings. Unfortunately, in the complex working condition with the heavy noises, fault detection in mechanical systems is often difficult. To solve this problem, a hybrid method of ensemble empirical mode decomposition (EEMD) and L-Kurtosis clustering-based segmentation is proposed. EEMD is similar to empirical mode decomposition (EMD), which can express the intrinsic essence using simple and understandable algorithm to solve the mode mixing phenomenon. L-Kurtosis is the improved version of kurtosis to recognize the impulses without the influence of outliers. Furthermore, the L-Kurtosis value is employed as an indicator in the clustering-based segmentation method to extract the fault features from the background noises. To illustrate the feasibility of utilizing the EEMD and L-Kurtosis basedclusteringsegmentation method, benchmark data simulations and experimental investigations are performed to detect faults in bearings. The results show that the proposed method enables the efficient recognition of faults in bearings.
暂无评论