针对以往基于离散度函数(function of degree of disagreement, FDOD)度量对航空发动机的健康状况进行综合评价时,未全面考虑各指标的权重,导致评价结果不够准确的问题,提出一种改进FDOD度量的综合评价方法。首先,利用序关系分析法(简称...针对以往基于离散度函数(function of degree of disagreement, FDOD)度量对航空发动机的健康状况进行综合评价时,未全面考虑各指标的权重,导致评价结果不够准确的问题,提出一种改进FDOD度量的综合评价方法。首先,利用序关系分析法(简称为G1法)确定各指标的主观权重,利用因子分析法确定各指标间的相关性,得到各指标的客观权重。其次,基于离差最大化的组合赋权法确定各指标的组合权重,使赋权结果更加科学合理,提高不同对象的区分度。然后,基于组合权重对传统FDOD度量进行改进,以提高综合评价的准确性。最后,通过美国国家航空航天局提供的涡扇发动机性能仿真数据,验证了所提方法的有效性。展开更多
For intelligent transportation surveillance, a novel background model based on Mart wavelet kernel and a background subtraction technique based on binary discrete wavelet transforms were introduced. The background mod...For intelligent transportation surveillance, a novel background model based on Mart wavelet kernel and a background subtraction technique based on binary discrete wavelet transforms were introduced. The background model kept a sample of intensity values for each pixel in the image and used this sample to estimate the probability density function of the pixel intensity. The density function was estimated using a new Marr wavelet kernel density estimation technique. Since this approach was quite general, the model could approximate any distribution for the pixel intensity without any assumptions about the underlying distribution shape. The background and current frame were transformed in the binary discrete wavelet domain, and background subtraction was performed in each sub-band. After obtaining the foreground, shadow was eliminated by an edge detection method. Experimental results show that the proposed method produces good results with much lower computational complexity and effectively extracts the moving objects with accuracy ratio higher than 90%, indicating that the proposed method is an effective algorithm for intelligent transportation system.展开更多
The similarity computations for fuzzy membership function pairs were carried out.Fuzzy number related knowledge was introduced,and conventional similarity was compared with distance based similarity measure.The useful...The similarity computations for fuzzy membership function pairs were carried out.Fuzzy number related knowledge was introduced,and conventional similarity was compared with distance based similarity measure.The usefulness of the proposed similarity measure was verified.The results show that the proposed similarity measure could be applied to ordinary fuzzy membership functions,though it was not easy to design.Through conventional results on the calculation of similarity for fuzzy membership pair,fuzzy membership-crisp pair and crisp-crisp pair were carried out.The proposed distance based similarity measure represented rational performance with the heuristic point of view.Furthermore,troublesome in fuzzy number based similarity measure for abnormal universe of discourse case was discussed.Finally,the similarity measure computation for various membership function pairs was discussed with other conventional results.展开更多
文摘针对以往基于离散度函数(function of degree of disagreement, FDOD)度量对航空发动机的健康状况进行综合评价时,未全面考虑各指标的权重,导致评价结果不够准确的问题,提出一种改进FDOD度量的综合评价方法。首先,利用序关系分析法(简称为G1法)确定各指标的主观权重,利用因子分析法确定各指标间的相关性,得到各指标的客观权重。其次,基于离差最大化的组合赋权法确定各指标的组合权重,使赋权结果更加科学合理,提高不同对象的区分度。然后,基于组合权重对传统FDOD度量进行改进,以提高综合评价的准确性。最后,通过美国国家航空航天局提供的涡扇发动机性能仿真数据,验证了所提方法的有效性。
基金Project(60772080) supported by the National Natural Science Foundation of ChinaProject(3240120) supported by Tianjin Subway Safety System, Honeywell Limited, China
文摘For intelligent transportation surveillance, a novel background model based on Mart wavelet kernel and a background subtraction technique based on binary discrete wavelet transforms were introduced. The background model kept a sample of intensity values for each pixel in the image and used this sample to estimate the probability density function of the pixel intensity. The density function was estimated using a new Marr wavelet kernel density estimation technique. Since this approach was quite general, the model could approximate any distribution for the pixel intensity without any assumptions about the underlying distribution shape. The background and current frame were transformed in the binary discrete wavelet domain, and background subtraction was performed in each sub-band. After obtaining the foreground, shadow was eliminated by an edge detection method. Experimental results show that the proposed method produces good results with much lower computational complexity and effectively extracts the moving objects with accuracy ratio higher than 90%, indicating that the proposed method is an effective algorithm for intelligent transportation system.
基金Project(2010-0020163) supported by Priority Research Centers Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education,Science and Technology
文摘The similarity computations for fuzzy membership function pairs were carried out.Fuzzy number related knowledge was introduced,and conventional similarity was compared with distance based similarity measure.The usefulness of the proposed similarity measure was verified.The results show that the proposed similarity measure could be applied to ordinary fuzzy membership functions,though it was not easy to design.Through conventional results on the calculation of similarity for fuzzy membership pair,fuzzy membership-crisp pair and crisp-crisp pair were carried out.The proposed distance based similarity measure represented rational performance with the heuristic point of view.Furthermore,troublesome in fuzzy number based similarity measure for abnormal universe of discourse case was discussed.Finally,the similarity measure computation for various membership function pairs was discussed with other conventional results.
