提出了一种新的高光谱图像波段选择方法——波段最大筛选法(Maximum Band Screening,MBS),它将每个波段的像元光谱分量看成一条波段向量,利用光谱相似性度量比较波段与已选波段的不相似性,从而从原始波段中选择信息量既大、又有区别性...提出了一种新的高光谱图像波段选择方法——波段最大筛选法(Maximum Band Screening,MBS),它将每个波段的像元光谱分量看成一条波段向量,利用光谱相似性度量比较波段与已选波段的不相似性,从而从原始波段中选择信息量既大、又有区别性的波段。为了验证MBS的有效性,将其用于高光谱图像异常探测,设计了异常探测算法。该算法首先从高光谱图像中提取异常目标光谱,噪声白化后,进行MBS波段选择,最后将选出的波段用于自适应余弦估计(Adaptive Coherence Estimator,ACE)目标探测。采用AVIRIS高光谱图像将MBS与另外两种波段选择算法进行比较分析,实验结果表明,在MBS选出的仅占全部波段8%的波段上,ACE算子具有较高的探测性能。展开更多
This paper develops a wheel profile fine-tuning system(WPFTS)that comprehensively considers the influence of wheel profile on wheel damage,vehicle stability,vehicle safety,and passenger comfort.WPFTS can recommend one...This paper develops a wheel profile fine-tuning system(WPFTS)that comprehensively considers the influence of wheel profile on wheel damage,vehicle stability,vehicle safety,and passenger comfort.WPFTS can recommend one or more optimized wheel profiles according to train operators’needs,e.g.,reducing wheel wear,mitigating the development of wheel out-of-roundness(OOR),improving the shape stability of the wheel profile.Specifically,WPFTS includes four modules:(I)a wheel profile generation module based on the rotary-scaling finetuning(RSFT)method;(II)a multi-objective generation module consisting of a rigid multi-body dynamics simulation(MBS)model,an analytical model,and a rigid–flexible MBS model,for generating 11 objectives related to wheel damage,vehicle stability,vehicle safety,and passenger comfort;(III)a weight assignment module consisting of an adaptive weight assignment strategy and a manual weight assignment strategy;and(IV)an optimization module based on radial basis function(RBF)and particle swarm optimization(PSO).Finally,three cases are introduced to show how WPTFS recommends a wheel profile according to train operators’needs.Among them,a wheel profile with high shape stability,a wheel profile for mitigating the development of wheel OOR,and a wheel profile considering hunting stability and derailment safety are developed,respectively.展开更多
Based on the theory of multi-body system (MBS), bine’s and huston’s methods are applied to an on-line measuring system of machining center in this paper. Through the study on modeling technique, the comprehensive mo...Based on the theory of multi-body system (MBS), bine’s and huston’s methods are applied to an on-line measuring system of machining center in this paper. Through the study on modeling technique, the comprehensive model for errors calculation in an on-line measuring System of machining center have been built for the first time. Using this model, the errors can be compensated by soft.ware and the measuring accuracy can be enhanced without any more inveSt. This model can be used in all kinds of machining center.展开更多
文摘提出了一种新的高光谱图像波段选择方法——波段最大筛选法(Maximum Band Screening,MBS),它将每个波段的像元光谱分量看成一条波段向量,利用光谱相似性度量比较波段与已选波段的不相似性,从而从原始波段中选择信息量既大、又有区别性的波段。为了验证MBS的有效性,将其用于高光谱图像异常探测,设计了异常探测算法。该算法首先从高光谱图像中提取异常目标光谱,噪声白化后,进行MBS波段选择,最后将选出的波段用于自适应余弦估计(Adaptive Coherence Estimator,ACE)目标探测。采用AVIRIS高光谱图像将MBS与另外两种波段选择算法进行比较分析,实验结果表明,在MBS选出的仅占全部波段8%的波段上,ACE算子具有较高的探测性能。
基金This work was supported by China Scholarship Council(Grant No.201707000113).
文摘This paper develops a wheel profile fine-tuning system(WPFTS)that comprehensively considers the influence of wheel profile on wheel damage,vehicle stability,vehicle safety,and passenger comfort.WPFTS can recommend one or more optimized wheel profiles according to train operators’needs,e.g.,reducing wheel wear,mitigating the development of wheel out-of-roundness(OOR),improving the shape stability of the wheel profile.Specifically,WPFTS includes four modules:(I)a wheel profile generation module based on the rotary-scaling finetuning(RSFT)method;(II)a multi-objective generation module consisting of a rigid multi-body dynamics simulation(MBS)model,an analytical model,and a rigid–flexible MBS model,for generating 11 objectives related to wheel damage,vehicle stability,vehicle safety,and passenger comfort;(III)a weight assignment module consisting of an adaptive weight assignment strategy and a manual weight assignment strategy;and(IV)an optimization module based on radial basis function(RBF)and particle swarm optimization(PSO).Finally,three cases are introduced to show how WPTFS recommends a wheel profile according to train operators’needs.Among them,a wheel profile with high shape stability,a wheel profile for mitigating the development of wheel OOR,and a wheel profile considering hunting stability and derailment safety are developed,respectively.
文摘Based on the theory of multi-body system (MBS), bine’s and huston’s methods are applied to an on-line measuring system of machining center in this paper. Through the study on modeling technique, the comprehensive model for errors calculation in an on-line measuring System of machining center have been built for the first time. Using this model, the errors can be compensated by soft.ware and the measuring accuracy can be enhanced without any more inveSt. This model can be used in all kinds of machining center.
