Decision trees induction algorithms have been used for classification in a wide range of application domains. In the process of constructing a tree, the criteria of selecting test attributes will influence the classif...Decision trees induction algorithms have been used for classification in a wide range of application domains. In the process of constructing a tree, the criteria of selecting test attributes will influence the classification accuracy of the tree.In this paper,the degree of dependency of decision attribute to condition attribute,based on rough set theory,is used as a heuristic for selecting the attribute that will best separate the samples into individual classes.The result of an example shows that compared with the entropy-based approach,our approach is a better way to select nodes for constructing decision trees.展开更多
Ultra-thin sheets of titanium for fabricating microchannels have been used in fuel cells due to their good corrosion resistance and high strength-weight ratio. This paper presents a constitutive model for studying the...Ultra-thin sheets of titanium for fabricating microchannels have been used in fuel cells due to their good corrosion resistance and high strength-weight ratio. This paper presents a constitutive model for studying the anisotropy effects of pure titanium(CP-Ti) sheet on the springback behavior and forming properties during the microstamping process. Thin sheets of CP-Ti specimens with different orientations were examined using uniaxial tensile tests to assess the effects of anisotropy on their mechanical properties. Then an anisotropic constitutive model considering the off-axis elastic modulus was developed based on orthotropic elasticity and Hill's yield criterion. Numerical modeling and simulation of the microstamping process for fabricating multi-channel structures were performed. The effects of anisotropy on the springback of multi-channels were investigated and compared with experimental results;the effects of tool dimension parameters on the formability of microchannel structures were also analyzed. The results showed that the anisotropy of thin titanium sheets causes various degrees of forming loads and springback in the microstamping of microchannels at different orientations. This study accurately predicts the springback of thin titanium sheet used to fabricate microchannel structures and is a good guide to the formation of such structures.展开更多
文摘Decision trees induction algorithms have been used for classification in a wide range of application domains. In the process of constructing a tree, the criteria of selecting test attributes will influence the classification accuracy of the tree.In this paper,the degree of dependency of decision attribute to condition attribute,based on rough set theory,is used as a heuristic for selecting the attribute that will best separate the samples into individual classes.The result of an example shows that compared with the entropy-based approach,our approach is a better way to select nodes for constructing decision trees.
基金supported by the National Key R&D Program of China(No.2019YFC1509503)the National Natural Science Foundation of China(No.U1809220)the Key Research and Development Program of Zhejiang Province(No.2022C01113),China.
文摘Ultra-thin sheets of titanium for fabricating microchannels have been used in fuel cells due to their good corrosion resistance and high strength-weight ratio. This paper presents a constitutive model for studying the anisotropy effects of pure titanium(CP-Ti) sheet on the springback behavior and forming properties during the microstamping process. Thin sheets of CP-Ti specimens with different orientations were examined using uniaxial tensile tests to assess the effects of anisotropy on their mechanical properties. Then an anisotropic constitutive model considering the off-axis elastic modulus was developed based on orthotropic elasticity and Hill's yield criterion. Numerical modeling and simulation of the microstamping process for fabricating multi-channel structures were performed. The effects of anisotropy on the springback of multi-channels were investigated and compared with experimental results;the effects of tool dimension parameters on the formability of microchannel structures were also analyzed. The results showed that the anisotropy of thin titanium sheets causes various degrees of forming loads and springback in the microstamping of microchannels at different orientations. This study accurately predicts the springback of thin titanium sheet used to fabricate microchannel structures and is a good guide to the formation of such structures.
