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An Effective SVM Ensemble Algorithm Based on Different Thresholds of PCA
Yukai Yao,Bo Wang,Qingjun Yang,Dongsheng Ji,Tao Ma,Xiaoyun Chen 보안공학연구지원센터 2016 International Journal of Database Theory and Appli Vol.9 No.2
This paper proposes an effective ensemble classifier, named PCAenSVM, which consists of ten weak Support Vector Machine classifiers based on different Principal Component Analysis thresholds. Those ten base Support Vector Machine classifiers are made up to fulfill classification tasks using Majority Voting strategy. Experiments are made on four UCI data sets and a data set from the Uppsala University to evaluate the performances of PCAenSVM. The results of PCAenSVM are compared with that of LibSVM and EnsembleSVM. Experimental results show that PCAenSVM has better classification accuracy than other two algorithms. Moreover, PCAenSVM has the same confidence level with the LibSVM, and its confidences of accuracy and sensitivity on those five data sets outperform that of the EnsembleSVM.
Kuijing Song,Xinquan Liu,Yukai Ji,Yong Wei,Junrui Luo,Fei Liu,Dashuang Liu,Zhihong Zhong 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.4
Aluminum/magnesium (Al/Mg) alloys have good metallurgical compatibility as well as similar melting and recrystallizationtemperatures. Therefore, the formation of deleterious IMCs is considered as a major problem in dissimilar Al/Mgalloys joining. In this paper, the metallurgical reaction behavior and atomic diffusion in Al/Mg solid state joining interfaceare studied. Based on the thermodynamic, kinetic and crystallographic characteristics of ordered phase transformation andatomic diffusion database, a phase field calculation framework of the polycrystalline β–Al3Mg2 and γ–Al12Mg17 evolutionis developed. Diffusivity, D and interface mobility, M, which significant kinetic parameters are defined as alloy compositionsand joining conditions dependent. By a series of simulation, it is proved the simulated interdiffusion microstructuralcharacteristics and element distribution across the joining interface are in coincidence with the corresponding experimentaldata. The thermally activated IMC evolution in diffusion bonding is in thermodynamic equilibrium, while accelerated IMCevolution in friction stir welding results from thermomechanically activated D and M. The present study contributes to theunderstanding of interfacial microstructures evolution in solid state joining of dissimilar alloys.