## Journal of Central South University

 第50卷    第7期    总第299期    2019年7月

[PDF全文下载]    [Flash在线阅读]

(1. 山东科技大学 资源与土木工程系，山东 泰安，271019；
2. 山东建筑大学 测绘地理信息学院，山东 济南，250101；
3. 中煤科工集团 重庆研究院有限公司，重庆，400039；
4. 山东农业大学 水利土木工程学院，山东 泰安，271018
)

Determination of regularization parameter in semiparametric model based on U curve method

1. Department of Resources and Civil Engineering, Shandong University of Science and Technology, Tai’an 271019, China；
2. College of Surveying and Geo-Informatics, Shandong Jianzhu University, Jinan 250101, China；
3. CCTEG Chongqing Research Institute, Chongqing 400039, China；
4. School of Water Conservancy and Civil Engineering, Shandong Agricultural University, Tai''an 271018, China

Abstract:To solve the problem of the regularization parameter in the semiparametric model, the U curve method was researched as a regularization parameter selection method. By determining the appropriate regularization parameters, the balance between the residual part and the smoothness part was better controlled, and more accurate parameter estimation was obtained. Through the simulation examples and real examples, the parametric estimation solution of the semiparametric model based on the U curve method to determine the regularization parameters was compared with other methods. The results show that when the simulated system error is periodic, the parameter estimation is obtained by using the regularized parameters determined by U-curve method and L-curve method respectively, and the norm of the difference vector between it and its true value is respectively 4.632 4×10-4 and 3.497 0×10-4. When the simulated system error is linear periodicity, the parameter estimation is also obtained by using the regularized parameters determined by U-curve method and L-curve method respectively，and the norm of the difference vector between it and its true value is respectively 7×10-4 and 4×10-4. By comparison, the accuracy of parameter estimation by using the regularized parameters determined by U-curve method is better than that by L-curve method, and the U-curve method can better separate the systematic errors from the observed values.

Key words: semiparametric model; regularization parameter; L curve method; U curve method

 中南大学学报（自然科学版） ISSN 1672-7207 CN 43-1426/NZDXZAC 中南大学学报（英文版） ISSN 2095-2899 CN 43-1516/TBJCSTFT