This work is partially supported by National Natural Science Foundation of China (12401356), National Statistical Science Research Project of China (2022LY089), the Natural Science Foundation of Shanxi normal University (JYCJ2022004),the 2025 Planning Research Topics of Commerce Statistical Society of China (2025STY119) and Postgraduate Education Innovation Program of Shanxi Province (2025XS110).
12401356,2022LY089,JYCJ2022004,2025XS110.
The functional quadratic regression model assumes a polynomial, rather than linear relationship between the scalar response variable and a functional predictor variable. This paper focuses on the statistical inference tailored for the functional quadratic expectile regression model. Functional coefficients are approximated by the functional principal component basis functions, and asymptotic properties of estimators are derived under some mild conditions. Furthermore, to inspect the effect of the functional quadratic term on the response variable, we develop an expectile rank score test and establish its asymptotic property. Simulations are conducted to assess the empirical performance of the proposed estimation methods and test statistic. Results indicate that the proposed estimators are comparable to competing estimation methods and the newly proposed expectile rank score test is effective. Finally, the advantages of our methodologies are illustrated using a real-data example.
expectile regression expectile rank score test functional quadratic regression model functional principal component analysis
This manuscript is original work not previously published and is not being considered elsewhere.
Shanxi Normal University
12401356,2022LY089,JYCJ2022004,2025XS110.
This work is partially supported by National Natural Science Foundation of China (12401356), National Statistical Science Research Project of China (2022LY089), the Natural Science Foundation of Shanxi normal University (JYCJ2022004) and Postgraduate Education Innovation Program of Shanxi Province (2025XS110).
| Primary Language | English |
|---|---|
| Subjects | Large and Complex Data Theory, Statistical Theory |
| Journal Section | Research Article |
| Authors | |
| Project Number | 12401356,2022LY089,JYCJ2022004,2025XS110. |
| Submission Date | November 16, 2025 |
| Acceptance Date | January 28, 2026 |
| Early Pub Date | February 12, 2026 |
| Publication Date | February 12, 2026 |
| DOI | https://doi.org/10.15672/hujms.1824224 |
| IZ | https://izlik.org/JA38KT67PL |
| Published in Issue | Year 2026 Issue: Advanced Online Publication |
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