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arXiv 2302.11222stat.ME
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似相似源非参数回归的源函数加权迁移学习

Source-Function Weighted-Transfer Learning for Nonparametric Regression with Seemingly Similar Sources

Lu Lin, Weiyu Li

摘要:

同质性,或者更一般地说,源域和目标域之间的相似性似乎对正迁移学习至关重要。然而,在实践中,相似性条件很难检查,并且经常被违反。本文引入了一种由非正交性和光滑性定义的似相似性来代替常用的相似性条件。这一条件在一般情况下自然满足,甚至隐含着某种意义上的相异。基于表面相似性和$L_2$ -调整,源函数加权转移学习估计(sw-TLE)的构造。通过源函数加权,实现了自适应迁移学习,在某种意义上说,它适用于类似和不类似的情况下,具有相对较高的估计效率。特别地,在同质源和目标模型的情况下,sw-TLE甚至可以与全数据估计器竞争。建立了源函数加权估计量与James-Stein估计量之间的隐含关系,揭示了该方法的结构合理性。此外,该策略确实适用于非参数和半参数模型。综合仿真研究和实际数据分析表明,新策略明显优于竞争对手。

英文摘要:

The homogeneity, or more generally, the similarity between source domains and a target domain seems to be essential to a positive transfer learning. In practice, however, the similarity condition is difficult to check and is often violated. In this paper, instead of the popularly used similarity condition, a seeming similarity is introduced, which is defined by a non-orthogonality together with a smoothness. Such a condition is naturally satisfied under common situations and even implies the dissimilarity in some sense. Based on the seeming similarity together with an $L_2$-adjustment, a source-function weighted-transfer learning estimation (sw-TLE) is constructed. By source-function weighting, an adaptive transfer learning is achieved in the sense that it is applied to similar and dissimilar scenarios with a relatively high estimation efficiency. Particularly, under the case with homogenous source and target models, the sw-TLE even can be competitive with the full data estimator. The hidden relationship between the source-function weighting estimator and the James-Stein estimator is established as well, which reveals the structural reasonability of our methodology. Moreover, the strategy does apply to nonparametric and semiparametric models. The comprehensive simulation studies and real data analysis can illustrate that the new strategy is significantly better than the competitors.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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