arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2103.08218math.NAcs.NA
收藏

(Tikhonov)正则化的一种新解释

A new interpretation of (Tikhonov) regularization

Daniel Gerth

摘要:

线性前向算子的带平方范数罚的Tikhonov正则化在文献中得到了广泛的研究。然而,收敛理论的结果是基于技术证明和难以解释。通常也不清楚这些结果如何转化为离散的数字设置。在本文中,我们提出了一种新的策略来研究正则化方法的性质的例子Tikhonov正则化。该技术是基于Tikhonov正则化的观察,逼近未知的精确解的范围内的伴随的向前运营商。这与近似源条件的概念密切相关,我们将其概括为不仅描述未知解的近似,而且描述无噪声和噪声数据;所有这些都来自同一源空间。结合这三个近似结果,我们得到了众所周知的收敛结果,在一个简洁的方式,并提高理解,通过收紧之间的关系,如收敛速度,参数选择和饱和度的概念。新的技术不仅限于Tikhonov正则化,它也可以应用于迭代正则化,我们证明了有关Tikhonov正则化和Landweber迭代。由于吉洪诺夫泛函不再是分析的核心,我们可以证明吉洪诺夫正则化可以用于过平滑正则化。所有结果都附有数值例子。

英文摘要:

Tikhonov regularization with square-norm penalty for linear forward operators has been studied extensively in the literature. However, the results on convergence theory are based on technical proofs and difficult to interpret. It is also often not clear how those results translate into the discrete, numerical setting. In this paper we present a new strategy to study the properties of a regularization method on the example of Tikhonov regularization. The technique is based on the observation that Tikhonov regularization approximates the unknown exact solution in the range of the adjoint of the forward operator. This is closely related to the concept of approximate source conditions, which we generalize to describe not only the approximation of the unknown solution, but also noise-free and noisy data; all from the same source space. Combining these three approximation results we derive the well-known convergence results in a concise way and improve the understanding by tightening the relation between concepts such as convergence rates, parameter choice, and saturation. The new technique is not limited to Tikhonov regularization, it can be applied also to iterative regularization, which we demonstrate by relating Tikhonov regularization and Landweber iteration. Because the Tikhonov functional is no longer the centrepiece of the analysis, we can show that Tikhonov regularization can be used for oversmoothing regularization. All results are accompanied by numerical examples.

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。

↑