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arXiv 2106.09385cs.LGcs.CV
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关于通过正则化进行深度神经网络校准及其对细化的影响

On Deep Neural Network Calibration by Regularization and its Impact on Refinement

Aditya Singh, Alessandro Bay, Biswa Sengupta, Andrea Mirabile

摘要:

深度神经网络已经被证明是高度错误的。他们往往对自己的预测过于自信。它对安全关键系统提出了一个重大挑战,即可靠地利用深度神经网络(DNN)。许多最近提出的缓解这种情况的方法已经证明在改进DNN校准方面取得了实质性进展。然而,他们几乎没有触及细化,这在历史上一直是校准的一个重要方面。细化表示网络正确和不正确预测的可分性。本文提出了一个理论和实证支持的论述,审查校准模型的完善。首先,我们将预期校准误差(ECE)分解为预测置信度和过度自信预测假设下的细化。其次,与此结果相联系,我们强调基于正则化的校准只关注于天真地降低模型的置信度。从逻辑上讲,这对模型的改进有严重的不利影响,因为正确和不正确的预测变得紧密耦合。最后,连接细化与ECE也提供了支持现有的细化为基础的方法,提高校准,但不解释背后的推理it. We支持我们的主张,通过严格的经验评估,许多国家的最先进的校准方法广泛使用的数据集和神经网络。我们发现,许多校准方法,如标签平滑,混合等,通过降低DNN的精度来降低其有用性。即使在自然数据偏移下,这种校准-细化权衡也适用于大多数校准方法。

英文摘要:

Deep neural networks have been shown to be highly miscalibrated. often they tend to be overconfident in their predictions. It poses a significant challenge for safety-critical systems to utilise deep neural networks (DNNs), reliably. Many recently proposed approaches to mitigate this have demonstrated substantial progress in improving DNN calibration. However, they hardly touch upon refinement, which historically has been an essential aspect of calibration. Refinement indicates separability of a network's correct and incorrect predictions. This paper presents a theoretically and empirically supported exposition reviewing refinement of a calibrated model. Firstly, we show the breakdown of expected calibration error (ECE), into predicted confidence and refinement under the assumption of over-confident predictions. Secondly, linking with this result, we highlight that regularization based calibration only focuses on naively reducing a model's confidence. This logically has a severe downside to a model's refinement as correct and incorrect predictions become tightly coupled. Lastly, connecting refinement with ECE also provides support to existing refinement based approaches which improve calibration but do not explain the reasoning behind it. We support our claims through rigorous empirical evaluations of many state of the art calibration approaches on widely used datasets and neural networks. We find that many calibration approaches with the likes of label smoothing, mixup etc. lower the usefulness of a DNN by degrading its refinement. Even under natural data shift, this calibration-refinement trade-off holds for the majority of calibration methods.

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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