神经科学家和机器学习研究人员通常引用对抗的例子,作为计算模型如何从生物感官系统发散的示例。最近的工作已经提出将生物启发组件添加到视觉神经网络中,作为提高其对抗性鲁棒性的一种方式。一种令人惊讶的有效组分,用于减少对抗性脆弱性是响应随机性,例如由生物神经元呈现的响应性随机性。在这里,使用最近开发的从计算神经科学的几何技术,我们研究了对抗性扰动如何影响标准,前列培训和生物学启发的随机网络的内部表示。我们为每种类型的网络找到了不同的几何签名,揭示了实现稳健表示的不同机制。接下来,我们将这些结果概括为听觉域,表明神经插值性也使听觉模型对对抗对抗扰动更鲁棒。随机网络的几何分析揭示了清洁和离前动脉扰动刺激的表示之间的重叠,并且定量表现出随机性的竞争几何效果在对抗和清洁性能之间调解权衡。我们的结果阐明了通过对外内培训和随机网络利用的强大感知的策略,并帮助解释了随机性如何有利于机器和生物计算。
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How do we know when the predictions made by a classifier can be trusted? This is a fundamental problem that also has immense practical applicability, especially in safety-critical areas such as medicine and autonomous driving. The de facto approach of using the classifier's softmax outputs as a proxy for trustworthiness suffers from the over-confidence issue; while the most recent works incur problems such as additional retraining cost and accuracy versus trustworthiness trade-off. In this work, we argue that the trustworthiness of a classifier's prediction for a sample is highly associated with two factors: the sample's neighborhood information and the classifier's output. To combine the best of both worlds, we design a model-agnostic post-hoc approach NeighborAgg to leverage the two essential information via an adaptive neighborhood aggregation. Theoretically, we show that NeighborAgg is a generalized version of a one-hop graph convolutional network, inheriting the powerful modeling ability to capture the varying similarity between samples within each class. We also extend our approach to the closely related task of mislabel detection and provide a theoretical coverage guarantee to bound the false negative. Empirically, extensive experiments on image and tabular benchmarks verify our theory and suggest that NeighborAgg outperforms other methods, achieving state-of-the-art trustworthiness performance.
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