Intra-Class Mixup for Out-of-Distribution Detection

Deep neural networks (DNNs) have found widespread adoption in solving image recognition and natural language processing tasks. However, they make confident mispredictions when presented with data that does not belong to the training distribution, i.e. out-of-distribution (OoD) samples. Research has...

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Main Authors: Deepak Ravikumar, Sangamesh Kodge, Isha Garg, Kaushik Roy
Format: Article
Language:English
Published: IEEE 2023-01-01
Series:IEEE Access
Subjects:
Online Access:https://ieeexplore.ieee.org/document/10064300/
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author Deepak Ravikumar
Sangamesh Kodge
Isha Garg
Kaushik Roy
author_facet Deepak Ravikumar
Sangamesh Kodge
Isha Garg
Kaushik Roy
author_sort Deepak Ravikumar
collection DOAJ
description Deep neural networks (DNNs) have found widespread adoption in solving image recognition and natural language processing tasks. However, they make confident mispredictions when presented with data that does not belong to the training distribution, i.e. out-of-distribution (OoD) samples. Research has shown that angular representations can be useful to address the curse of dimensionality and improve OoD detection performance. However, when evaluating the angular separability using Fisher’s criterion we find that empirical risk minimization and inter-class mixup trained DNNs have low angular separability between in-distribution data and OoD data. To improve angular separability, we propose intra-class mixup. We provide mathematical reasoning that shows that intra-class mixup results in reduced angular spread because of reduced variance at the input during training. Further, to take full advantage of improved angular separability from intra-class mixup we propose supplementing the separation metric with the cosine of angular margin to improve OoD detection. Angular margin is the angle between the final layer weight vector and the sample representation. The proposed intra-class mixup when applied to various existing OoD detection techniques shows an improvement of 4.21% and 6.21% in AUROC performance over empirical risk minimization and inter-class mixup, respectively. Further, intra-class mixup aided with the cosine of angular margin improves AUROC performance by 6.71% and 8.75% over empirical risk minimization and inter-class mixup, respectively.
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spelling doaj.art-286cd5c4316f4bcf8f72a6fad313fe742023-03-20T23:00:14ZengIEEEIEEE Access2169-35362023-01-0111259682598110.1109/ACCESS.2023.325492010064300Intra-Class Mixup for Out-of-Distribution DetectionDeepak Ravikumar0https://orcid.org/0000-0001-6736-3250Sangamesh Kodge1https://orcid.org/0000-0001-9713-5400Isha Garg2https://orcid.org/0000-0003-4702-9444Kaushik Roy3https://orcid.org/0000-0002-0735-9695School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, USASchool of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, USASchool of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, USASchool of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, USADeep neural networks (DNNs) have found widespread adoption in solving image recognition and natural language processing tasks. However, they make confident mispredictions when presented with data that does not belong to the training distribution, i.e. out-of-distribution (OoD) samples. Research has shown that angular representations can be useful to address the curse of dimensionality and improve OoD detection performance. However, when evaluating the angular separability using Fisher’s criterion we find that empirical risk minimization and inter-class mixup trained DNNs have low angular separability between in-distribution data and OoD data. To improve angular separability, we propose intra-class mixup. We provide mathematical reasoning that shows that intra-class mixup results in reduced angular spread because of reduced variance at the input during training. Further, to take full advantage of improved angular separability from intra-class mixup we propose supplementing the separation metric with the cosine of angular margin to improve OoD detection. Angular margin is the angle between the final layer weight vector and the sample representation. The proposed intra-class mixup when applied to various existing OoD detection techniques shows an improvement of 4.21% and 6.21% in AUROC performance over empirical risk minimization and inter-class mixup, respectively. Further, intra-class mixup aided with the cosine of angular margin improves AUROC performance by 6.71% and 8.75% over empirical risk minimization and inter-class mixup, respectively.https://ieeexplore.ieee.org/document/10064300/Deep learningdeep neural netsmixupintra-class mixupout-of-distribution detectionangular margin
spellingShingle Deepak Ravikumar
Sangamesh Kodge
Isha Garg
Kaushik Roy
Intra-Class Mixup for Out-of-Distribution Detection
IEEE Access
Deep learning
deep neural nets
mixup
intra-class mixup
out-of-distribution detection
angular margin
title Intra-Class Mixup for Out-of-Distribution Detection
title_full Intra-Class Mixup for Out-of-Distribution Detection
title_fullStr Intra-Class Mixup for Out-of-Distribution Detection
title_full_unstemmed Intra-Class Mixup for Out-of-Distribution Detection
title_short Intra-Class Mixup for Out-of-Distribution Detection
title_sort intra class mixup for out of distribution detection
topic Deep learning
deep neural nets
mixup
intra-class mixup
out-of-distribution detection
angular margin
url https://ieeexplore.ieee.org/document/10064300/
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