282 research outputs found
Constraining the Higgs sector from False Vacua in the Next-to-Minimal Supersymmetric Standard Model
We study the mass, the mixing and the coupling with boson of the lightest
Higgs boson in the next-to-minimal supersymmetric standard model. The vacuum
structure of the Higgs potential is analyzed and the new false vacua are
discussed. The significant parameter region can be excluded by requiring that
the realistic vacuum is deeper than false vacua, which result in constraints on
the properties of the lightest Higgs boson.Comment: 23 pages, 8 figure
Understanding Likelihood of Normalizing Flow and Image Complexity through the Lens of Out-of-Distribution Detection
Out-of-distribution (OOD) detection is crucial to safety-critical machine
learning applications and has been extensively studied. While recent studies
have predominantly focused on classifier-based methods, research on deep
generative model (DGM)-based methods have lagged relatively. This disparity may
be attributed to a perplexing phenomenon: DGMs often assign higher likelihoods
to unknown OOD inputs than to their known training data. This paper focuses on
explaining the underlying mechanism of this phenomenon. We propose a hypothesis
that less complex images concentrate in high-density regions in the latent
space, resulting in a higher likelihood assignment in the Normalizing Flow
(NF). We experimentally demonstrate its validity for five NF architectures,
concluding that their likelihood is untrustworthy. Additionally, we show that
this problem can be alleviated by treating image complexity as an independent
variable. Finally, we provide evidence of the potential applicability of our
hypothesis in another DGM, PixelCNN++.Comment: Accepted at AAAI-2
Out-of-Distribution Detection with Reconstruction Error and Typicality-based Penalty
The task of out-of-distribution (OOD) detection is vital to realize safe and
reliable operation for real-world applications. After the failure of
likelihood-based detection in high dimensions had been shown, approaches based
on the \emph{typical set} have been attracting attention; however, they still
have not achieved satisfactory performance. Beginning by presenting the failure
case of the typicality-based approach, we propose a new reconstruction
error-based approach that employs normalizing flow (NF). We further introduce a
typicality-based penalty, and by incorporating it into the reconstruction error
in NF, we propose a new OOD detection method, penalized reconstruction error
(PRE). Because the PRE detects test inputs that lie off the in-distribution
manifold, it effectively detects adversarial examples as well as OOD examples.
We show the effectiveness of our method through the evaluation using natural
image datasets, CIFAR-10, TinyImageNet, and ILSVRC2012.Comment: Accepted at WACV 202
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