87,741 research outputs found
Masking: A New Perspective of Noisy Supervision
It is important to learn various types of classifiers given training data
with noisy labels. Noisy labels, in the most popular noise model hitherto, are
corrupted from ground-truth labels by an unknown noise transition matrix. Thus,
by estimating this matrix, classifiers can escape from overfitting those noisy
labels. However, such estimation is practically difficult, due to either the
indirect nature of two-step approaches, or not big enough data to afford
end-to-end approaches. In this paper, we propose a human-assisted approach
called Masking that conveys human cognition of invalid class transitions and
naturally speculates the structure of the noise transition matrix. To this end,
we derive a structure-aware probabilistic model incorporating a structure
prior, and solve the challenges from structure extraction and structure
alignment. Thanks to Masking, we only estimate unmasked noise transition
probabilities and the burden of estimation is tremendously reduced. We conduct
extensive experiments on CIFAR-10 and CIFAR-100 with three noise structures as
well as the industrial-level Clothing1M with agnostic noise structure, and the
results show that Masking can improve the robustness of classifiers
significantly.Comment: NIPS 2018 camera-ready versio
The detection of influential subsets in linear regression using an influence matrix.
This paper presents a new method to identify influential subsets in linear regression problems. The procedure uses the eigenstructure of an influence matrix which is defined as the matrix of uncentered covariance of the effect on the whole data set of deleting each observation, normalized to include the univariate Cook's statistics in the diagonal. It is shown that points in an influential subset will appear with large weight in at least one of the eigenvector linked to the largest eigenvalues in this influence matrix. The method is illustrated with several well-known examples in the literature, and in all of them it succeeds in identifying the relevant influential subsets.Eigenvectors; Masking; Multivariate Influence; Outliers;
Single channel speech music separation using nonnegative matrix factorization and spectral masks
A single channel speech-music separation algorithm based on nonnegative matrix factorization (NMF) with spectral masks is proposed in this work. The proposed algorithm uses training data of speech and music signals with nonnegative matrix factorization followed by masking to separate the mixed signal. In the training stage, NMF uses the training data to train a set of basis vectors for each source. These bases are trained using NMF in the magnitude spectrum domain. After observing the mixed signal, NMF is used to decompose its magnitude spectra into a linear combination of the trained bases for both sources. The decomposition results are used to build a mask, which explains the contribution of each source in the mixed signal. Experimental results show that using masks after NMF improves the separation process even when calculating NMF with fewer iterations, which yields a faster separation process
Taste masked thin films printed by jet dispensing
Taste masking of bitter active substances is an emerging area in the pharmaceutical industry especially for paediatric/geriatric medications. In this study we introduce the use of jet – dispensing as a taste masking technology by printing mucosal thin films of three model bitter substances, Cetirizine HCl, Diphenylhydramine HCl and Ibuprofen. The process was used to dispense aqueous drugs/polymer solutions at very high speed where eventually the drugs were embedded in the polymer matrix. The in vivo evaluation of jet – dispensed mucosal films showed excellent taste masking for drug loadings from 20 - 40%. Jet dispensing was proved to make uniform, accurate and reproducible thin films with excellent content uniformity
On the Duality of Probing and Fault Attacks
In this work we investigate the problem of simultaneous privacy and integrity
protection in cryptographic circuits. We consider a white-box scenario with a
powerful, yet limited attacker. A concise metric for the level of probing and
fault security is introduced, which is directly related to the capabilities of
a realistic attacker. In order to investigate the interrelation of probing and
fault security we introduce a common mathematical framework based on the
formalism of information and coding theory. The framework unifies the known
linear masking schemes. We proof a central theorem about the properties of
linear codes which leads to optimal secret sharing schemes. These schemes
provide the lower bound for the number of masks needed to counteract an
attacker with a given strength. The new formalism reveals an intriguing duality
principle between the problems of probing and fault security, and provides a
unified view on privacy and integrity protection using error detecting codes.
Finally, we introduce a new class of linear tamper-resistant codes. These are
eligible to preserve security against an attacker mounting simultaneous probing
and fault attacks
Masking Strategies for Image Manifolds
We consider the problem of selecting an optimal mask for an image manifold,
i.e., choosing a subset of the pixels of the image that preserves the
manifold's geometric structure present in the original data. Such masking
implements a form of compressive sensing through emerging imaging sensor
platforms for which the power expense grows with the number of pixels acquired.
Our goal is for the manifold learned from masked images to resemble its full
image counterpart as closely as possible. More precisely, we show that one can
indeed accurately learn an image manifold without having to consider a large
majority of the image pixels. In doing so, we consider two masking methods that
preserve the local and global geometric structure of the manifold,
respectively. In each case, the process of finding the optimal masking pattern
can be cast as a binary integer program, which is computationally expensive but
can be approximated by a fast greedy algorithm. Numerical experiments show that
the relevant manifold structure is preserved through the data-dependent masking
process, even for modest mask sizes
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