2,203 research outputs found
Cocycle deformations and Galois objects of semisimple Hopf algebras of dimension
In this article, we determine cocycle deformations and Galois objects of
non-commutative and non-cocommutative semisimple Hopf algebras of dimension
. We show that these Hopf algebras are pairwise twist inequivalent mainly
by calculating their higher Frobenius-Schur indicators, and that except three
Hopf algebras which are cocycle deformations of dual group algebras, none of
them admit non-trivial cocycle deformations.Comment: 22 page
On the realization of a class of -representations
Let be odd primes, and be irreducible representations
of and of dimensions
and , respectively. We show that if
can be realized as modular representation associated to a
modular fusion category , then . Moreover, if
contains a non-trivial \'{e}tale algebra, then
as braided fusion category, where is a near-group fusion category
of type . And we show that there exists a non-trivial
-extension of that contains simple objects of
Frobenius-Perron dimension .Comment: 20pages; comments are welcome
Adaptive Multiscale Weighted Permutation Entropy for Rolling Bearing Fault Diagnosis
Β© 2020 The Author(s). This work is licensed under a Creative Commons Attribution 4.0 License. For more information, see https://creativecommons.org/licenses/by/4.0/.Bearing vibration signals contain non-linear and non-stationary features due to instantaneous variations in the operation of rotating machinery. It is important to characterize and analyze the complexity change of the bearing vibration signals so that bearing health conditions can be accurately identified. Entropy measures are non-linear indicators that are applicable to the time series complexity analysis for machine fault diagnosis. In this paper, an improved entropy measure, termed Adaptive Multiscale Weighted Permutation Entropy (AMWPE), is proposed. Then, a new rolling bearing fault diagnosis method is developed based on the AMWPE and multi-class SVM. For comparison, experimental bearing data are analyzed using the AMWPE, compared with the conventional entropy measures, where a multi-class SVM is adopted for fault type classification. Moreover, the robustness of different entropy measures is further studied for the analysis of noisy signals with various Signal-to-Noise Ratios (SNRs). The experimental results have demonstrated the effectiveness of the proposed method in fault diagnosis of rolling bearing under different fault types, severity degrees, and SNR levels.Peer reviewedFinal Accepted Versio
Iterative Object and Part Transfer for Fine-Grained Recognition
The aim of fine-grained recognition is to identify sub-ordinate categories in
images like different species of birds. Existing works have confirmed that, in
order to capture the subtle differences across the categories, automatic
localization of objects and parts is critical. Most approaches for object and
part localization relied on the bottom-up pipeline, where thousands of region
proposals are generated and then filtered by pre-trained object/part models.
This is computationally expensive and not scalable once the number of
objects/parts becomes large. In this paper, we propose a nonparametric
data-driven method for object and part localization. Given an unlabeled test
image, our approach transfers annotations from a few similar images retrieved
in the training set. In particular, we propose an iterative transfer strategy
that gradually refine the predicted bounding boxes. Based on the located
objects and parts, deep convolutional features are extracted for recognition.
We evaluate our approach on the widely-used CUB200-2011 dataset and a new and
large dataset called Birdsnap. On both datasets, we achieve better results than
many state-of-the-art approaches, including a few using oracle (manually
annotated) bounding boxes in the test images.Comment: To appear in ICME 2017 as an oral pape
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