71 research outputs found
SnapMix: Semantically Proportional Mixing for Augmenting Fine-grained Data
Data mixing augmentation has proved effective in training deep models. Recent
methods mix labels mainly based on the mixture proportion of image pixels. As
the main discriminative information of a fine-grained image usually resides in
subtle regions, methods along this line are prone to heavy label noise in
fine-grained recognition. We propose in this paper a novel scheme, termed as
Semantically Proportional Mixing (SnapMix), which exploits class activation map
(CAM) to lessen the label noise in augmenting fine-grained data. SnapMix
generates the target label for a mixed image by estimating its intrinsic
semantic composition, and allows for asymmetric mixing operations and ensures
semantic correspondence between synthetic images and target labels. Experiments
show that our method consistently outperforms existing mixed-based approaches
on various datasets and under different network depths. Furthermore, by
incorporating the mid-level features, the proposed SnapMix achieves top-level
performance, demonstrating its potential to serve as a solid baseline for
fine-grained recognition. Our code is available at
https://github.com/Shaoli-Huang/SnapMix.git.Comment: Accepted by AAAI202
Research and Modeling of the Bidirectional Half-Bridge Current-Doubler DC/DC Converter
Due to its high step-up voltage ratio, high utilization rate, and good stability, the bidirectional half-bridge current-doubler topology is widely used in lithium battery system. This paper will further analyze the bidirectional half-bridge current-doubler topology. Taking into account the fact that the current is not equal to the two times current inductance may lead to a greater transformer magnetizing current leaving the transformer core saturation occurring. This paper will focus on the circuit modeling of steady-state analysis and small signal analysis, analyzing the influence parameters for the inductor current by steady-state model and analyzing the stability of the system by the small signal model. The PID controllers and soft start algorithm are designed. Then the influence of circuit parameters on the steady state and the effect of soft start algorithm is verified, and finally the function of the soft start algorithm is achieved by the experimental prototype
Horizontal Pyramid Matching for Person Re-identification
Despite the remarkable recent progress, person re-identification (Re-ID)
approaches are still suffering from the failure cases where the discriminative
body parts are missing. To mitigate such cases, we propose a simple yet
effective Horizontal Pyramid Matching (HPM) approach to fully exploit various
partial information of a given person, so that correct person candidates can be
still identified even even some key parts are missing. Within the HPM, we make
the following contributions to produce a more robust feature representation for
the Re-ID task: 1) we learn to classify using partial feature representations
at different horizontal pyramid scales, which successfully enhance the
discriminative capabilities of various person parts; 2) we exploit average and
max pooling strategies to account for person-specific discriminative
information in a global-local manner. To validate the effectiveness of the
proposed HPM, extensive experiments are conducted on three popular benchmarks,
including Market-1501, DukeMTMC-ReID and CUHK03. In particular, we achieve mAP
scores of 83.1%, 74.5% and 59.7% on these benchmarks, which are the new
state-of-the-arts. Our code is available on GithubComment: Accepted by AAAI 201
CAFE Learning to Condense Dataset by Aligning Features
Dataset condensation aims at reducing the network training effort through
condensing a cumbersome training set into a compact synthetic one.
State-of-the-art approaches largely rely on learning the synthetic data by
matching the gradients between the real and synthetic data batches. Despite the
intuitive motivation and promising results, such gradient-based methods, by
nature, easily overfit to a biased set of samples that produce dominant
gradients, and thus lack global supervision of data distribution. In this
paper, we propose a novel scheme to Condense dataset by Aligning FEatures
(CAFE), which explicitly attempts to preserve the real-feature distribution as
well as the discriminant power of the resulting synthetic set, lending itself
to strong generalization capability to various architectures. At the heart of
our approach is an effective strategy to align features from the real and
synthetic data across various scales, while accounting for the classification
of real samples. Our scheme is further backed up by a novel dynamic bi-level
optimization, which adaptively adjusts parameter updates to prevent
over-/under-fitting. We validate the proposed CAFE across various datasets, and
demonstrate that it generally outperforms the state of the art: on the SVHN
dataset, for example, the performance gain is up to 11%. Extensive experiments
and analyses verify the effectiveness and necessity of proposed designs.Comment: The manuscript has been accepted by CVPR-2022
PARTNER: Level up the Polar Representation for LiDAR 3D Object Detection
Recently, polar-based representation has shown promising properties in
perceptual tasks. In addition to Cartesian-based approaches, which separate
point clouds unevenly, representing point clouds as polar grids has been
recognized as an alternative due to (1) its advantage in robust performance
under different resolutions and (2) its superiority in streaming-based
approaches. However, state-of-the-art polar-based detection methods inevitably
suffer from the feature distortion problem because of the non-uniform division
of polar representation, resulting in a non-negligible performance gap compared
to Cartesian-based approaches. To tackle this issue, we present PARTNER, a
novel 3D object detector in the polar coordinate. PARTNER alleviates the
dilemma of feature distortion with global representation re-alignment and
facilitates the regression by introducing instance-level geometric information
into the detection head. Extensive experiments show overwhelming advantages in
streaming-based detection and different resolutions. Furthermore, our method
outperforms the previous polar-based works with remarkable margins of 3.68% and
9.15% on Waymo and ONCE validation set, thus achieving competitive results over
the state-of-the-art methods.Comment: ICCV 202
Bioinformatics analyses of gene expression profile to identify pathogenic mechanisms for COVID-19 infection and cutaneous lupus erythematosus
ObjectiveThe global mortality rates have surged due to the ongoing coronavirus disease 2019 (COVID-19), leading to a worldwide catastrophe. Increasing incidents of patients suffering from cutaneous lupus erythematosus (CLE) exacerbations after either contracting COVID-19 or getting immunized against it, have been observed in recent research. However, the precise intricacies that prompt this unexpected complication are yet to be fully elucidated. This investigation seeks to probe into the molecular events inciting this adverse outcome.MethodGene expression patterns from the Gene Expression Omnibus (GEO) database, specifically GSE171110 and GSE109248, were extracted. We then discovered common differentially expressed genes (DEGs) in both COVID-19 and CLE. This led to the creation of functional annotations, formation of a protein-protein interaction (PPI) network, and identification of key genes. Furthermore, regulatory networks relating to these shared DEGs and significant genes were constructed.ResultWe identified 214 overlapping DEGs in both COVID-19 and CLE datasets. The following functional enrichment analysis of these DEGs highlighted a significant enrichment in pathways related to virus response and infectious disease in both conditions. Next, a PPI network was constructed using bioinformatics tools, resulting in the identification of 5 hub genes. Finally, essential regulatory networks including transcription factor-gene and miRNA-gene interactions were determined.ConclusionOur findings demonstrate shared pathogenesis between COVID-19 and CLE, offering potential insights for future mechanistic investigations. And the identification of common pathways and key genes in these conditions may provide novel avenues for research
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