168 research outputs found
eMotions: A Large-Scale Dataset for Emotion Recognition in Short Videos
Nowadays, short videos (SVs) are essential to information acquisition and
sharing in our life. The prevailing use of SVs to spread emotions leads to the
necessity of emotion recognition in SVs. Considering the lack of SVs emotion
data, we introduce a large-scale dataset named eMotions, comprising 27,996
videos. Meanwhile, we alleviate the impact of subjectivities on labeling
quality by emphasizing better personnel allocations and multi-stage
annotations. In addition, we provide the category-balanced and test-oriented
variants through targeted data sampling. Some commonly used videos (e.g.,
facial expressions and postures) have been well studied. However, it is still
challenging to understand the emotions in SVs. Since the enhanced content
diversity brings more distinct semantic gaps and difficulties in learning
emotion-related features, and there exists information gaps caused by the
emotion incompleteness under the prevalently audio-visual co-expressions. To
tackle these problems, we present an end-to-end baseline method AV-CPNet that
employs the video transformer to better learn semantically relevant
representations. We further design the two-stage cross-modal fusion module to
complementarily model the correlations of audio-visual features. The EP-CE
Loss, incorporating three emotion polarities, is then applied to guide model
optimization. Extensive experimental results on nine datasets verify the
effectiveness of AV-CPNet. Datasets and code will be open on
https://github.com/XuecWu/eMotions
Jets Downstream of Collisionless Shocks
The magnetosheath flow may take the form of large amplitude, yet spatially localized, transient increases in dynamic pressure, known as "magnetosheath jets" or "plasmoids" among other denominations. Here, we describe the present state of knowledge with respect to such jets, which are a very common phenomenon downstream of the quasi-parallel bow shock. We discuss their properties as determined by satellite observations (based on both case and statistical studies), their occurrence, their relation to solar wind and foreshock conditions, and their interaction with and impact on the magnetosphere. As carriers of plasma and corresponding momentum, energy, and magnetic flux, jets bear some similarities to bursty bulk flows, which they are compared to. Based on our knowledge of jets in the near Earth environment, we discuss the expectations for jets occurring in other planetary and astrophysical environments. We conclude with an outlook, in which a number of open questions are posed and future challenges in jet research are discussed.Peer reviewe
Towards Online Multiresolution Community Detection in Large-Scale Networks
The investigation of community structure in networks has aroused great interest in multiple disciplines. One of the challenges is to find local communities from a starting vertex in a network without global information about the entire network. Many existing methods tend to be accurate depending on a priori assumptions of network properties and predefined parameters. In this paper, we introduce a new quality function of local community and present a fast local expansion algorithm for uncovering communities in large-scale networks. The proposed algorithm can detect multiresolution community from a source vertex or communities covering the whole network. Experimental results show that the proposed algorithm is efficient and well-behaved in both real-world and synthetic networks
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