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Hongqing He

Publications and source records attributed to Hongqing He.

2 recordsLinked to original sources

Global-Graph Guided and Local-Graph Weighted Contrastive Learning for Unified Clustering on Incomplete and Noise Multi-View Data

Recently, contrastive learning (CL) plays an important role in exploring complementary information for multi-view clustering (MVC) and has attracted increasing attention. Nevertheless, real-world multi-view data suffer from data incompleteness or noise, resulting in rare-paired samples or mis-paired samples which significantly challenges the effectiveness of CL-based MVC. That is, rare-paired issue prevents MVC from extracting sufficient multi-view complementary information, and mis-paired issue causes contrastive learning to optimize the model in the wrong direction. To address these issues, we propose a unified CL-based MVC framework for enhancing clustering effectiveness on incomplete and noise multi-view data. First, to overcome the rare-paired issue, we design a global-graph guided contrastive learning, where all view samples construct a global-view affinity graph to form new sample pairs for fully exploring complementary information. Second, to mitigate the mis-paired issue, we propose a local-graph weighted contrastive learning, which leverages local neighbors to generate pair-wise weights to adaptively strength or weaken the pair-wise contrastive learning. Our method is imputation-free and can be integrated into a unified global-local graph-guided contrastive learning framework. Extensive experiments on both incomplete and noise settings of multi-view data demonstrate that our method achieves superior performance compared with state-of-the-art approaches.

cs.LG

The Statistical and Numerical Study of the Longitudinally Asymmetric Distribution of Solar Proton Events Affecting the Earth Environment of 1996-2011

Large solar proton events (SPEs) affect the solar-terrestrial space environment and become a very important aspect in space weather research. In this work, we statistically investigate 78 solar proton events of 1996-2011 and find that there exists a longitudinally asymmetric distribution of flare sources of the solar proton events observed near 1 AU, namely, with the same longitude separation between magnetic field line footpoint of observer and flare sources, the number of the solar proton events originating from sources located at eastern side of the nominal magnetic footpoint of observer is much larger than that of the solar proton events originating from sources located at western side. A complete model calculation of solar energetic particle (SEP) propagation in the three-dimensional Parker interplanetary magnetic field is presented to give a numerical explanation for this longitudinally asymmetric distribution phenomenon. We find that the longitudinally asymmetric distribution of solar proton events results from the east-west azimuthal asymmetry in the topology of the Parker interplanetary magnetic field as well as the effects of perpendicular diffusion on the transport of SEPs in the heliosphere. Our results would be valuable in understanding the solar-terrestrial relations and useful in space weather forecasting.

astro-ph.HE