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457 results on '"Wei, Dandan"'

5. Addressing incomplete tile phenomena in image tiling: Introducing the grid six-intersection model

Author

Zhang Ling, Yu Jinsongdi, Tong Ruiju, Wei Dandan, and Fan Yu

Subjects
imagery, grid, tiling, topology, Geology, QE1-996.5
Abstract

With the continuous development of Earth Observation technology, resolution of imagery and gridded data has significantly increased, leading to a rapid increase in data volume. To efficiently acquire and analyze these vast amounts of imagery and gridded data, image tiling technology has been developed to effectively access data of interested areas. Tiling technology divides large-scale image data into smaller tiles, providing fast, accurate, and efficient access support for imagery and gridded data. The spatial grid model, as the foundational framework of the new generation of geographic spatial information, plays a critical role in the retrieval, integration, services, and applications of imagery and gridded data resources. When tiling image data based on the spatial grid model, it always generates both complete and incomplete tiles. Particularly, when conducting image tile retrieval using the same rule-based grid in the retrieval area, incomplete tile phenomena along the boundary regions of the retrieved images often occur, resulting in gaps within the retrieval area. To tackle this issue, in this study, we present a new topological model called the Grid Six-Intersection Model (G-6IM), specifically designed for regular rectangular grids, to accurately represent boundary issues in image tiling. Through a practical case study, we demonstrate the effectiveness and practical application potential of the proposed G-6IM model, providing new insights and guidance for the improvement and optimization of imagery and gridded data tiling technology.

Published
2024
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8. Worry and Fear during the COVID-19 Epidemic Normalization: Analyzing Prevalence and Risk Factors among 182,991 High School Students in China

Author

Xu, Qingqing, Fan, Keliang, Wei, Dandan, Liu, Pengling, Wang, Juan, Wang, Xian, Lou, Xiaomin, Lin, Hualiang, Wang, Chongjian, Wu, Cuiping, and Mao, Zhenxing

Abstract

It is worth paying attention to the level of worry and fear of students during the normalization of the epidemic. We conducted the cross-sectional study that included 182,991 high school students using an online survey to assess worry and fear levels and its influencing factors in three cities in Henan Province, China, from May 21 to May 27, 2021. Worry and fear levels were measured using a five-item Likert-type scale. Multinomial logistic regression was used to analyze the risk factors. Approximately 65.42% of students reported being high worry about the coronavirus disease 2019 (COVID-19) epidemic, and about 41.44% of students reported being high fear about the COVID-19 epidemic. In addition, compared with female, male had lower odds of suffering from a high worry, and compared with senior high school students, junior high school students were more likely to suffer from a high worry. Students lived in rural had highest odds increased likelihood of high worry. Similar results in fear levels. During the normalization period of the COVID-19 epidemic, many students have high levels of worry and fear. This study has implications for potential influencers of worry and fear levels in follow-up work.

Published
2023
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