Background: The stem curve of standing trees is an essential parameter for accurate estimation of stem volume.This study aims to directly quantify the occlusions within the single-scan terrestrial laser scanning(TLS) ...Background: The stem curve of standing trees is an essential parameter for accurate estimation of stem volume.This study aims to directly quantify the occlusions within the single-scan terrestrial laser scanning(TLS) data,evaluate its correlation with the accuracy of the retrieved stem curves, and subsequently, to assess the capacity of single-scan TLS to estimate stem curves.Methods: We proposed an index, occlusion rate, to quantify the occlusion level in TLS data. We then analyzed three influencing factors for the occlusion rate: the percentage of basal area near the scanning center, the scanning distance and the source of occlusions. Finally, we evaluated the effects of occlusions on stem curve estimates from single-scan TLS data.Results: The results showed that the correlations between the occlusion rate and the stem curve estimation accuracies were strong(r = 0.60–0.83), so was the correlations between the occlusion rate and its influencing factors(r = 0.84–0.99). It also showed that the occlusions from tree stems were the main factor of the low detection rate of stems, while the non-stem components mainly influenced the completeness of the retrieved stem curves.Conclusions: Our study demonstrates that the occlusions significantly affect the accuracy of stem curve retrieval from the single-scan TLS data in a typical-size(32 m × 32 m) forest plot. However, the single-scan mode has the capacity to accurately estimate the stem curve in a small forest plot(< 10 m × 10 m) or a plot with a lower occlusion rate, such as less than 35% in our tested datasets. The findings from this study are useful for guiding the practice of retrieving forest parameters using single-scan TLS data.展开更多
The concept of“STEM+”integrates art,humanistic literacy,and social values in the traditional STEM education concept,advocates cross-disciplinary integration,and aims to cultivate compound talents equipped to tackle ...The concept of“STEM+”integrates art,humanistic literacy,and social values in the traditional STEM education concept,advocates cross-disciplinary integration,and aims to cultivate compound talents equipped to tackle future challenges.In 2022,the Ministry of Education issued the“Compulsory Education Information Technology Curriculum(2022 Edition),”emphasizing the core literacy of information science and technology and the integration of interdisciplinary disciplines,and encouraging the teaching mode suitable for discipline characteristics.The 6E teaching mode is a student-centered teaching strategy characterized by active exploration and cross-disciplinary integration.This article innovatively designed the“STEM+”6E teaching mode,which is applied to junior high school information technology teaching,which can better achieve core literacy teaching goals.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.41671414,41971380,41331171 and 41171265)the National Key Research and Development Program of China(No.2016YFB0501404)
文摘Background: The stem curve of standing trees is an essential parameter for accurate estimation of stem volume.This study aims to directly quantify the occlusions within the single-scan terrestrial laser scanning(TLS) data,evaluate its correlation with the accuracy of the retrieved stem curves, and subsequently, to assess the capacity of single-scan TLS to estimate stem curves.Methods: We proposed an index, occlusion rate, to quantify the occlusion level in TLS data. We then analyzed three influencing factors for the occlusion rate: the percentage of basal area near the scanning center, the scanning distance and the source of occlusions. Finally, we evaluated the effects of occlusions on stem curve estimates from single-scan TLS data.Results: The results showed that the correlations between the occlusion rate and the stem curve estimation accuracies were strong(r = 0.60–0.83), so was the correlations between the occlusion rate and its influencing factors(r = 0.84–0.99). It also showed that the occlusions from tree stems were the main factor of the low detection rate of stems, while the non-stem components mainly influenced the completeness of the retrieved stem curves.Conclusions: Our study demonstrates that the occlusions significantly affect the accuracy of stem curve retrieval from the single-scan TLS data in a typical-size(32 m × 32 m) forest plot. However, the single-scan mode has the capacity to accurately estimate the stem curve in a small forest plot(< 10 m × 10 m) or a plot with a lower occlusion rate, such as less than 35% in our tested datasets. The findings from this study are useful for guiding the practice of retrieving forest parameters using single-scan TLS data.
基金2024 Chongqing Normal University Graduate Research Innovation Project“Construction and Application of Information Technology Knowledge Map based on the Three-Layer Architecture”(CYS240395)。
文摘The concept of“STEM+”integrates art,humanistic literacy,and social values in the traditional STEM education concept,advocates cross-disciplinary integration,and aims to cultivate compound talents equipped to tackle future challenges.In 2022,the Ministry of Education issued the“Compulsory Education Information Technology Curriculum(2022 Edition),”emphasizing the core literacy of information science and technology and the integration of interdisciplinary disciplines,and encouraging the teaching mode suitable for discipline characteristics.The 6E teaching mode is a student-centered teaching strategy characterized by active exploration and cross-disciplinary integration.This article innovatively designed the“STEM+”6E teaching mode,which is applied to junior high school information technology teaching,which can better achieve core literacy teaching goals.
