Langshan, a monoclinic mountain, which started to uplift since Oligocene, bounds the northwest margin of the Hetao Basin. The continuous activity of the active normal Langshan range- front fault forms the typical basi...Langshan, a monoclinic mountain, which started to uplift since Oligocene, bounds the northwest margin of the Hetao Basin. The continuous activity of the active normal Langshan range- front fault forms the typical basin-and-range landform in Langshan area and controls the landform evolution of Langshan. Langshan is an ideal place to study relationship between quantitative geomor- phological index and active deformation. According to study on knickpoints, fitting on longitudinal channel profiles and steepness index, we demonstrate that the main controlling factors on distribution of normalized steepness index of channels are not climate （precipitation）, lithology, sediment flux, but tectonic factor, or the activity of Langshan range-front fault. The short channels in southeast flank, whose lengths are shorter than 16 km, may be still in the non-steady status. If not considering these short channels, the distribution of normalized steepness index along the Langshan range-front fault appears like M-shape pattern, while the normalized steepness index in the middle section is higher than those at both ends. This pattern is well consistent with geometrical segmentation model of the Langshan range-front fault. Combining previous active tectonic research on Langshan range-front fault, which demonstrates the Langshan range-front fault has been in the stage of linkup, we reasonably infer the Langshan range-front fault now is the result of linkup of both fault which continuously bilaterally ex- tended independently. Our tectonic geomorphological study also supports the conclusion that the Langshan range-front fault has been in the stage of linkup. The formation of several knickpoints due to tectonic factor may have been caused by slip-rate variation because of linkup of both independent faults. Based on cognition above, we also proposed the geological and geomorphological evolutionary model of the Langshan range-front fault since Oligocene.展开更多
An accurate and up-to-date High Definition(HD)Map is critical for an intelligent vehicle to drive safely and effectively.Although research in this area is growing,there is still a lack of clarity in defining HD maps f...An accurate and up-to-date High Definition(HD)Map is critical for an intelligent vehicle to drive safely and effectively.Although research in this area is growing,there is still a lack of clarity in defining HD maps for intelligent connected vehicles(ICVs).This gap in knowledge is particularly challenging for new researchers,who often struggle to find suitable HD map datasets due to a lack of comprehensive reviews on current HD map products,as far as the authors’knowledge.Thus,this article aims to bridge this gap by providing a thorough analysis of the core ideas of HD map technology.Initially,this paper presents the brief history of HD map.Following this,it describes the taxonomy and ontology of HD maps,complete with the HD map contents and existing standards.An insight into the mapping process is also given by discussing the algorithms used for creating and updating HD maps.This manuscript also lists current HD map products and the open-sourced dataset available for interested researchers in this space.As part of this study,the authors also describe common applications of HAD maps in ICVs.Finally,the article highlight the key research challenges and potential future directions in this field.Addressing these challenges is vital for the advancement and integration of HD maps for ICVs.展开更多
基金funded jointly by the National Natural Science Foundation of China (Nos. 41402187, 41372220, 41590861, 41661134011)
文摘Langshan, a monoclinic mountain, which started to uplift since Oligocene, bounds the northwest margin of the Hetao Basin. The continuous activity of the active normal Langshan range- front fault forms the typical basin-and-range landform in Langshan area and controls the landform evolution of Langshan. Langshan is an ideal place to study relationship between quantitative geomor- phological index and active deformation. According to study on knickpoints, fitting on longitudinal channel profiles and steepness index, we demonstrate that the main controlling factors on distribution of normalized steepness index of channels are not climate （precipitation）, lithology, sediment flux, but tectonic factor, or the activity of Langshan range-front fault. The short channels in southeast flank, whose lengths are shorter than 16 km, may be still in the non-steady status. If not considering these short channels, the distribution of normalized steepness index along the Langshan range-front fault appears like M-shape pattern, while the normalized steepness index in the middle section is higher than those at both ends. This pattern is well consistent with geometrical segmentation model of the Langshan range-front fault. Combining previous active tectonic research on Langshan range-front fault, which demonstrates the Langshan range-front fault has been in the stage of linkup, we reasonably infer the Langshan range-front fault now is the result of linkup of both fault which continuously bilaterally ex- tended independently. Our tectonic geomorphological study also supports the conclusion that the Langshan range-front fault has been in the stage of linkup. The formation of several knickpoints due to tectonic factor may have been caused by slip-rate variation because of linkup of both independent faults. Based on cognition above, we also proposed the geological and geomorphological evolutionary model of the Langshan range-front fault since Oligocene.
基金National Natural Science Foundation of China(U22A20104,52102464)Beijing Natural Science Foundation(L231008)Young Elite Scientist Sponsorship Program By BAST(BYESS2022153).
文摘An accurate and up-to-date High Definition(HD)Map is critical for an intelligent vehicle to drive safely and effectively.Although research in this area is growing,there is still a lack of clarity in defining HD maps for intelligent connected vehicles(ICVs).This gap in knowledge is particularly challenging for new researchers,who often struggle to find suitable HD map datasets due to a lack of comprehensive reviews on current HD map products,as far as the authors’knowledge.Thus,this article aims to bridge this gap by providing a thorough analysis of the core ideas of HD map technology.Initially,this paper presents the brief history of HD map.Following this,it describes the taxonomy and ontology of HD maps,complete with the HD map contents and existing standards.An insight into the mapping process is also given by discussing the algorithms used for creating and updating HD maps.This manuscript also lists current HD map products and the open-sourced dataset available for interested researchers in this space.As part of this study,the authors also describe common applications of HAD maps in ICVs.Finally,the article highlight the key research challenges and potential future directions in this field.Addressing these challenges is vital for the advancement and integration of HD maps for ICVs.
