There is an increasing demand for supporting high-quality real-time audiovisual services for the next generation wired and wireless networks. However, due to variety of bandwidths of different networks, it is a great ...There is an increasing demand for supporting high-quality real-time audiovisual services for the next generation wired and wireless networks. However, due to variety of bandwidths of different networks, it is a great challenge for deployment. In this paper, a novel high-definition (HD) video transmission system was proposed which depends upon reliable compound multicast protocols and QoS control over the various kinds of networks. This system detects client's network condition and assigns it to a proper proxy. Each proxy is capable of detecting network parameters and adaptively tuning such transport parameters as bit rate, video resolution, frame rate and QoS mechanisms to this condition. It also provides FEC error recovery under consideration of characteristics of MPEG4 video codec. Our simulation demonstrates that different network clients such as ADSL, CERNET, and CERNET2 can receive more video reliability with less delay.展开更多
Heading date is one of the most important traits for rice adaption to different cultivation areas and crop seasons. In this study, two single segment substitution lines(SSSLs), W31-41-61-3-11-3-6-7(W31-SSSL) and W32-5...Heading date is one of the most important traits for rice adaption to different cultivation areas and crop seasons. In this study, two single segment substitution lines(SSSLs), W31-41-61-3-11-3-6-7(W31-SSSL) and W32-59-80-2-11-1-10(W32-SSSL) with substituted intervals derived from the donor parents IR66897 B(W31) and IR66167-27-5-1-6(W32), respectively, with Huajingxian 74(HTX74) were found to comprise a gene for extremely late-heading date, and the gene was tentatively designated as Hd-6-2. Two secondary F2 segregating populations were developed by crossing the two heterozygous SSSLs with HJX74 to map Hd-6-2 gene. According to phenotype analysis of the two mapping populations, the late heading date trait was controlled by a major recessive gene. In the segregation population derived from W31-SSSL, Hd-6-2 was mapped on chromosome 6 between PSM677 and RM204 with the genetic distances of 1.3 and 2.7 c M, respectively. In the population of W32-SSSL, the gene for heading date was mapped to the similar region as Hd-6-2 and co-segregated with PSM672. The sequence alignment of Hd3 a in the coding domains and promoter regions of HJX74 and W31-SSSL are completely consistent, whereas there was a great difference between W32-SSSL and HJX74, suggesting that Hd3 a could hardly be the main cause of the heading date variation in W31-SSSL, but it was probably the main reason for the change of heading stage in W32-SSSL.展开更多
A lane-level intersection map is a cornerstone in high-definition(HD) traffic network maps for autonomous driving and high-precision intelligent transportation systems applications such as traffic management and contr...A lane-level intersection map is a cornerstone in high-definition(HD) traffic network maps for autonomous driving and high-precision intelligent transportation systems applications such as traffic management and control, and traffic accident evaluation and prevention. Mapping an HD intersection is time-consuming, labor-intensive, and expensive with conventional methods. In this paper, we used a low-channel roadside light detection and range sensor(LiDAR) to automatically and dynamically generate a lane-level intersection, including the signal phases, geometry, layout, and lane directions. First, a mathematical model was proposed to describe the topology and detail of a lane-level intersection. Second, continuous and discontinuous traffic object trajectories were extracted to identify the signal phases and times. Third, the layout, geometry, and lane direction were identified using the convex hull detection algorithm for trajectories. Fourth, a sliding window algorithm was presented to detect the lane marking and extract the lane, and the virtual lane connecting the inbound and outbound of the intersection were generated using the vehicle trajectories within the intersection and considering the traffic rules. In the field experiment, the mean absolute estimation error is 2 s for signal phase and time identification. The lane marking identification Precision and Recall are96% and 94.12%, respectively. Compared with the satellite-based,MMS-based, and crowdsourcing-based lane mapping methods,the average lane location deviation is 0.2 m and the update period is less than one hour by the proposed method with low-channel roadside LiDAR.展开更多
With the growth in the vehicle industry,autonomous driving has become a hot topic worldwide and has attracted increasing attention from both industrial and academic sectors.Maps,as pivotal geospatial information carri...With the growth in the vehicle industry,autonomous driving has become a hot topic worldwide and has attracted increasing attention from both industrial and academic sectors.Maps,as pivotal geospatial information carriers,play a vital role in route planning and navigation service.Compared with conventional maps,high-definition(HD)maps possesses higher precision,richer information,and various services and are regarded as critical infrastructure for autonomous driving.However,heterogeneous HD map data standards and models have different characteristics and advantages,and thus they rarely meet all autonomous driving requirements for different driving objectives.This research presents an interoperable map data model,the Open HD Map Service Model(OHDMSM),to provide a reference for HD map development.The designed OHDMSM,which contains three data layers and a set of corresponding interfaces,demonstrates high interoperability for HD map data fusion and application.As a proof of concept,an HD map data system is implemented with all functions following the designed data model and interfaces of OHDMSM.The design and development of OHDMSM data structures,interfaces and systems will benefit data requesting,updating,and interoperation for HD map data worldwide,which can be helpful for developing autonomous driving and intelligent transportation in the Digital Earth.展开更多
Gray mapping is a well-known way to improve the performance of regular constellation modulation,but it is challenging to be applied directly for irregular alternative.To address this issue,in this paper,a unified bit-...Gray mapping is a well-known way to improve the performance of regular constellation modulation,but it is challenging to be applied directly for irregular alternative.To address this issue,in this paper,a unified bit-to-symbol mapping method is designed for generalized constellation modulation(i.e.,regular and irregular shaping).The objective of the proposed approach is to minimize the average bit error probability by reducing the hamming distance(HD)of symbols with larger values of pairwise error probability.Simulation results show that the conventional constellation modulation(i.e.,phase shift keying and quadrature amplitude modulation(QAM)with the proposed mapping rule yield the same performance as that of classical gray mapping.Moreover,the recently developed golden angle modulation(GAM)with the proposed mapping method is capable of providing around1 d B gain over the conventional mapping counterpart and offers comparable performance to QAM with Gray mapping.展开更多
Plant trichomes originate from epidermal cells.In this work,we demonstrated that a homeodomain-leucine zipper(HD-Zip)gene,Gh_A06G1283(Gh HD-1A),was related to the leaf trichome trait in allotetraploid cotton and could...Plant trichomes originate from epidermal cells.In this work,we demonstrated that a homeodomain-leucine zipper(HD-Zip)gene,Gh_A06G1283(Gh HD-1A),was related to the leaf trichome trait in allotetraploid cotton and could be a candidate gene for the T_1 locus.The ortholog of GhHD-1A in the hairless accession Gossypium barbadense cv.Hai7124 was interrupted by a long terminal repeat(LTR)retrotransposon,while GhHD-1A worked well in the hairy accession Gossypium hirsutum acc.T586.Sequence and phylogenetic analysis showed that GhHD-1A belonged to the HD-Zip IV gene family,which mainly regulated epidermis hair development in plants.Silencing of GhHD-1A and its homoeologs GhHD-1D in allotetraploid T586and Hai7124 could significantly reduce the density of leaf hairs and affect the expression levels of other genes related to leaf trichome formation.Further analysis found that GhHD-1A mainly regulated trichome initiation on the upper epidermal hairs of leaves in cotton,while the up-regulated expression of GhHD-1A in different organs/tissues also altered epidermal trichome development.This study not only helps to unravel the important roles of GhHD-1A in regulating trichome initiation in cotton,but also provides a reference for exploring the different forms of trichome development in plants.展开更多
High-definition(HD)maps are key components that provide rich topologic and semantic information for decision-making in vehicle autonomous driving systems.A complete ground orthophoto is usually used as the base image ...High-definition(HD)maps are key components that provide rich topologic and semantic information for decision-making in vehicle autonomous driving systems.A complete ground orthophoto is usually used as the base image to construct the HD map.The ground orthophoto is obtained through inverse perspective transformation and image mosaicing.During the image mosaicing,multiple consecutive orthophotos are stitched together using pose information and image registration.In this study,wavelet transform is introduced to the image mosaicing process to alleviate the information loss caused by image overlapping.In the orthophoto wavelet transform,high-frequency and low-frequency components are fused using different strategies to form a complete base image with clearer local details.Experimental results show that the accuracy of the orthophotos generated using this method is improved.展开更多
文摘There is an increasing demand for supporting high-quality real-time audiovisual services for the next generation wired and wireless networks. However, due to variety of bandwidths of different networks, it is a great challenge for deployment. In this paper, a novel high-definition (HD) video transmission system was proposed which depends upon reliable compound multicast protocols and QoS control over the various kinds of networks. This system detects client's network condition and assigns it to a proper proxy. Each proxy is capable of detecting network parameters and adaptively tuning such transport parameters as bit rate, video resolution, frame rate and QoS mechanisms to this condition. It also provides FEC error recovery under consideration of characteristics of MPEG4 video codec. Our simulation demonstrates that different network clients such as ADSL, CERNET, and CERNET2 can receive more video reliability with less delay.
基金financially supported by the National Key Research and Development Program of China (Grant Nos. 2016YFD0100903-9 and 2016YFD0100101-14)the Natural Science Foundation of Shandong Province (Grant No. ZR2014CQ007)the Rice Industry Technology Program of Shandong Province, China (Grant No. SDAIT-17-03)
文摘Heading date is one of the most important traits for rice adaption to different cultivation areas and crop seasons. In this study, two single segment substitution lines(SSSLs), W31-41-61-3-11-3-6-7(W31-SSSL) and W32-59-80-2-11-1-10(W32-SSSL) with substituted intervals derived from the donor parents IR66897 B(W31) and IR66167-27-5-1-6(W32), respectively, with Huajingxian 74(HTX74) were found to comprise a gene for extremely late-heading date, and the gene was tentatively designated as Hd-6-2. Two secondary F2 segregating populations were developed by crossing the two heterozygous SSSLs with HJX74 to map Hd-6-2 gene. According to phenotype analysis of the two mapping populations, the late heading date trait was controlled by a major recessive gene. In the segregation population derived from W31-SSSL, Hd-6-2 was mapped on chromosome 6 between PSM677 and RM204 with the genetic distances of 1.3 and 2.7 c M, respectively. In the population of W32-SSSL, the gene for heading date was mapped to the similar region as Hd-6-2 and co-segregated with PSM672. The sequence alignment of Hd3 a in the coding domains and promoter regions of HJX74 and W31-SSSL are completely consistent, whereas there was a great difference between W32-SSSL and HJX74, suggesting that Hd3 a could hardly be the main cause of the heading date variation in W31-SSSL, but it was probably the main reason for the change of heading stage in W32-SSSL.
基金supported in part by the Scientific Research Project of the Education Department of Jilin Province (JJKH20221020KJ)the National Natural Science Foundation of China (51408257)the Graduate Innovation Fund of Jilin University (101832020CX150)。
文摘A lane-level intersection map is a cornerstone in high-definition(HD) traffic network maps for autonomous driving and high-precision intelligent transportation systems applications such as traffic management and control, and traffic accident evaluation and prevention. Mapping an HD intersection is time-consuming, labor-intensive, and expensive with conventional methods. In this paper, we used a low-channel roadside light detection and range sensor(LiDAR) to automatically and dynamically generate a lane-level intersection, including the signal phases, geometry, layout, and lane directions. First, a mathematical model was proposed to describe the topology and detail of a lane-level intersection. Second, continuous and discontinuous traffic object trajectories were extracted to identify the signal phases and times. Third, the layout, geometry, and lane direction were identified using the convex hull detection algorithm for trajectories. Fourth, a sliding window algorithm was presented to detect the lane marking and extract the lane, and the virtual lane connecting the inbound and outbound of the intersection were generated using the vehicle trajectories within the intersection and considering the traffic rules. In the field experiment, the mean absolute estimation error is 2 s for signal phase and time identification. The lane marking identification Precision and Recall are96% and 94.12%, respectively. Compared with the satellite-based,MMS-based, and crowdsourcing-based lane mapping methods,the average lane location deviation is 0.2 m and the update period is less than one hour by the proposed method with low-channel roadside LiDAR.
基金supported by National Key Research and Development Program of China:[Grant Number 2021YFB2501101]Smart Cities Research Institute(Q-CDA7)at the Hong Kong Polytechnic University:[Grant Number Q-CDA7]Guangdong Science and Technology Strategic Innovation Fund(the Guangdong–Hong Kong-Macao Joint Laboratory Program):Guangdong Science and Technology Strategic Innovation Fund:[Grant Number 2020B12120300092020B1212030009].
文摘With the growth in the vehicle industry,autonomous driving has become a hot topic worldwide and has attracted increasing attention from both industrial and academic sectors.Maps,as pivotal geospatial information carriers,play a vital role in route planning and navigation service.Compared with conventional maps,high-definition(HD)maps possesses higher precision,richer information,and various services and are regarded as critical infrastructure for autonomous driving.However,heterogeneous HD map data standards and models have different characteristics and advantages,and thus they rarely meet all autonomous driving requirements for different driving objectives.This research presents an interoperable map data model,the Open HD Map Service Model(OHDMSM),to provide a reference for HD map development.The designed OHDMSM,which contains three data layers and a set of corresponding interfaces,demonstrates high interoperability for HD map data fusion and application.As a proof of concept,an HD map data system is implemented with all functions following the designed data model and interfaces of OHDMSM.The design and development of OHDMSM data structures,interfaces and systems will benefit data requesting,updating,and interoperation for HD map data worldwide,which can be helpful for developing autonomous driving and intelligent transportation in the Digital Earth.
基金supported in part by the National Key Research and Development Program of China under Grant 2021YFB2900502in part by the National Science Foundation of China under Grant 62001179in part by the Fundamental Research Funds for the Central Universities under Grant 2020kfy XJJS111。
文摘Gray mapping is a well-known way to improve the performance of regular constellation modulation,but it is challenging to be applied directly for irregular alternative.To address this issue,in this paper,a unified bit-to-symbol mapping method is designed for generalized constellation modulation(i.e.,regular and irregular shaping).The objective of the proposed approach is to minimize the average bit error probability by reducing the hamming distance(HD)of symbols with larger values of pairwise error probability.Simulation results show that the conventional constellation modulation(i.e.,phase shift keying and quadrature amplitude modulation(QAM)with the proposed mapping rule yield the same performance as that of classical gray mapping.Moreover,the recently developed golden angle modulation(GAM)with the proposed mapping method is capable of providing around1 d B gain over the conventional mapping counterpart and offers comparable performance to QAM with Gray mapping.
基金supported by the National Natural Science Foundation of China (31471539)the Jiangsu Collaborative Innovation Center for Modern Crop Production Project, China (No.10)
文摘Plant trichomes originate from epidermal cells.In this work,we demonstrated that a homeodomain-leucine zipper(HD-Zip)gene,Gh_A06G1283(Gh HD-1A),was related to the leaf trichome trait in allotetraploid cotton and could be a candidate gene for the T_1 locus.The ortholog of GhHD-1A in the hairless accession Gossypium barbadense cv.Hai7124 was interrupted by a long terminal repeat(LTR)retrotransposon,while GhHD-1A worked well in the hairy accession Gossypium hirsutum acc.T586.Sequence and phylogenetic analysis showed that GhHD-1A belonged to the HD-Zip IV gene family,which mainly regulated epidermis hair development in plants.Silencing of GhHD-1A and its homoeologs GhHD-1D in allotetraploid T586and Hai7124 could significantly reduce the density of leaf hairs and affect the expression levels of other genes related to leaf trichome formation.Further analysis found that GhHD-1A mainly regulated trichome initiation on the upper epidermal hairs of leaves in cotton,while the up-regulated expression of GhHD-1A in different organs/tissues also altered epidermal trichome development.This study not only helps to unravel the important roles of GhHD-1A in regulating trichome initiation in cotton,but also provides a reference for exploring the different forms of trichome development in plants.
基金the National Natural Science Foundation of China(No.U1764264/61873165)the Shanghai Automotive Industry Science and Technology Development Foundation(No.1807)the Guangxi Key Laboratory of Automobile Components and Vehicle Technology Research Project(No.2020GKLACVTKF02)。
文摘High-definition(HD)maps are key components that provide rich topologic and semantic information for decision-making in vehicle autonomous driving systems.A complete ground orthophoto is usually used as the base image to construct the HD map.The ground orthophoto is obtained through inverse perspective transformation and image mosaicing.During the image mosaicing,multiple consecutive orthophotos are stitched together using pose information and image registration.In this study,wavelet transform is introduced to the image mosaicing process to alleviate the information loss caused by image overlapping.In the orthophoto wavelet transform,high-frequency and low-frequency components are fused using different strategies to form a complete base image with clearer local details.Experimental results show that the accuracy of the orthophotos generated using this method is improved.
