随着4G网络的普及以及5G建设工作的开展,无线网络规划已经成为4G,5G网络建设中十分重要的一项工作。无线网络规划的合理性会直接影响移动网络的建设规模和用户感知。在无线网络规划工作中,可以利用无线网络规划软件作为辅助工具,从而给...随着4G网络的普及以及5G建设工作的开展,无线网络规划已经成为4G,5G网络建设中十分重要的一项工作。无线网络规划的合理性会直接影响移动网络的建设规模和用户感知。在无线网络规划工作中,可以利用无线网络规划软件作为辅助工具,从而给出更加合理的设计规划。因此,无线网络规划地理信息相关技术的研究及功能的实现对网络规划具有重要意义。移动网络规划软件从软件操作界面、覆盖类型划分、多种规划方式、数据存储等几个方面进行设计开发,通过Microsoft Visual Studio 2019作为开发工具,C#作为开发编程语言,使用免费、开源的.NET地图控件GMap.NET进行二次开发。文章结合网络规划的具体流程,介绍了开发移动网络规划软件中用到的GMap.NET的相关接口、类型及关键方法。展开更多
同步定位与建图(Simultaneous Localization and Mapping, SLAM)是自动驾驶领域的关键技术之一。基于差异化的应用场景、传感器和算法,主流SLAM实现方法分为视觉SLAM、激光SLAM和多传感器SLAM等,其性能的优化方向主要基于传感器性能,算...同步定位与建图(Simultaneous Localization and Mapping, SLAM)是自动驾驶领域的关键技术之一。基于差异化的应用场景、传感器和算法,主流SLAM实现方法分为视觉SLAM、激光SLAM和多传感器SLAM等,其性能的优化方向主要基于传感器性能,算法策略以及估计方法。室内场景下,视觉SLAM方法因视觉传感器的视野范围有限且对光线明暗,性能受限于环境变化。多线激光雷达因价格昂贵,不适宜广泛应用。多传感器融合的方案,因部分视觉传感器采集环境特征信息丰富而存在系统运行的时延问题且融合设计复杂度高。针对以上问题,本文提出了一种基于单线激光雷达,感知算法与全局路径规划算法融合的SLAM与自主导航方案,设计软件与硬件结合的系统框架,所实现的运动系统在室内场景下高速获取环境信息,能够获取良好的建图性能并完成低时延自主导航。首先,本文系统利用IMU对单线激光雷达采集的回波数据做畸变矫正,对激光雷达数据采用Gmapping算法处理,并对各传感器的坐标系关系做精确计算和转换,而后采用Djikstra算法作为全局路径规划算法来实现运动系统的自主导航。最终通过实验,利用ROS系统,NVIDIA-Jetson-Nano,IMU、2D-Lidar等,在实际环境中实现了算法模型与系统构建,室内场景中建图效果良好,机器车在同步定位与建图过程中自主导航,验证了本文方案及系统的可靠性与有效性。展开更多
Flowering time is important for adaptation of soybean(Glycine max)to different environments.Here,we conducted a genome-wide association study of flowering time using a panel of 1490 cultivated soybean accessions.We id...Flowering time is important for adaptation of soybean(Glycine max)to different environments.Here,we conducted a genome-wide association study of flowering time using a panel of 1490 cultivated soybean accessions.We identified three strong signals at the qFT02-2 locus(Chr02:12037319–12238569),which were associated with flowering time in three environments:Gongzhuling,Mengcheng,and Nanchang.By analyzing linkage disequilibrium,gene expression patterns,gene annotation,and the diversity of variants,we identified an AP1 homolog as the candidate gene for the qFT02-2 locus,which we named GmAP1d.Only one nonsynonymous polymorphism existed among 1490 soybean accessions at position Chr02:12087053.Accessions carrying the Chr02:12087053-T allele flowered significantly earlier than those carrying the Chr02:12087053-A allele.Thus,we developed a cleaved amplified polymorphic sequence(CAPS)marker for the SNP at Chr02:12087053,which is suitable for marker-assisted breeding of flowering time.Knockout of GmAP1d in the‘Williams 82’background by gene editing promoted flowering under long-day conditions,confirming that GmAP1d is the causal gene for qFT02-2.An analysis of the region surrounding GmAP1d revealed that GmAP1d was artificially selected during the genetic improvement of soybean.Through stepwise selection,the proportion of modern cultivars carrying the Chr02:12087053-T allele has increased,and this allele has become nearly fixed(95%)in northern China.These findings provide a theoretical basis for better understanding the molecular regulatory mechanism of flowering time in soybean and a target gene that can be used for breeding modern soybean cultivars adapted to different latitudes.展开更多
针对厂房、银行和大型超市等需要人工巡逻的场所,文章设计了一款基于ROS的巡逻机器人自主导航系统。文章将ROS系统部署到基于树莓派硬件开发的巡逻机器人上,对巡逻机器人的环境感知模块、导航模块和监控模块等进行研究设计。该系统使用...针对厂房、银行和大型超市等需要人工巡逻的场所,文章设计了一款基于ROS的巡逻机器人自主导航系统。文章将ROS系统部署到基于树莓派硬件开发的巡逻机器人上,对巡逻机器人的环境感知模块、导航模块和监控模块等进行研究设计。该系统使用同步定位与建图(Simultaneous Localization and Mapping,SLAM)技术,通过激光雷达和里程计实现定位、建图与导航功能。实验结果表明,该系统定位收敛速度快,构建地图精度高,路径规划稳定性好,能替代人类巡逻。展开更多
文摘随着4G网络的普及以及5G建设工作的开展,无线网络规划已经成为4G,5G网络建设中十分重要的一项工作。无线网络规划的合理性会直接影响移动网络的建设规模和用户感知。在无线网络规划工作中,可以利用无线网络规划软件作为辅助工具,从而给出更加合理的设计规划。因此,无线网络规划地理信息相关技术的研究及功能的实现对网络规划具有重要意义。移动网络规划软件从软件操作界面、覆盖类型划分、多种规划方式、数据存储等几个方面进行设计开发,通过Microsoft Visual Studio 2019作为开发工具,C#作为开发编程语言,使用免费、开源的.NET地图控件GMap.NET进行二次开发。文章结合网络规划的具体流程,介绍了开发移动网络规划软件中用到的GMap.NET的相关接口、类型及关键方法。
文摘同步定位与建图(Simultaneous Localization and Mapping, SLAM)是自动驾驶领域的关键技术之一。基于差异化的应用场景、传感器和算法,主流SLAM实现方法分为视觉SLAM、激光SLAM和多传感器SLAM等,其性能的优化方向主要基于传感器性能,算法策略以及估计方法。室内场景下,视觉SLAM方法因视觉传感器的视野范围有限且对光线明暗,性能受限于环境变化。多线激光雷达因价格昂贵,不适宜广泛应用。多传感器融合的方案,因部分视觉传感器采集环境特征信息丰富而存在系统运行的时延问题且融合设计复杂度高。针对以上问题,本文提出了一种基于单线激光雷达,感知算法与全局路径规划算法融合的SLAM与自主导航方案,设计软件与硬件结合的系统框架,所实现的运动系统在室内场景下高速获取环境信息,能够获取良好的建图性能并完成低时延自主导航。首先,本文系统利用IMU对单线激光雷达采集的回波数据做畸变矫正,对激光雷达数据采用Gmapping算法处理,并对各传感器的坐标系关系做精确计算和转换,而后采用Djikstra算法作为全局路径规划算法来实现运动系统的自主导航。最终通过实验,利用ROS系统,NVIDIA-Jetson-Nano,IMU、2D-Lidar等,在实际环境中实现了算法模型与系统构建,室内场景中建图效果良好,机器车在同步定位与建图过程中自主导航,验证了本文方案及系统的可靠性与有效性。
基金supported by the National Natural Science Foundation of China(U22A20473)the National Key Research and Development Program of China(2021YFD1201600)+2 种基金the China Agriculture Research System(CARS-04-PS01)the Agricultural Science and Technology Innovation Program(ASTIP)of Chinese Academy of Agricultural Sciences,Scientific Innovation 2030 Project(2022ZD0401703)the Platform of National Crop Germplasm Resources of China。
文摘Flowering time is important for adaptation of soybean(Glycine max)to different environments.Here,we conducted a genome-wide association study of flowering time using a panel of 1490 cultivated soybean accessions.We identified three strong signals at the qFT02-2 locus(Chr02:12037319–12238569),which were associated with flowering time in three environments:Gongzhuling,Mengcheng,and Nanchang.By analyzing linkage disequilibrium,gene expression patterns,gene annotation,and the diversity of variants,we identified an AP1 homolog as the candidate gene for the qFT02-2 locus,which we named GmAP1d.Only one nonsynonymous polymorphism existed among 1490 soybean accessions at position Chr02:12087053.Accessions carrying the Chr02:12087053-T allele flowered significantly earlier than those carrying the Chr02:12087053-A allele.Thus,we developed a cleaved amplified polymorphic sequence(CAPS)marker for the SNP at Chr02:12087053,which is suitable for marker-assisted breeding of flowering time.Knockout of GmAP1d in the‘Williams 82’background by gene editing promoted flowering under long-day conditions,confirming that GmAP1d is the causal gene for qFT02-2.An analysis of the region surrounding GmAP1d revealed that GmAP1d was artificially selected during the genetic improvement of soybean.Through stepwise selection,the proportion of modern cultivars carrying the Chr02:12087053-T allele has increased,and this allele has become nearly fixed(95%)in northern China.These findings provide a theoretical basis for better understanding the molecular regulatory mechanism of flowering time in soybean and a target gene that can be used for breeding modern soybean cultivars adapted to different latitudes.
文摘针对厂房、银行和大型超市等需要人工巡逻的场所,文章设计了一款基于ROS的巡逻机器人自主导航系统。文章将ROS系统部署到基于树莓派硬件开发的巡逻机器人上,对巡逻机器人的环境感知模块、导航模块和监控模块等进行研究设计。该系统使用同步定位与建图(Simultaneous Localization and Mapping,SLAM)技术,通过激光雷达和里程计实现定位、建图与导航功能。实验结果表明,该系统定位收敛速度快,构建地图精度高,路径规划稳定性好,能替代人类巡逻。
