The size of the Audio and Video(AV)content of the 8K program is four times larger than that of 4K content,providing viewers with a more ideal audiovisual experience while placing higher demands on the capability and e...The size of the Audio and Video(AV)content of the 8K program is four times larger than that of 4K content,providing viewers with a more ideal audiovisual experience while placing higher demands on the capability and efficiency of document preparation and processing,signal transmission,and scheduling.However,it is difficult to meet the high robustness requirements of 8K broadcast services because the existing broadcast system architecture is limited by efficiency,cost,and other factors.In this study,an 8K Ultra-High-Definition(UHD)TV program broadcast scheme was designed.The verification results show that the scheme is high quality,highly efficient,and robust.In particular,in the research,the file format normalizing module was first placed in the broadcast area instead of the file preparation area,and the low-compression transmission scheme of the all-IP signal JPEG XS was designed in the signal transmission area for improving the efficiency of the scheme.Next,to reduce the impact on the robustness of broadcast services,the broadcast control logic of the broadcast core components is optimized.Finally,a series of 8K TV program broadcasting systems have been implemented and their performance has been verified.The results show that the system meets the efficiency and robustness requirements of a high-quality 8K AV broadcast system,and thus has a high degree of practicability.展开更多
城市空间发展易受地形所限,削山造地能克服土地资源稀缺,成为解决城市空间拓展最为直接的途径。该方法利用遥感技术快速准确获取削山造地范围信息,对区域生态环境科学评估和新城发展规划具有十分重要的意义。本文基于GEE遥感云计算平台...城市空间发展易受地形所限,削山造地能克服土地资源稀缺,成为解决城市空间拓展最为直接的途径。该方法利用遥感技术快速准确获取削山造地范围信息,对区域生态环境科学评估和新城发展规划具有十分重要的意义。本文基于GEE遥感云计算平台,利用Sentinel-1合成孔径雷达(synthetic aperture Rader,SAR)数据,采用组合升、降轨影像,在噪声滤除和多时相影像合成的基础上,计算削山造地前后后向散射强度的差值,并采用百分位阈值法结合样本数据确定阈值,提取研究区2017—2022年削山造地开挖区时空分布;然后联合SAR和光学数据的光谱特征、纹理特征和地形特征,在特征优化的基础上结合随机森林算法获取了2017—2022年逐年削山造地范围时空分布。研究结果表明:①提取的开挖区范围总体分类精度和Kappa系数分别达85%和0.83。②研究期间,发现2019年前开挖区主要集中在九州开发区、碧桂园和保利领秀山,2020年以后新增加了刘家沟、水源站等开挖区,开挖范围和强度逐渐增大。③2018年前造地规模较小,面积为2.655 km 2;2019年以后造地规模逐年增大,特别是2021年,其造地面积达12.607 km 2,占监测期间总造地面积的34.56%,2022年在原造地基础上开挖,因坡度和开挖量逐渐增大,造地面积仅2.686 km 2。本文构建的削山造地开挖区监测和造地范围提取方法可有效获取削山和造地范围快速监测与提取。展开更多
面向有人车引导的无人多车编队场景,设计并实现无人车在编队行驶中的车辆识别与轨迹跟踪控制系统,提出了一种多传感器后融合动目标检测算法,使用激光雷达、相机和毫米波雷达3种传感器作为数据源,分别使用欧式聚类、深度学习和运动学推...面向有人车引导的无人多车编队场景,设计并实现无人车在编队行驶中的车辆识别与轨迹跟踪控制系统,提出了一种多传感器后融合动目标检测算法,使用激光雷达、相机和毫米波雷达3种传感器作为数据源,分别使用欧式聚类、深度学习和运动学推理的方法对潜在目标进行检测,进而提出后融合方法将多源检测结果融合以实现对前方车辆的准确检测。基于前车轨迹生成期望路径并设计卡尔曼滤波器对期望路径进行平滑和滤波。构建车辆动力学模型、车辆道路误差模型并设计鲁棒H∞控制器进行车辆轨迹跟踪控制仿真。仿真与实车验证结果表明:在测试路段对前方车辆的平均识别准确率大于95%;实时期望路径相对于真实轨迹的均方差和轨迹平均变化率在滤波前后分别降低17.3%和48.6%;侧向控制位置误差和航向角误差相较于PID(proportional integral derivative)控制分别降低了29%和41%;车辆编队以最高54 km/h的速度实现编队整体的稳定行驶。展开更多
文摘The size of the Audio and Video(AV)content of the 8K program is four times larger than that of 4K content,providing viewers with a more ideal audiovisual experience while placing higher demands on the capability and efficiency of document preparation and processing,signal transmission,and scheduling.However,it is difficult to meet the high robustness requirements of 8K broadcast services because the existing broadcast system architecture is limited by efficiency,cost,and other factors.In this study,an 8K Ultra-High-Definition(UHD)TV program broadcast scheme was designed.The verification results show that the scheme is high quality,highly efficient,and robust.In particular,in the research,the file format normalizing module was first placed in the broadcast area instead of the file preparation area,and the low-compression transmission scheme of the all-IP signal JPEG XS was designed in the signal transmission area for improving the efficiency of the scheme.Next,to reduce the impact on the robustness of broadcast services,the broadcast control logic of the broadcast core components is optimized.Finally,a series of 8K TV program broadcasting systems have been implemented and their performance has been verified.The results show that the system meets the efficiency and robustness requirements of a high-quality 8K AV broadcast system,and thus has a high degree of practicability.
文摘城市空间发展易受地形所限,削山造地能克服土地资源稀缺,成为解决城市空间拓展最为直接的途径。该方法利用遥感技术快速准确获取削山造地范围信息,对区域生态环境科学评估和新城发展规划具有十分重要的意义。本文基于GEE遥感云计算平台,利用Sentinel-1合成孔径雷达(synthetic aperture Rader,SAR)数据,采用组合升、降轨影像,在噪声滤除和多时相影像合成的基础上,计算削山造地前后后向散射强度的差值,并采用百分位阈值法结合样本数据确定阈值,提取研究区2017—2022年削山造地开挖区时空分布;然后联合SAR和光学数据的光谱特征、纹理特征和地形特征,在特征优化的基础上结合随机森林算法获取了2017—2022年逐年削山造地范围时空分布。研究结果表明:①提取的开挖区范围总体分类精度和Kappa系数分别达85%和0.83。②研究期间,发现2019年前开挖区主要集中在九州开发区、碧桂园和保利领秀山,2020年以后新增加了刘家沟、水源站等开挖区,开挖范围和强度逐渐增大。③2018年前造地规模较小,面积为2.655 km 2;2019年以后造地规模逐年增大,特别是2021年,其造地面积达12.607 km 2,占监测期间总造地面积的34.56%,2022年在原造地基础上开挖,因坡度和开挖量逐渐增大,造地面积仅2.686 km 2。本文构建的削山造地开挖区监测和造地范围提取方法可有效获取削山和造地范围快速监测与提取。
文摘面向有人车引导的无人多车编队场景,设计并实现无人车在编队行驶中的车辆识别与轨迹跟踪控制系统,提出了一种多传感器后融合动目标检测算法,使用激光雷达、相机和毫米波雷达3种传感器作为数据源,分别使用欧式聚类、深度学习和运动学推理的方法对潜在目标进行检测,进而提出后融合方法将多源检测结果融合以实现对前方车辆的准确检测。基于前车轨迹生成期望路径并设计卡尔曼滤波器对期望路径进行平滑和滤波。构建车辆动力学模型、车辆道路误差模型并设计鲁棒H∞控制器进行车辆轨迹跟踪控制仿真。仿真与实车验证结果表明:在测试路段对前方车辆的平均识别准确率大于95%;实时期望路径相对于真实轨迹的均方差和轨迹平均变化率在滤波前后分别降低17.3%和48.6%;侧向控制位置误差和航向角误差相较于PID(proportional integral derivative)控制分别降低了29%和41%;车辆编队以最高54 km/h的速度实现编队整体的稳定行驶。
