单脉冲搜索作为脉冲星探测的有力工具,在探测旋转射电暂现源以及快速射电暴中扮演着重要角色。为了从海量的射电巡天数据中快速筛选出最有价值的单脉冲搜索候选体,候选体识别已经从早期启发式阈值判断发展到基于机器学习自动识别。对于F...单脉冲搜索作为脉冲星探测的有力工具,在探测旋转射电暂现源以及快速射电暴中扮演着重要角色。为了从海量的射电巡天数据中快速筛选出最有价值的单脉冲搜索候选体,候选体识别已经从早期启发式阈值判断发展到基于机器学习自动识别。对于FAST观测,研究了基于机器学习的单脉冲搜索候选体识别应用到CRAFTS(the commensal radio astronomy FAST survey)超宽带脉冲星数据的性能表现。在评估过程中,使用单脉冲事件组识别(SPEGID)和单脉冲搜索器(SPS)两类自动识别方法,通过7种不同机器学习分类器对CRAFTS基准数据集产生的单脉冲搜索候选体进行自动识别;作为对比,也使用了启发式阈值判断的方法(RRATtrap和Clusterrank)。结果表明,SPEGID具有最好的性能表现(最高的F1-score值95.1%、次高的召回率95.4%、最低的假阳性率4.7%),SPS具有最快的筛选速度(平均每小时筛选4010个候选体)。通过对比分析结果,探讨了如何基于FAST观测数据开展高效的单脉冲搜索候选体识别。展开更多
对大规模射电天文巡天项目产生的数据进行单脉冲搜索会产生数以亿计的脉冲星候选体。处理了500 m口径球面射电望远镜(Five-hundred-meter Aperture Spherical radio Telescope,FAST)多科学目标同时扫描巡天(The Commensal Radio Astrono...对大规模射电天文巡天项目产生的数据进行单脉冲搜索会产生数以亿计的脉冲星候选体。处理了500 m口径球面射电望远镜(Five-hundred-meter Aperture Spherical radio Telescope,FAST)多科学目标同时扫描巡天(The Commensal Radio Astronomy FAST Survey,CRAFTS)32万个超宽带数据文件,得到5万个脉冲星候选体。针对CRAFTS单脉冲搜索试验结果中脉冲星候选体仅有1.5%真正是脉冲星信号的问题,提出3个显著区分脉冲星信号和干扰的特征,并应用于单脉冲筛选流程。试验结果表明,改进后的单脉冲筛选工具将需要人工检查脉冲星候选体的数量降低了20%,一定程度上提高了CRAFTS巡天数据的单脉冲搜索效率。展开更多
On September 17,the Craftsmanship:Chinese Traditional Arts and Crafts Exhibition,jointly sponsored by China Cultural Center in Tanzania,Network of International Culturalink Entities and Quanzhou Art Museum was open to...On September 17,the Craftsmanship:Chinese Traditional Arts and Crafts Exhibition,jointly sponsored by China Cultural Center in Tanzania,Network of International Culturalink Entities and Quanzhou Art Museum was open to the public in China Cultural Center in Tanzania.展开更多
The China National Arts & Crafts Corporation, subordinate to the China Council of Light Industry, was established with approval from the State Economic and Trade Commission and the Ministry of Foreign Trade and Ec...The China National Arts & Crafts Corporation, subordinate to the China Council of Light Industry, was established with approval from the State Economic and Trade Commission and the Ministry of Foreign Trade and Economic Cooperation.As an export-oriented economic entity, the corporation deals mainly in the import and export of products and raw materials,organizing the production, development展开更多
The Beijing Arts and Crafts Factory is a large comprehensive enterprise under the direction of the Beijing Arts and Handicrafts Group. It has over 2,000 employees and has an international reputation. Since it became a...The Beijing Arts and Crafts Factory is a large comprehensive enterprise under the direction of the Beijing Arts and Handicrafts Group. It has over 2,000 employees and has an international reputation. Since it became an open enterprise, it has visited by many VIPS from foreign countries.展开更多
The China National Arts & Crafts Import & Export Corporation is a large professional foreign trade company under the Ministry of Foreign Economic Relations and Trade. It has made contributions to the export of...The China National Arts & Crafts Import & Export Corporation is a large professional foreign trade company under the Ministry of Foreign Economic Relations and Trade. It has made contributions to the export of China’s arts and crafts. With the deepening of the reform of the foreign trade system, the corporation has been transformed from an executive institution into a commercial enterprise and展开更多
文摘单脉冲搜索作为脉冲星探测的有力工具,在探测旋转射电暂现源以及快速射电暴中扮演着重要角色。为了从海量的射电巡天数据中快速筛选出最有价值的单脉冲搜索候选体,候选体识别已经从早期启发式阈值判断发展到基于机器学习自动识别。对于FAST观测,研究了基于机器学习的单脉冲搜索候选体识别应用到CRAFTS(the commensal radio astronomy FAST survey)超宽带脉冲星数据的性能表现。在评估过程中,使用单脉冲事件组识别(SPEGID)和单脉冲搜索器(SPS)两类自动识别方法,通过7种不同机器学习分类器对CRAFTS基准数据集产生的单脉冲搜索候选体进行自动识别;作为对比,也使用了启发式阈值判断的方法(RRATtrap和Clusterrank)。结果表明,SPEGID具有最好的性能表现(最高的F1-score值95.1%、次高的召回率95.4%、最低的假阳性率4.7%),SPS具有最快的筛选速度(平均每小时筛选4010个候选体)。通过对比分析结果,探讨了如何基于FAST观测数据开展高效的单脉冲搜索候选体识别。
文摘对大规模射电天文巡天项目产生的数据进行单脉冲搜索会产生数以亿计的脉冲星候选体。处理了500 m口径球面射电望远镜(Five-hundred-meter Aperture Spherical radio Telescope,FAST)多科学目标同时扫描巡天(The Commensal Radio Astronomy FAST Survey,CRAFTS)32万个超宽带数据文件,得到5万个脉冲星候选体。针对CRAFTS单脉冲搜索试验结果中脉冲星候选体仅有1.5%真正是脉冲星信号的问题,提出3个显著区分脉冲星信号和干扰的特征,并应用于单脉冲筛选流程。试验结果表明,改进后的单脉冲筛选工具将需要人工检查脉冲星候选体的数量降低了20%,一定程度上提高了CRAFTS巡天数据的单脉冲搜索效率。
文摘On September 17,the Craftsmanship:Chinese Traditional Arts and Crafts Exhibition,jointly sponsored by China Cultural Center in Tanzania,Network of International Culturalink Entities and Quanzhou Art Museum was open to the public in China Cultural Center in Tanzania.
文摘The China National Arts & Crafts Corporation, subordinate to the China Council of Light Industry, was established with approval from the State Economic and Trade Commission and the Ministry of Foreign Trade and Economic Cooperation.As an export-oriented economic entity, the corporation deals mainly in the import and export of products and raw materials,organizing the production, development
文摘The Beijing Arts and Crafts Factory is a large comprehensive enterprise under the direction of the Beijing Arts and Handicrafts Group. It has over 2,000 employees and has an international reputation. Since it became an open enterprise, it has visited by many VIPS from foreign countries.
文摘The China National Arts & Crafts Import & Export Corporation is a large professional foreign trade company under the Ministry of Foreign Economic Relations and Trade. It has made contributions to the export of China’s arts and crafts. With the deepening of the reform of the foreign trade system, the corporation has been transformed from an executive institution into a commercial enterprise and
