基于整数最小二乘(integer least squares,ILS)估计的精密单点定位(precise point positioning,PPP)模糊度解算需要进行整数检验,任何漏检和误报均可能导致模糊度固定错误。采用最优整数等变(best integer equivariant,BIE)估计无须进...基于整数最小二乘(integer least squares,ILS)估计的精密单点定位(precise point positioning,PPP)模糊度解算需要进行整数检验,任何漏检和误报均可能导致模糊度固定错误。采用最优整数等变(best integer equivariant,BIE)估计无须进行检验,且其解在所有整数估计类中具有最小均方误差性质。选取全球分布的100个国际全球导航卫星系统服务测站实测数据,分别采取BIE估计、ILS全模糊度固定及部分模糊度固定(partial ambiguity resolution,PAR)解算策略,对不同解算模式下仿动态PPP模糊度固定(PPP with ambiguity resolution,PPP-AR)定位性能进行了对比分析。结果表明,在PPP模糊度估计模型强度相对较弱、收敛精度受限阶段,采用传统ILS算法存在较高AR错误风险,而基于模糊度整数候选解加权融合的BIE最小均方误差解更为稳定,能有效抑制定位解的跳跃。与ILS-PAR解算策略相比,BIE能显著提升PPP-AR收敛速度;在70%与90%分位数下,BIE相较ILS-PAR解算的平面和高程分量收敛时间分别缩短18.8%、13.8%与24.3%、15.9%。在定位精度方面,BIE较ILS-FAR解算结果有明显改善,平面和高程分量精度分别提升43.3%、15.3%(90%分位数),仅略优于ILS-PAR。展开更多
The discourse marker ni hai bie shuo(你还别说)often appears at the beginning of a sentence,connecting to a rich variety of clause types.Its co-occurring words are mostly those expressing subjective evaluation.The subs...The discourse marker ni hai bie shuo(你还别说)often appears at the beginning of a sentence,connecting to a rich variety of clause types.Its co-occurring words are mostly those expressing subjective evaluation.The subsequent discourse it connects to mainly consists of three clause types:explanatory,resultative,and adversative.The basic semantic structure of the segment in which it appears is:(S1)+ni hai bie shuo+S2.It serves seven textual functions,such as the agreement function,negation function,reminding function,and topic-shifting function.展开更多
On July 2,2002, Bureau of International Exhibition’s (BIE) 131st General Assemblywas convened in Paris. The assembly examined the investigation report by BIE InvestigationDelegation for those application countries. V...On July 2,2002, Bureau of International Exhibition’s (BIE) 131st General Assemblywas convened in Paris. The assembly examined the investigation report by BIE InvestigationDelegation for those application countries. Various application countries stated reportsrespectively.The Chinese Government Delegation headed by State Councilor Wu Yi attended the assembly, and stated report on China’s Shanghai making application to hold 2010 World Fair.展开更多
China Pavilion Opens at Expo 2025 Osaka On April 13,2025,the China Pavilion at the Expo 2025 Osaka in Japan was officially opened.The opening ceremony was attended by Chinese and foreign vips,including Ren Hongbin,C...China Pavilion Opens at Expo 2025 Osaka On April 13,2025,the China Pavilion at the Expo 2025 Osaka in Japan was officially opened.The opening ceremony was attended by Chinese and foreign vips,including Ren Hongbin,Chairman of the China Council for the Promotion of International Trade (CCPIT);Alain Berger,President of the Bureau International des Expositions (BIE);Dimitri Kerkentzes,Secretary General of the BIE.展开更多
文摘基于整数最小二乘(integer least squares,ILS)估计的精密单点定位(precise point positioning,PPP)模糊度解算需要进行整数检验,任何漏检和误报均可能导致模糊度固定错误。采用最优整数等变(best integer equivariant,BIE)估计无须进行检验,且其解在所有整数估计类中具有最小均方误差性质。选取全球分布的100个国际全球导航卫星系统服务测站实测数据,分别采取BIE估计、ILS全模糊度固定及部分模糊度固定(partial ambiguity resolution,PAR)解算策略,对不同解算模式下仿动态PPP模糊度固定(PPP with ambiguity resolution,PPP-AR)定位性能进行了对比分析。结果表明,在PPP模糊度估计模型强度相对较弱、收敛精度受限阶段,采用传统ILS算法存在较高AR错误风险,而基于模糊度整数候选解加权融合的BIE最小均方误差解更为稳定,能有效抑制定位解的跳跃。与ILS-PAR解算策略相比,BIE能显著提升PPP-AR收敛速度;在70%与90%分位数下,BIE相较ILS-PAR解算的平面和高程分量收敛时间分别缩短18.8%、13.8%与24.3%、15.9%。在定位精度方面,BIE较ILS-FAR解算结果有明显改善,平面和高程分量精度分别提升43.3%、15.3%(90%分位数),仅略优于ILS-PAR。
文摘The discourse marker ni hai bie shuo(你还别说)often appears at the beginning of a sentence,connecting to a rich variety of clause types.Its co-occurring words are mostly those expressing subjective evaluation.The subsequent discourse it connects to mainly consists of three clause types:explanatory,resultative,and adversative.The basic semantic structure of the segment in which it appears is:(S1)+ni hai bie shuo+S2.It serves seven textual functions,such as the agreement function,negation function,reminding function,and topic-shifting function.
文摘On July 2,2002, Bureau of International Exhibition’s (BIE) 131st General Assemblywas convened in Paris. The assembly examined the investigation report by BIE InvestigationDelegation for those application countries. Various application countries stated reportsrespectively.The Chinese Government Delegation headed by State Councilor Wu Yi attended the assembly, and stated report on China’s Shanghai making application to hold 2010 World Fair.
文摘China Pavilion Opens at Expo 2025 Osaka On April 13,2025,the China Pavilion at the Expo 2025 Osaka in Japan was officially opened.The opening ceremony was attended by Chinese and foreign vips,including Ren Hongbin,Chairman of the China Council for the Promotion of International Trade (CCPIT);Alain Berger,President of the Bureau International des Expositions (BIE);Dimitri Kerkentzes,Secretary General of the BIE.
