Dual-frequency multi-constellation(DFMC) satellitebased augmentation system(SBAS) does not broadcast fast correction, which is important in reducing range error in L1-only SBAS.Meanwhile, the integrity bound of a sate...Dual-frequency multi-constellation(DFMC) satellitebased augmentation system(SBAS) does not broadcast fast correction, which is important in reducing range error in L1-only SBAS.Meanwhile, the integrity bound of a satellite at low elevation is so loose that the service availability is decreased near the boundary of the service area. Therefore, the computation of satellite clockephemeris(SCE) augmentation parameters needs improvement.We propose a method introducing SCE prediction to eliminate most of the SCE error resulting from global navigation satellite system GNSS broadcast message. Compared with the signal-inspace(SIS) after applying augmentation parameters broadcast by the wide area augmentation system(WAAS), SIS accuracy after applying augmentation parameters computed by the proposed algorithm is improved and SIS integrity is ensured. With global positioning system(GPS) only, the availability of category-I(CAT-I)with a vertical alert level of 15 m in continental United States is about 90%, while the availability in the other part of the WAAS service area is markedly improved. With measurements made by the stations from the crustal movement observation network of China,users in some part of China can obtain CAT-I(vertical alert limit is 15 m) service with GPS and global navigation satellite system(GLONASS).展开更多
大语言模型(LLMs,Large Language Models)具有极强的自然语言理解和复杂问题求解能力,本文基于大语言模型构建了矿物问答系统,以高效地获取矿物知识。该系统首先从互联网资源获取矿物数据,清洗后将矿物数据结构化为矿物文档和问答对;将...大语言模型(LLMs,Large Language Models)具有极强的自然语言理解和复杂问题求解能力,本文基于大语言模型构建了矿物问答系统,以高效地获取矿物知识。该系统首先从互联网资源获取矿物数据,清洗后将矿物数据结构化为矿物文档和问答对;将矿物文档经过格式转换和建立索引后转化为矿物知识库,用于检索增强大语言模型生成,问答对用于微调大语言模型。使用矿物知识库检索增强大语言模型生成时,采用先召回再精排的两级检索模式,以获得更好的大语言模型生成结果。矿物大语言模型微调采用了主流的低秩适配(Low-Rank Adaption,LoRA)方法,以较少的训练参数获得了与全参微调性能相当的效果,节省了计算资源。实验结果表明,基于检索增强生成的大语言模型的矿物问答系统能以较高的准确率快捷地获取矿物知识。展开更多
文摘Dual-frequency multi-constellation(DFMC) satellitebased augmentation system(SBAS) does not broadcast fast correction, which is important in reducing range error in L1-only SBAS.Meanwhile, the integrity bound of a satellite at low elevation is so loose that the service availability is decreased near the boundary of the service area. Therefore, the computation of satellite clockephemeris(SCE) augmentation parameters needs improvement.We propose a method introducing SCE prediction to eliminate most of the SCE error resulting from global navigation satellite system GNSS broadcast message. Compared with the signal-inspace(SIS) after applying augmentation parameters broadcast by the wide area augmentation system(WAAS), SIS accuracy after applying augmentation parameters computed by the proposed algorithm is improved and SIS integrity is ensured. With global positioning system(GPS) only, the availability of category-I(CAT-I)with a vertical alert level of 15 m in continental United States is about 90%, while the availability in the other part of the WAAS service area is markedly improved. With measurements made by the stations from the crustal movement observation network of China,users in some part of China can obtain CAT-I(vertical alert limit is 15 m) service with GPS and global navigation satellite system(GLONASS).
文摘大语言模型(LLMs,Large Language Models)具有极强的自然语言理解和复杂问题求解能力,本文基于大语言模型构建了矿物问答系统,以高效地获取矿物知识。该系统首先从互联网资源获取矿物数据,清洗后将矿物数据结构化为矿物文档和问答对;将矿物文档经过格式转换和建立索引后转化为矿物知识库,用于检索增强大语言模型生成,问答对用于微调大语言模型。使用矿物知识库检索增强大语言模型生成时,采用先召回再精排的两级检索模式,以获得更好的大语言模型生成结果。矿物大语言模型微调采用了主流的低秩适配(Low-Rank Adaption,LoRA)方法,以较少的训练参数获得了与全参微调性能相当的效果,节省了计算资源。实验结果表明,基于检索增强生成的大语言模型的矿物问答系统能以较高的准确率快捷地获取矿物知识。
