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基于多任务学习的跨语言信息检索方法研究 被引量:2
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作者 代佳洋 周栋 《广西师范大学学报(自然科学版)》 CAS 北大核心 2022年第6期69-81,共13页
跨语言信息检索是信息检索领域的重要任务之一。现有的跨语言神经检索方法通常使用单任务学习,单一的特征捕捉模式限制了神经检索模型的性能。为此,本文提出一种基于多任务学习的跨语言检索方法,利用文本分类任务作为辅助任务,使用共享... 跨语言信息检索是信息检索领域的重要任务之一。现有的跨语言神经检索方法通常使用单任务学习,单一的特征捕捉模式限制了神经检索模型的性能。为此,本文提出一种基于多任务学习的跨语言检索方法,利用文本分类任务作为辅助任务,使用共享文本特征提取层同时捕捉2个任务的特征信息,使其学习不同任务的特征模式,然后将特征向量分别输入到神经检索模型和文本分类模型中完成2个任务。另外,文本分类任务引入的外部语料也在一定程度上起到了数据增强的作用,进一步增加了特征信息的层次。在CLEF 2000-2003数据集的4个语言对上进行的实验表明,本方法明显改善了文本特征提取的效果,从而增强了神经检索模型性能,使神经检索模型的MAP值提高0.012~0.188,并使模型收敛速度平均提高了24.3%。 展开更多
关键词 信息检索 多任务学习 跨语言信息检索 神经检索模型 外部语料
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China's Global Shipping Connectivity:Internal and External Dynamics in the Contemporary Era(1890–2016) 被引量:6
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作者 Cesar DUCRUET WANG Liehui 《Chinese Geographical Science》 SCIE CSCD 2018年第2期202-216,共15页
China's global shipping connectivity had been somewhat overlooked as the bulk of related studies predominantly focused on the throughput volume of its own port cities. This article tackles such lacunae by providin... China's global shipping connectivity had been somewhat overlooked as the bulk of related studies predominantly focused on the throughput volume of its own port cities. This article tackles such lacunae by providing a relational perspective based on the extraction of vessel movement archives from the Lloyd's List corpus. Two complementary analyses are proposed: long-term dynamics with all ships included(1890–2008) and medium-term dynamics focusing on container flows(1978–2016). Each analysis examines China's maritime connectivity in various ways and on different spatial scales, from the global to the local, in terms of concentration, vulnerability, and expansion. The main results underline the influence of technological, economic, and political factors on the changing distribution of connectivity internally and externally. In particular, China has managed to reduce its dependence upon external transit hubs, to increase the internal connectivity of its own port system, and to strengthen its dominance towards an increasing number of foreign nodes and trade partners through the maritime network. 展开更多
关键词 China CONNECTIVITY maritime network port system vessel movements
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