抽象语义表示(Abstract Meaning Representation,AMR)是一种深层次的句子级语义表示形式,其将句子中的语义信息抽象为由概念结点与关系组成的有向无环图,相比其他较为浅层的语义表示形式如语义角色标注、语义依存分析等,AMR因其出色的...抽象语义表示(Abstract Meaning Representation,AMR)是一种深层次的句子级语义表示形式,其将句子中的语义信息抽象为由概念结点与关系组成的有向无环图,相比其他较为浅层的语义表示形式如语义角色标注、语义依存分析等,AMR因其出色的深层次语义信息捕捉能力,被广泛运用在例如信息抽取、智能问答、对话系统等多种下游任务中。AMR解析过程将自然语言转换成AMR图。虽然AMR图中的大部分概念结点和关系与句子中的词语具有较为明显的对齐关系,但原始的英文AMR语料中并没有给出具体的对齐信息。为了克服对齐信息不足给AMR解析以及AMR在下游任务上的应用造成的阻碍,Li等人[14]提出并标注了具有概念和关系对齐的中文AMR语料库。然而,现有的AMR解析方法并不能很好地在AMR解析的过程中利用和生成对齐信息。因此,该文首次提出了一种可以利用并且生成对齐信息的AMR解析方法,包括了概念预测和关系预测两个阶段。该文提出的方法具有高度的灵活性和可扩展性,实验结果表明,该方法在公开数据集CAMR 2.0和CAMRP 2022盲测集分别取得了77.6(+10.6)和70.7(+8.5)的Align Smatch分数,超过了过去基于序列到序列(Sequence-to-Sequence)模型的方法。该文同时对AMR解析的性能和细粒度指标进行详细的分析,并对存在的改进方向进行了展望。该文的代码和模型参数已经开源到https://github.com/pkunlp-icler/Two-Stage-CAMRP,供复现与参考。展开更多
Natural law is an important concept of the Westem political culture. The author makes a simple investigation into the various definitions of natural law, based on which he comes to the conclusion that natural law is a...Natural law is an important concept of the Westem political culture. The author makes a simple investigation into the various definitions of natural law, based on which he comes to the conclusion that natural law is a key concept of Western political culture; that it is a moral norm of politics as well as a product of rational thinking; and that its meaning has varied over time.展开更多
文摘为快速识别冒犯性评论文本中的用户热点主题,解决传统主题模型在处理评论文本时语义描述不充分、上下文信息丢失和主题连贯性不强,以及K-means聚类算法对K值和初始中心点敏感的问题。使用CoSENT(cosine sentence)模型获取包含冒犯性语言的评论文本的句子级向量特征,对通过统一流形逼近与投影算法即UMAP(uniform manifold approximation and projection)模型降维后的向量矩阵使用基于Canopy+的改进K-means算法进行类簇划分,用(class term frequency-inverse document frequency,c-TF-IDF)识别各主题簇的主题特征,进行主题建模。通过对比冒犯性评论文本数据集以及普通评论数据集的实验验证了方法有效性。结果表明本文方法能够得到更好的主题一致性。
文摘Natural law is an important concept of the Westem political culture. The author makes a simple investigation into the various definitions of natural law, based on which he comes to the conclusion that natural law is a key concept of Western political culture; that it is a moral norm of politics as well as a product of rational thinking; and that its meaning has varied over time.