Recent methods for learning vector space representations of words have succeeded in capturing fine-grained semantic and syntactic regularities using vector arithmetic, but the origin of these regularities has remained opaque. We analyze and make explicit the model properties needed for such regularities to emerge in word vectors. The result is a new global logbilinear regression model that combines the advantages of the two major model families in the literature: global matrix factorization and local context window methods. Our model efficiently leverages statistical information by training only on the nonzero elements in a word-word cooccurrence matrix, rather than on the entire sparse matrix or on individual context windows in a large corpus. The model produces a vector space with meaningful substructure, as evidenced by its performance of 75% on a recent word analogy task. It also outperforms related models on similarity tasks and named entity recognition.
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We analyze skip-gram with negative-sampling (SGNS), a word embedding method introduced by Mikolov et al., and show that it is implicitly factorizing a word-context matrix, whose cells are the pointwise mutual information (PMI) of the respective word and context pairs, shifted by a global constant. We find that another embedding method, NCE, is implicitly factorizing a similar matrix, where each cell is the (shifted) log conditional probability of a word given its context. We show that using a sparse Shifted Positive PMI word-context matrix to represent words improves results on two word similarity tasks and one of two analogy tasks. When dense low-dimensional vectors are preferred, exact factorization with SVD can achieve solutions that are at least as good as SGNS's solutions for word similarity tasks. On analogy questions SGNS remains superior to SVD. We conjecture that this stems from the weighted nature of SGNS's factorization.
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Natural Language Understanding has seen an increasing number of publications in the last few years, especially after robust word embeddings models became prominent, when they proved themselves able to capture and represent semantic relationships from massive amounts of data. Nevertheless, traditional models often fall short in intrinsic issues of linguistics, such as polysemy and homonymy. Any expert system that makes use of natural language in its core, can be affected by a weak semantic representation of text, resulting in inaccurate outcomes based on poor decisions. To mitigate such issues, we propose a novel approach called Most Suitable Sense Annotation (MSSA), that disambiguates and annotates each word by its specific sense, considering the semantic effects of its context. Our approach brings three main contributions to the semantic representation scenario: (i) an unsupervised technique that disambiguates and annotates words by their senses, (ii) a multi-sense embeddings model that can be extended to any traditional word embeddings algorithm, and (iii) a recurrent methodology that allows our models to be re-used and their representations refined. We test our approach on six different benchmarks for the word similarity task, showing that our approach can produce state-of-the-art results and outperforms several more complex state-of-the-art systems.
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The recently introduced continuous Skip-gram model is an efficient method for learning high-quality distributed vector representations that capture a large number of precise syntactic and semantic word relationships. In this paper we present several extensions that improve both the quality of the vectors and the training speed. By subsampling of the frequent words we obtain significant speedup and also learn more regular word representations. We also describe a simple alternative to the hierarchical softmax called negative sampling. An inherent limitation of word representations is their indifference to word order and their inability to represent idiomatic phrases. For example, the meanings of "Canada" and "Air" cannot be easily combined to obtain "Air Canada". Motivated by this example, we present a simple method for finding phrases in text, and show that learning good vector representations for millions of phrases is possible.
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Continuous word representations, trained on large unlabeled corpora are useful for many natural language processing tasks. Popular models that learn such representations ignore the morphology of words, by assigning a distinct vector to each word. This is a limitation, especially for languages with large vocabularies and many rare words. In this paper, we propose a new approach based on the skipgram model, where each word is represented as a bag of character n-grams. A vector representation is associated to each character n-gram; words being represented as the sum of these representations. Our method is fast, allowing to train models on large corpora quickly and allows us to compute word representations for words that did not appear in the training data. We evaluate our word representations on nine different languages, both on word similarity and analogy tasks. By comparing to recently proposed morphological word representations, we show that our vectors achieve state-of-the-art performance on these tasks.
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We propose two novel model architectures for computing continuous vector representations of words from very large data sets. The quality of these representations is measured in a word similarity task, and the results are compared to the previously best performing techniques based on different types of neural networks. We observe large improvements in accuracy at much lower computational cost, i.e. it takes less than a day to learn high quality word vectors from a 1.6 billion words data set. Furthermore, we show that these vectors provide state-of-the-art performance on our test set for measuring syntactic and semantic word similarities.
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使用机器学习算法从未标记的文本中提取知识可能很复杂。文档分类和信息检索是两个应用程序,可以从无监督的学习(例如文本聚类和主题建模)中受益,包括探索性数据分析。但是,无监督的学习范式提出了可重复性问题。初始化可能会导致可变性,具体取决于机器学习算法。此外,关于群集几何形状,扭曲可能会产生误导。在原因中,异常值和异常的存在可能是决定因素。尽管初始化和异常问题与文本群集和主题建模相关,但作者并未找到对它们的深入分析。这项调查提供了这些亚地区的系统文献综述(2011-2022),并提出了共同的术语,因为类似的程序具有不同的术语。作者描述了研究机会,趋势和开放问题。附录总结了与审查的作品直接或间接相关的文本矢量化,分解和聚类算法的理论背景。
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在NLP社区中有一个正在进行的辩论,无论现代语言模型是否包含语言知识,通过所谓的探针恢复。在本文中,我们研究了语言知识是否是现代语言模型良好表现的必要条件,我们称之为\ Texit {重新发现假设}。首先,我们展示了语言模型,这是显着压缩的,但在预先磨普目标上表现良好,以便在语言结构探讨时保持良好的分数。这一结果支持重新发现的假设,并导致我们的论文的第二款贡献:一个信息 - 理论框架,与语言建模目标相关。该框架还提供了测量语言信息对字词预测任务的影响的度量标准。我们通过英语综合和真正的NLP任务加固我们的分析结果。
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The relationship between words in a sentence often tells us more about the underlying semantic content of a document than its actual words, individually. In this work, we propose two novel algorithms, called Flexible Lexical Chain II and Fixed Lexical Chain II. These algorithms combine the semantic relations derived from lexical chains, prior knowledge from lexical databases, and the robustness of the distributional hypothesis in word embeddings as building blocks forming a single system. In short, our approach has three main contributions: (i) a set of techniques that fully integrate word embeddings and lexical chains; (ii) a more robust semantic representation that considers the latent relation between words in a document; and (iii) lightweight word embeddings models that can be extended to any natural language task. We intend to assess the knowledge of pre-trained models to evaluate their robustness in the document classification task. The proposed techniques are tested against seven word embeddings algorithms using five different machine learning classifiers over six scenarios in the document classification task. Our results show the integration between lexical chains and word embeddings representations sustain state-of-the-art results, even against more complex systems.
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本文探讨了基于随机索引(RI)的新型变体,用于编码语言数据,以便在动态场景中使用它们以连续方式发生事件。随着Onehot编码的一般方法中的表示的大小随着词汇量的大小而导致的,它们对于具有高卷的动态数据的在线目的变得不可扩展。另一方面,由于文本数据的动态性质,现有的预先训练的嵌入模型不适合检测新事件的发生事件。本工作通过利用新的RI表示来解决这个问题,通过对一类RI表示的随机条目的数量施加概率分布来解决概率分布。它还规则分析了在正交性概率方面编码语义信息的代表方法的良好分析。构建这些想法我们提出了一种算法,该算法与词汇表的大小,以跟踪查询字的语义关系,以便建议与有问题的单词相关的事件。使用特定于三个不同事件的推文数据的所提出的算法,我们耗尽了模拟,并呈现了我们的研究结果。发现所提出的概率RI表示比单词(弓)嵌入的袋子更快,可伸缩,同时保持描绘语义关系的准确性。
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手套通过利用来自Word Co-Feationence矩阵的统计信息来学习Word Embeddings。然而,矩阵中的字对对从预定义的本地上下文窗口中提取,这可能导致有限的字对对和潜在的语义无关词对。在本文中,我们提出了Semglove,其中从伯爵蒸馏到静态手套单词嵌入。特别是,我们提出了两种模型来提取基于屏蔽语言模型或伯特的多针注意重量的共发生统计。我们的方法可以在不受本地窗口假设的情况下提取字对对,并且可以通过直接考虑词对之间的语义距离来定义共发生权重。几个单词相似性数据集和四个外部任务的实验表明semglove可以优于手套。
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Deep Learning and Machine Learning based models have become extremely popular in text processing and information retrieval. However, the non-linear structures present inside the networks make these models largely inscrutable. A significant body of research has focused on increasing the transparency of these models. This article provides a broad overview of research on the explainability and interpretability of natural language processing and information retrieval methods. More specifically, we survey approaches that have been applied to explain word embeddings, sequence modeling, attention modules, transformers, BERT, and document ranking. The concluding section suggests some possible directions for future research on this topic.
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建模法检索和检索作为预测问题最近被出现为法律智能的主要方法。专注于法律文章检索任务,我们展示了一个名为Lamberta的深度学习框架,该框架被设计用于民法代码,并在意大利民法典上专门培训。为了我们的知识,这是第一项研究提出了基于伯特(来自变压器的双向编码器表示)学习框架的意大利法律制度对意大利法律制度的高级法律文章预测的研究,最近引起了深度学习方法的增加,呈现出色的有效性在几种自然语言处理和学习任务中。我们通过微调意大利文章或其部分的意大利预先训练的意大利预先训练的伯爵来定义Lamberta模型,因为法律文章作为分类任务检索。我们Lamberta框架的一个关键方面是我们构思它以解决极端的分类方案,其特征在于课程数量大,少量学习问题,以及意大利法律预测任务的缺乏测试查询基准。为了解决这些问题,我们为法律文章的无监督标签定义了不同的方法,原则上可以应用于任何法律制度。我们提供了深入了解我们Lamberta模型的解释性和可解释性,并且我们对单一标签以及多标签评估任务进行了广泛的查询模板实验分析。经验证据表明了Lamberta的有效性,以及对广泛使用的深度学习文本分类器和一些构思的几次学习者来说,其优越性是对属性感知预测任务的优势。
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基于变压器的语言模型最近在许多自然语言任务中取得了显着的结果。但是,通常通过利用大量培训数据来实现排行榜的性能,并且很少通过将明确的语言知识编码为神经模型。这使许多人质疑语言学对现代自然语言处理的相关性。在本文中,我介绍了几个案例研究,以说明理论语言学和神经语言模型仍然相互关联。首先,语言模型通过提供一个客观的工具来测量语义距离,这对语言学家很有用,语义距离很难使用传统方法。另一方面,语言理论通过提供框架和数据源来探究我们的语言模型,以了解语言理解的特定方面,从而有助于语言建模研究。本论文贡献了三项研究,探讨了语言模型中语法 - 听觉界面的不同方面。在论文的第一部分中,我将语言模型应用于单词类灵活性的问题。我将Mbert作为语义距离测量的来源,我提供了有利于将单词类灵活性分析为方向过程的证据。在论文的第二部分中,我提出了一种方法来测量语言模型中间层的惊奇方法。我的实验表明,包含形态句法异常的句子触发了语言模型早期的惊喜,而不是语义和常识异常。最后,在论文的第三部分中,我适应了一些心理语言学研究,以表明语言模型包含了论证结构结构的知识。总而言之,我的论文在自然语言处理,语言理论和心理语言学之间建立了新的联系,以为语言模型的解释提供新的观点。
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We propose a unified neural network architecture and learning algorithm that can be applied to various natural language processing tasks including: part-of-speech tagging, chunking, named entity recognition, and semantic role labeling. This versatility is achieved by trying to avoid task-specific engineering and therefore disregarding a lot of prior knowledge. Instead of exploiting man-made input features carefully optimized for each task, our system learns internal representations on the basis of vast amounts of mostly unlabeled training data. This work is then used as a basis for building a freely available tagging system with good performance and minimal computational requirements.
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The rapid advancement of AI technology has made text generation tools like GPT-3 and ChatGPT increasingly accessible, scalable, and effective. This can pose serious threat to the credibility of various forms of media if these technologies are used for plagiarism, including scientific literature and news sources. Despite the development of automated methods for paraphrase identification, detecting this type of plagiarism remains a challenge due to the disparate nature of the datasets on which these methods are trained. In this study, we review traditional and current approaches to paraphrase identification and propose a refined typology of paraphrases. We also investigate how this typology is represented in popular datasets and how under-representation of certain types of paraphrases impacts detection capabilities. Finally, we outline new directions for future research and datasets in the pursuit of more effective paraphrase detection using AI.
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最近有一项激烈的活动在嵌入非常高维和非线性数据结构的嵌入中,其中大部分在数据科学和机器学习文献中。我们分四部分调查这项活动。在第一部分中,我们涵盖了非线性方法,例如主曲线,多维缩放,局部线性方法,ISOMAP,基于图形的方法和扩散映射,基于内核的方法和随机投影。第二部分与拓扑嵌入方法有关,特别是将拓扑特性映射到持久图和映射器算法中。具有巨大增长的另一种类型的数据集是非常高维网络数据。第三部分中考虑的任务是如何将此类数据嵌入中等维度的向量空间中,以使数据适合传统技术,例如群集和分类技术。可以说,这是算法机器学习方法与统计建模(所谓的随机块建模)之间的对比度。在论文中,我们讨论了两种方法的利弊。调查的最后一部分涉及嵌入$ \ mathbb {r}^ 2 $,即可视化中。提出了三种方法:基于第一部分,第二和第三部分中的方法,$ t $ -sne,UMAP和大节。在两个模拟数据集上进行了说明和比较。一个由嘈杂的ranunculoid曲线组成的三胞胎,另一个由随机块模型和两种类型的节点产生的复杂性的网络组成。
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该研究解决了在用线性鉴别学习建模拐点形态时出现的一系列方法问题。以半成本德国名词系统为例,我们说明了如何对表单和意义的代表作出的决策如何影响模型性能。我们澄清,为了建模频率效应在学习中,必须利用增量学习而不是学习的肠胃。我们还讨论如何设置模型,以近似语境中的流动词的学习。此外,我们说明了如何在这种方法中如何以相当大的细节建模。通常,该模型为已知的单词提供了优异的存储器,但适当地对未经展示数据进行了更有限的性能,符合德国原住民的德国名词拐点和泛化性能的半生产力。
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Unsupervised vector-based approaches to semantics can model rich lexical meanings, but they largely fail to capture sentiment information that is central to many word meanings and important for a wide range of NLP tasks. We present a model that uses a mix of unsupervised and supervised techniques to learn word vectors capturing semantic term-document information as well as rich sentiment content. The proposed model can leverage both continuous and multi-dimensional sentiment information as well as non-sentiment annotations. We instantiate the model to utilize the document-level sentiment polarity annotations present in many online documents (e.g. star ratings). We evaluate the model using small, widely used sentiment and subjectivity corpora and find it out-performs several previously introduced methods for sentiment classification. We also introduce a large dataset of movie reviews to serve as a more robust benchmark for work in this area.
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随着越来越多的可用文本数据,能够自动分析,分类和摘要这些数据的算法的开发已成为必需品。在本研究中,我们提出了一种用于关键字识别的新颖算法,即表示给定文档的关键方面的一个或多字短语的提取,称为基于变压器的神经标记器,用于关键字识别(TNT-KID)。通过将变压器架构适用于手头的特定任务并利用域特定语料库上的预先磨损的语言模型,该模型能够通过提供竞争和强大的方式克服监督和无监督的最先进方法的缺陷在各种不同的数据集中的性能,同时仅需要最佳执行系统所需的手动标记的数据。本研究还提供了彻底的错误分析,具有对模型内部运作的有价值的见解和一种消融研究,测量关键字识别工作流程的特定组分对整体性能的影响。
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