In a citation graph, adjacent paper nodes share related scientific terms and topics. The graph thus conveys unique structure information of document-level relatedness that can be utilized in the paper summarization task, for exploring beyond the intra-document information. In this work, we focus on leveraging citation graphs to improve scientific paper extractive summarization under different settings. We first propose a Multi-granularity Unsupervised Summarization model (MUS) as a simple and low-cost solution to the task. MUS finetunes a pre-trained encoder model on the citation graph by link prediction tasks. Then, the abstract sentences are extracted from the corresponding paper considering multi-granularity information. Preliminary results demonstrate that citation graph is helpful even in a simple unsupervised framework. Motivated by this, we next propose a Graph-based Supervised Summarization model (GSS) to achieve more accurate results on the task when large-scale labeled data are available. Apart from employing the link prediction as an auxiliary task, GSS introduces a gated sentence encoder and a graph information fusion module to take advantage of the graph information to polish the sentence representation. Experiments on a public benchmark dataset show that MUS and GSS bring substantial improvements over the prior state-of-the-art model.

Nowadays, time-stamped web documents related to a general news query floods spread throughout the Internet, and timeline summarization targets concisely summarizing the evolution trajectory of events along the timeline. Unlike traditional document summarization, timeline summarization needs to model the time series information of the input events and summarize important events in chronological order. To tackle this challenge, in this paper, we propose a Unified Timeline Summarizer (UTS) that can generate abstractive and extractive timeline summaries in time order. Concretely, in the encoder part, we propose a graph-based event encoder that relates multiple events according to their content dependency and learns a global representation of each event. In the decoder part, to ensure the chronological order of the abstractive summary, we propose to extract the feature of event-level attention in its generation process with sequential information remained and use it to simulate the evolutionary attention of the ground truth summary. The event-level attention can also be used to assist in extracting summary, where the extracted summary also comes in time sequence. We augment the previous Chinese large-scale timeline summarization dataset and collect a new English timeline dataset. Extensive experiments conducted on these datasets and on the out-of-domain Timeline 17 dataset show that UTS achieves state-of-the-art performance in terms of both automatic and human evaluations.

多文件科学摘要（MDSS）旨在为与主题相关的科学论文群生成连贯和简洁的摘要。此任务需要精确理解纸张内容以及对交叉纸关系的准确建模。知识图为文档传达了紧凑且可解释的结构化信息，这使其非常适合内容建模和关系建模。在本文中，我们提出了KGSUM，这是一个MDSS模型，以编码和解码过程中的知识图为中心。具体而言，在编码过程中，提出了两个基于图的模块，以将知识图信息纳入纸张编码，而在解码过程中，我们通过以描述性句子的形式首先生成摘要的知识图，提出了一个两阶段解码器。 ，然后生成最终摘要。经验结果表明，所提出的体系结构对多XSCIENCE数据集的基准进行了实质性改进。

Though many algorithms can be used to automatically summarize legal case decisions, most fail to incorporate domain knowledge about how important sentences in a legal decision relate to a representation of its document structure. For example, analysis of a legal case summarization dataset demonstrates that sentences serving different types of argumentative roles in the decision appear in different sections of the document. In this work, we propose an unsupervised graph-based ranking model that uses a reweighting algorithm to exploit properties of the document structure of legal case decisions. We also explore the impact of using different methods to compute the document structure. Results on the Canadian Legal Case Law dataset show that our proposed method outperforms several strong baselines.

诸如学术文章和商业报告之类的长期文件一直是详细说明重要问题和需要额外关注的复杂主题的标准格式。自动汇总系统可以有效地将长文档置于简短而简洁的文本中，以封装最重要的信息，从而在帮助读者的理解中很重要。最近，随着神经体系结构的出现，已经做出了重大的研究工作，以推动自动文本摘要系统，以及有关将这些系统扩展到长期文档领域的挑战的大量研究。在这项调查中，我们提供了有关长期文档摘要的研究的全面概述，以及其研究环境的三个主要组成部分的系统评估：基准数据集，汇总模型和评估指标。对于每个组成部分，我们在长期汇总的背景下组织文献，并进行经验分析，以扩大有关当前研究进度的观点。实证分析包括一项研究基准数据集的内在特征，摘要模型的多维分析以及摘要评估指标的综述。根据总体发现，我们通过提出可能在这个快速增长的领域中提出未来探索的方向来得出结论。

多文件摘要（MDS）是信息聚合的有效工具，它从与主题相关文档集群生成信息和简洁的摘要。我们的调查是，首先，系统地概述了最近的基于深度学习的MDS模型。我们提出了一种新的分类学，总结神经网络的设计策略，并进行全面的最先进的概要。我们突出了在现有文献中很少讨论的各种客观函数之间的差异。最后，我们提出了与这个新的和令人兴奋的领域有关的几个方向。

学术研究是解决以前从未解决过的问题的探索活动。通过这种性质，每个学术研究工作都需要进行文献审查，以区分其Novelties尚未通过事先作品解决。在自然语言处理中，该文献综述通常在“相关工作”部分下进行。鉴于研究文件的其余部分和引用的论文列表，自动相关工作生成的任务旨在自动生成“相关工作”部分。虽然这项任务是在10年前提出的，但直到最近，它被认为是作为科学多文件摘要问题的变种。然而，即使在今天，尚未标准化了自动相关工作和引用文本生成的问题。在这项调查中，我们进行了一个元研究，从问题制定，数据集收集，方法方法，绩效评估和未来前景的角度来比较相关工作的现有文献，以便为读者洞察到国家的进步 - 最内容的研究，以及如何进行未来的研究。我们还调查了我们建议未来工作要考虑整合的相关研究领域。

无监督的摘要方法通过纳入预训练的语言模型的表示形式来取得了显着的结果。但是，当输入文档非常长的同时，现有方法无法考虑效率和有效性。为了解决这个问题，在本文中，我们提出了一个基于语义块的无监督长期文档摘要，提议有效的粗到1个方面的排名（C2F-FAR）框架。语义块是指描述相同方面的文档中的连续句子。具体而言，我们通过将一步排名方法转换为层次多范围两阶段排名来解决此问题。在粗级阶段，我们提出了一种新的段算法，将文档拆分为相关的语义块，然后过滤量微不足道的块。在精细阶段，我们在每个块中选择显着句子，然后从选定的句子中提取最终摘要。我们在四个长文档摘要数据集上评估了我们的框架：Gov-Report，Billsum，Arxiv和PubMed。我们的C2F-FAR可以在Gov-Report和Billsum上实现新的无监督摘要结果。此外，我们的方法比以前的方法高4-28倍。

Text summarization is a user-preference based task, i.e., for one document, users often have different priorities for summary. As a key aspect of customization in summarization, granularity is used to measure the semantic coverage between the summary and source document. However, developing systems that can generate summaries with customizable semantic coverage is still an under-explored topic. In this paper, we propose the first unsupervised multi-granularity summarization framework, GranuSum. We take events as the basic semantic units of the source documents and propose to rank these events by their salience. We also develop a model to summarize input documents with given events as anchors and hints. By inputting different numbers of events, GranuSum is capable of producing multi-granular summaries in an unsupervised manner. Meanwhile, we annotate a new benchmark GranuDUC that contains multiple summaries at different granularities for each document cluster. Experimental results confirm the substantial superiority of GranuSum on multi-granularity summarization over strong baselines. Further, by exploiting the event information, GranuSum also exhibits state-of-the-art performance under the conventional unsupervised abstractive setting. Dataset for this paper can be found at: https://github.com/maszhongming/GranuDUC

In the scenario of unsupervised extractive summarization, learning high-quality sentence representations is essential to select salient sentences from the input document. Previous studies focus more on employing statistical approaches or pre-trained language models (PLMs) to extract sentence embeddings, while ignoring the rich information inherent in the heterogeneous types of interaction between words and sentences. In this paper, we are the first to propose an unsupervised extractive summarizaiton method with heterogeneous graph embeddings (HGEs) for Chinese document. A heterogeneous text graph is constructed to capture different granularities of interactions by incorporating graph structural information. Moreover, our proposed graph is general and flexible where additional nodes such as keywords can be easily integrated. Experimental results demonstrate that our method consistently outperforms the strong baseline in three summarization datasets.

Bidirectional Encoder Representations from Transformers (BERT; Devlin et al. 2019) represents the latest incarnation of pretrained language models which have recently advanced a wide range of natural language processing tasks. In this paper, we showcase how BERT can be usefully applied in text summarization and propose a general framework for both extractive and abstractive models. We introduce a novel document-level encoder based on BERT which is able to express the semantics of a document and obtain representations for its sentences. Our extractive model is built on top of this encoder by stacking several intersentence Transformer layers. For abstractive summarization, we propose a new fine-tuning schedule which adopts different optimizers for the encoder and the decoder as a means of alleviating the mismatch between the two (the former is pretrained while the latter is not). We also demonstrate that a two-staged fine-tuning approach can further boost the quality of the generated summaries. Experiments on three datasets show that our model achieves stateof-the-art results across the board in both extractive and abstractive settings. 1

对比学习模型在无监督的视觉表示学习中取得了巨大成功，这使得相同图像的不同视图的特征表示之间的相似性最大化，同时最小化不同图像的视图的特征表示之间的相似性。在文本摘要中，输出摘要是输入文档的较短形式，它们具有类似的含义。在本文中，我们提出了对监督抽象文本摘要的对比学习模型，在那里我们查看文档，它的金摘要及其模型生成的摘要，与相同的平均表示的不同视图，并在培训期间最大化它们之间的相似性。我们在三个不同的摘要数据集上改进了一个强序列到序列文本生成模型（即，BART）。人类评估还表明，与其对应物相比，我们的模型达到了更好的忠实性评级，没有对比的目标。

尽管最近的抽象摘要有所改善，但大多数当前方法都会产生与源文档不一致的摘要，从而严重限制了其在现实世界应用中的信任和使用。最近的作品显示了使用文本或依赖性弧形识别事实错误识别的有希望的改进；但是，他们不会同时考虑整个语义图。为此，我们提出了Factgraph，该方法将文档分解为结构化含义表示（MR），更适合于事实评估。太太描述了核心语义概念及其关系，以规范形式汇总文档和摘要中的主要内容，并减少数据稀疏性。 Factgraph使用与结构感知适配器增强的图形编码器编码此类图，以根据图形连接性捕获概念之间的交互，以及使用基于适配器的文本编码器的文本表示。在不同基准上进行评估事实的实验表明，事实图的表现优于先前的方法高达15％。此外，Factgraph改善了识别内容可验证性错误的性能，并更好地捕获了附近级别的事实不一致。

Machine reading comprehension (MRC) is a long-standing topic in natural language processing (NLP). The MRC task aims to answer a question based on the given context. Recently studies focus on multi-hop MRC which is a more challenging extension of MRC, which to answer a question some disjoint pieces of information across the context are required. Due to the complexity and importance of multi-hop MRC, a large number of studies have been focused on this topic in recent years, therefore, it is necessary and worth reviewing the related literature. This study aims to investigate recent advances in the multi-hop MRC approaches based on 31 studies from 2018 to 2022. In this regard, first, the multi-hop MRC problem definition will be introduced, then 31 models will be reviewed in detail with a strong focus on their multi-hop aspects. They also will be categorized based on their main techniques. Finally, a fine-grain comprehensive comparison of the models and techniques will be presented.

最近，神经主题模型（NTMS）已纳入预训练的语言模型（PLM）中，以捕获用于文本摘要的全局语义信息。但是，在这些方法中，它们捕获和整合全局语义信息的方式仍然存在局限性。在本文中，我们提出了一个新颖的模型，即图形对比主题增强语言模型（GRETEL），该模型将图形对比主题模型与预训练的语言模型结合在一起，以充分利用长文档提取的全球和本地上下文语义摘要。为了更好地捕获并将全局语义信息纳入PLM，图形对比主题模型集成了层次变压器编码器和图形对比度学习，以从全局文档上下文和金摘要中融合语义信息。为此，Gretel鼓励该模型有效提取与黄金摘要有关的显着句子，而不是涵盖亚最佳主题的多余句子。对通用域和生物医学数据集的实验结果表明，我们所提出的方法优于SOTA方法。

现有摘要系统主要生成纯粹依赖源文档内容的摘要。但是，即使对于人类，我们通常需要一些引用或示例，帮助我们充分了解源文档并以特定格式写入摘要。但是如何找到高质量的样式，并将它们纳入总结系统仍然挑战和探索。在本文中，我们提出了一种由致密的猎犬和摘要提升的新型检索增强的抽象概要框架。首先，检索几个密切相关的示例作为补充输入，以帮助生成模型更全面地了解文本。此外，检索的示例也可以在引导模型以捕获特定语料库的写入风格中起作用。我们在多个域和两个骨干型号的各种摘要数据集上验证我们的方法：BERT和BART。结果表明，与强大的预训练模型相比，我们的框架在胭脂-1分数中获得了1.38〜4.66的显着改善，并在账单上实现了新的最先进。人类评估表明我们的检索增强模型可以更好地捕获特定于域的书写风格。

本文对过去二十年来对自然语言生成（NLG）的研究提供了全面的审查，特别是与数据到文本生成和文本到文本生成深度学习方法有关，以及NLG的新应用技术。该调查旨在（a）给出关于NLG核心任务的最新综合，以及该领域采用的建筑;（b）详细介绍各种NLG任务和数据集，并提请注意NLG评估中的挑战，专注于不同的评估方法及其关系;（c）强调一些未来的强调和相对近期的研究问题，因为NLG和其他人工智能领域的协同作用而增加，例如计算机视觉，文本和计算创造力。

Modern multi-document summarization (MDS) methods are based on transformer architectures. They generate state of the art summaries, but lack explainability. We focus on graph-based transformer models for MDS as they gained recent popularity. We aim to improve the explainability of the graph-based MDS by analyzing their attention weights. In a graph-based MDS such as GraphSum, vertices represent the textual units, while the edges form some similarity graph over the units. We compare GraphSum's performance utilizing different textual units, i. e., sentences versus paragraphs, on two news benchmark datasets, namely WikiSum and MultiNews. Our experiments show that paragraph-level representations provide the best summarization performance. Thus, we subsequently focus oAnalysisn analyzing the paragraph-level attention weights of GraphSum's multi-heads and decoding layers in order to improve the explainability of a transformer-based MDS model. As a reference metric, we calculate the ROUGE scores between the input paragraphs and each sentence in the generated summary, which indicate source origin information via text similarity. We observe a high correlation between the attention weights and this reference metric, especially on the the later decoding layers of the transformer architecture. Finally, we investigate if the generated summaries follow a pattern of positional bias by extracting which paragraph provided the most information for each generated summary. Our results show that there is a high correlation between the position in the summary and the source origin.

Information overloading requires the need for summarizers to extract salient information from the text. Currently, there is an overload of dialogue data due to the rise of virtual communication platforms. The rise of Covid-19 has led people to rely on online communication platforms like Zoom, Slack, Microsoft Teams, Discord, etc. to conduct their company meetings. Instead of going through the entire meeting transcripts, people can use meeting summarizers to select useful data. Nevertheless, there is a lack of comprehensive surveys in the field of meeting summarizers. In this survey, we aim to cover recent meeting summarization techniques. Our survey offers a general overview of text summarization along with datasets and evaluation metrics for meeting summarization. We also provide the performance of each summarizer on a leaderboard. We conclude our survey with different challenges in this domain and potential research opportunities for future researchers.

对科学论文的海报生成问题受到了调查。海报通常呈现最重要的文件信息，并且任务可以被视为文档摘要的特殊形式。以前的研究主要关注海报布局和面板组成，同时忽略内容提取的重要性。此外，他们的数据集不公开，阻碍了进一步的研究。在本文中，我们从划痕到此任务构造基准数据集。然后，我们提出了一个三步框架来解决这项任务并专注于本研究中的内容提取步骤。为了获得海报面板的两种文本和可视元素，建议同时提取纸张部分的文本，图和表格。我们对数据集进行实验，并进行消融研究。结果证明了我们提出的模型的功效。数据集和代码将被释放。