测序技术容易出错,对下游应用程序进行纠错(EC)。需要手动配置EC工具以获得最佳性能。我们发现最佳参数(例如,k-mer大小)是依赖于工具和数据集。此外,评估给定工具的性能(即,对准速率或增益)通常依赖于参考基因组,但是质量参考基因组并不总是可用的。我们介绍了基于K-MEC的自动配置的Lerna。 Lerna首先创建未校正的基因组读取的语言模型(LM);然后,计算困惑度量以评估不同参数选择的校正读取。接下来,在不使用参考基因​​组的情况下发现产生最高对准率的那个。我们的方法的基本直觉是困惑度量与纠错后的组件的质量与组件的质量相反。结果:首先,我们表明,即使对于相同的EC工具,不同的数据集也可以对不同的数据集格变化。其次,我们使用其组件基于关注的变压器显示了我们的LM的收益。我们展示了误差校正前后困惑度量的模型的估计。校正后的困惑越低,k-mer大小越好。我们还表明,用于校正读取的对准率和组装质量与困惑强烈地呈负相关,从而实现了k-mer值的自动选择以获得更好的纠错,因此改善的组装质量。此外,我们表明我们的注意力模型对于整个管道的重大运行时间改善 - 由于并行化注意机制和JIT编译对GPU推理的使用JIT编译,因此整个管道的运行时间更快。
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The word alignment task, despite its prominence in the era of statistical machine translation (SMT), is niche and under-explored today. In this two-part tutorial, we argue for the continued relevance for word alignment. The first part provides a historical background to word alignment as a core component of the traditional SMT pipeline. We zero-in on GIZA++, an unsupervised, statistical word aligner with surprising longevity. Jumping forward to the era of neural machine translation (NMT), we show how insights from word alignment inspired the attention mechanism fundamental to present-day NMT. The second part shifts to a survey approach. We cover neural word aligners, showing the slow but steady progress towards surpassing GIZA++ performance. Finally, we cover the present-day applications of word alignment, from cross-lingual annotation projection, to improving translation.
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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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我们介绍了块状变压器,该变压器以序列的反复方式应用变压器层,并且相对于序列长度具有线性复杂性。我们的复发单元在训练过程中在代币的块而不是单个令牌上运行,并利用块内并行计算,以便有效利用加速器硬件。单元本身非常简单。它仅仅是一个变压器层:它使用自我注意事项和交叉注意力来有效计算大量状态向量和令牌上的复发函数。我们的设计部分受到LSTM单元的启发,它使用LSTM风格的大门,但它可以将典型的LSTM单元缩放为几个数量级。我们的复发实现在计算时间和参数计数中都具有相同的成本作为传统的变压器层,但是在很长的序列中,语言建模任务中的语言建模任务的困惑极大地改善了。我们的模型比远程变压器XL基线的表现宽大,同时运行的速度是两倍。我们证明了它在PG19(书籍),Arxiv论文和GitHub源代码上的有效性。我们的代码已发布为开​​源。
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我用Hunglish2语料库训练神经电脑翻译任务的模型。这项工作的主要贡献在培训NMT模型期间评估不同的数据增强方法。我提出了5种不同的增强方法,这些方法是结构感知的,这意味着而不是随机选择用于消隐或替换的单词,句子的依赖树用作增强的基础。我首先关于神经网络的详细文献综述,顺序建模,神经机翻译,依赖解析和数据增强。经过详细的探索性数据分析和Hunglish2语料库的预处理之后,我使用所提出的数据增强技术进行实验。匈牙利语的最佳型号达到了33.9的BLEU得分,而英国匈牙利最好的模型达到了28.6的BLEU得分。
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在本文中,我们试图通过引入深度学习模型的句法归纳偏见来建立两所学校之间的联系。我们提出了两个归纳偏见的家族,一个家庭用于选区结构,另一个用于依赖性结构。选区归纳偏见鼓励深度学习模型使用不同的单位(或神经元)分别处理长期和短期信息。这种分离为深度学习模型提供了一种方法,可以从顺序输入中构建潜在的层次表示形式,即更高级别的表示由高级表示形式组成,并且可以分解为一系列低级表示。例如,在不了解地面实际结构的情况下,我们提出的模型学会通过根据其句法结构组成变量和运算符的表示来处理逻辑表达。另一方面,依赖归纳偏置鼓励模型在输入序列中找到实体之间的潜在关系。对于自然语言,潜在关系通常被建模为一个定向依赖图,其中一个单词恰好具有一个父节点和零或几个孩子的节点。将此约束应用于类似变压器的模型之后,我们发现该模型能够诱导接近人类专家注释的有向图,并且在不同任务上也优于标准变压器模型。我们认为,这些实验结果为深度学习模型的未来发展展示了一个有趣的选择。
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Neural Machine Translation (NMT) is an end-to-end learning approach for automated translation, with the potential to overcome many of the weaknesses of conventional phrase-based translation systems. Unfortunately, NMT systems are known to be computationally expensive both in training and in translation inference -sometimes prohibitively so in the case of very large data sets and large models. Several authors have also charged that NMT systems lack robustness, particularly when input sentences contain rare words. These issues have hindered NMT's use in practical deployments and services, where both accuracy and speed are essential. In this work, we present GNMT, Google's Neural Machine Translation system, which attempts to address many of these issues. Our model consists of a deep LSTM network with 8 encoder and 8 decoder layers using residual connections as well as attention connections from the decoder network to the encoder. To improve parallelism and therefore decrease training time, our attention mechanism connects the bottom layer of the decoder to the top layer of the encoder. To accelerate the final translation speed, we employ low-precision arithmetic during inference computations. To improve handling of rare words, we divide words into a limited set of common sub-word units ("wordpieces") for both input and output. This method provides a good balance between the flexibility of "character"-delimited models and the efficiency of "word"-delimited models, naturally handles translation of rare words, and ultimately improves the overall accuracy of the system. Our beam search technique employs a length-normalization procedure and uses a coverage penalty, which encourages generation of an output sentence that is most likely to cover all the words in the source sentence. To directly optimize the translation BLEU scores, we consider refining the models by using reinforcement learning, but we found that the improvement in the BLEU scores did not reflect in the human evaluation. On the WMT'14 English-to-French and English-to-German benchmarks, GNMT achieves competitive results to state-of-the-art. Using a human side-by-side evaluation on a set of isolated simple sentences, it reduces translation errors by an average of 60% compared to Google's phrase-based production system.
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状态空间模型已显示在建模远距离依赖性方面有效,特别是序列分类任务。在这项工作中,我们着重于对英语书籍,GitHub源代码和Arxiv数学文章的自回旋序列建模。基于围绕封闭激活功能的有效性的最新发展,我们提出了一个名为“封闭状态空间(GSS)”的新层,并表明它的训练速度明显快于TPU的S4(即DSS)的对角线版本,具有相当竞争力 - 基于变压器的基线,并表现出零击向更长的输入,同时直接实施。最后,我们表明,利用自我意见来建模局部依赖性,可以进一步提高GSS的性能。
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Recent work has improved language models (LMs) remarkably by equipping them with a non-parametric memory component. However, most existing approaches only introduce mem-ories at testing time or represent them using a separately trained encoder, resulting in suboptimal training of the language model. In this work, we present TRIME, a novel yet simple training approach designed for training LMs with memory augmentation. Our approach uses a training objective that directly takes in-batch examples as accessible memory. We also present new methods for memory construction and data batching, which are used for adapting to different sets of memories--local, long-term, and external memory--at testing time. We evaluate TRIME on multiple language modeling and machine translation benchmarks and show that it is able to achieve significant improvements across all the settings. Concretely, TRIME reduces the perplexity from 18.70 to 15.37 on WIKITEXT-103, by effectively leveraging a large memory set from the training corpus. Compared to standard LM training, TRIME adds negligible computational overhead and is compatible with different neural architectures, making it a versatile solution for training memory-augmented LMs.
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The dominant sequence transduction models are based on complex recurrent or convolutional neural networks that include an encoder and a decoder. The best performing models also connect the encoder and decoder through an attention mechanism. We propose a new simple network architecture, the Transformer, based solely on attention mechanisms, dispensing with recurrence and convolutions entirely. Experiments on two machine translation tasks show these models to be superior in quality while being more parallelizable and requiring significantly less time to train. Our model achieves 28.4 BLEU on the WMT 2014 Englishto-German translation task, improving over the existing best results, including ensembles, by over 2 BLEU. On the WMT 2014 English-to-French translation task, our model establishes a new single-model state-of-the-art BLEU score of 41.0 after training for 3.5 days on eight GPUs, a small fraction of the training costs of the best models from the literature. * Equal contribution. Listing order is random. Jakob proposed replacing RNNs with self-attention and started the effort to evaluate this idea. Ashish, with Illia, designed and implemented the first Transformer models and has been crucially involved in every aspect of this work. Noam proposed scaled dot-product attention, multi-head attention and the parameter-free position representation and became the other person involved in nearly every detail. Niki designed, implemented, tuned and evaluated countless model variants in our original codebase and tensor2tensor. Llion also experimented with novel model variants, was responsible for our initial codebase, and efficient inference and visualizations. Lukasz and Aidan spent countless long days designing various parts of and implementing tensor2tensor, replacing our earlier codebase, greatly improving results and massively accelerating our research.† Work performed while at Google Brain.‡ Work performed while at Google Research.
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Grammatical Error Correction (GEC) is the task of automatically detecting and correcting errors in text. The task not only includes the correction of grammatical errors, such as missing prepositions and mismatched subject-verb agreement, but also orthographic and semantic errors, such as misspellings and word choice errors respectively. The field has seen significant progress in the last decade, motivated in part by a series of five shared tasks, which drove the development of rule-based methods, statistical classifiers, statistical machine translation, and finally neural machine translation systems which represent the current dominant state of the art. In this survey paper, we condense the field into a single article and first outline some of the linguistic challenges of the task, introduce the most popular datasets that are available to researchers (for both English and other languages), and summarise the various methods and techniques that have been developed with a particular focus on artificial error generation. We next describe the many different approaches to evaluation as well as concerns surrounding metric reliability, especially in relation to subjective human judgements, before concluding with an overview of recent progress and suggestions for future work and remaining challenges. We hope that this survey will serve as comprehensive resource for researchers who are new to the field or who want to be kept apprised of recent developments.
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Transfer learning, where a model is first pre-trained on a data-rich task before being finetuned on a downstream task, has emerged as a powerful technique in natural language processing (NLP). The effectiveness of transfer learning has given rise to a diversity of approaches, methodology, and practice. In this paper, we explore the landscape of transfer learning techniques for NLP by introducing a unified framework that converts all text-based language problems into a text-to-text format. Our systematic study compares pre-training objectives, architectures, unlabeled data sets, transfer approaches, and other factors on dozens of language understanding tasks. By combining the insights from our exploration with scale and our new "Colossal Clean Crawled Corpus", we achieve state-of-the-art results on many benchmarks covering summarization, question answering, text classification, and more. To facilitate future work on transfer learning for NLP, we release our data set, pre-trained models, and code.
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Scene text spotting is of great importance to the computer vision community due to its wide variety of applications. Recent methods attempt to introduce linguistic knowledge for challenging recognition rather than pure visual classification. However, how to effectively model the linguistic rules in end-to-end deep networks remains a research challenge. In this paper, we argue that the limited capacity of language models comes from 1) implicit language modeling; 2) unidirectional feature representation; and 3) language model with noise input. Correspondingly, we propose an autonomous, bidirectional and iterative ABINet++ for scene text spotting. Firstly, the autonomous suggests enforcing explicitly language modeling by decoupling the recognizer into vision model and language model and blocking gradient flow between both models. Secondly, a novel bidirectional cloze network (BCN) as the language model is proposed based on bidirectional feature representation. Thirdly, we propose an execution manner of iterative correction for the language model which can effectively alleviate the impact of noise input. Finally, to polish ABINet++ in long text recognition, we propose to aggregate horizontal features by embedding Transformer units inside a U-Net, and design a position and content attention module which integrates character order and content to attend to character features precisely. ABINet++ achieves state-of-the-art performance on both scene text recognition and scene text spotting benchmarks, which consistently demonstrates the superiority of our method in various environments especially on low-quality images. Besides, extensive experiments including in English and Chinese also prove that, a text spotter that incorporates our language modeling method can significantly improve its performance both in accuracy and speed compared with commonly used attention-based recognizers.
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我们想要模型的文本单位是什么?从字节到多字表达式,可以在许多粒度下分析和生成文本。直到最近,大多数自然语言处理(NLP)模型通过单词操作,将那些作为离散和原子令牌处理,但从字节对编码(BPE)开始,基于次字的方法在许多领域都变得占主导地位,使得仍然存在小词汇表允许快速推断。是道路字符级模型的结束或字节级处理吗?在这项调查中,我们通过展示和评估基于学习分割的词语和字符以及基于子字的方法的混合方法以及基于学习的分割的杂交方法,连接多行工作。我们得出结论,对于所有应用来说,并且可能永远不会成为所有应用的银子弹奇异解决方案,并且严重思考令牌化对许多应用仍然很重要。
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现实世界中的数据是高维的:即使在压缩后,书籍,图像或音乐表演也很容易包含数十万个元素。但是,最常用的自回归模型,变压器非常昂贵,以缩放捕获这种远程结构所需的输入和层数。我们开发了感知者AR,这是一种自回归的模态 - 不合骨架构,它使用交叉注意力将远程输入映射到少数潜在的潜在,同时还可以维护端到端的因果关系掩盖。感知器AR可以直接进行十万个令牌,从而实现了实用的长篇小写密度估计,而无需手工制作的稀疏模式或记忆机制。当对图像或音乐进行培训时,感知器AR会生成具有清晰长期连贯性和结构的输出。我们的架构还获得了长期基准测试的最新可能性,包括64 x 64个Imagenet图像和PG-19书籍。
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Large pretrained language models generate fluent text but are notoriously hard to controllably sample from. In this work, we study constrained sampling from such language models: generating text that satisfies user-defined constraints, while maintaining fluency and the model's performance in a downstream task. We propose MuCoLa -- a sampling procedure that combines the log-likelihood of the language model with arbitrary (differentiable) constraints in a single energy function, and then generates samples in a non-autoregressive manner. Specifically, it initializes the entire output sequence with noise and follows a Markov chain defined by Langevin Dynamics using the gradients of the energy function. We evaluate MuCoLa on text generation with soft and hard constraints as well as their combinations obtaining significant improvements over competitive baselines for toxicity avoidance, sentiment control, and keyword-guided generation.
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确保适当的标点符号和字母外壳是朝向应用复杂的自然语言处理算法的关键预处理步骤。这对于缺少标点符号和壳体的文本源,例如自动语音识别系统的原始输出。此外,简短的短信和微博的平台提供不可靠且经常错误的标点符号和套管。本调查概述了历史和最先进的技术,用于恢复标点符号和纠正单词套管。此外,突出了当前的挑战和研究方向。
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上下文感知的str方法通常使用内部自回旋(AR)语言模型(LM)。 AR模型的固有局限性动机是采用外部LM的两阶段方法。输入图像上外部LM的条件独立性可能导致其错误地纠正正确的预测,从而导致明显的低效率。我们的方法Parseq使用置换语言建模学习了具有共同权重的内部AR LMS集合。它统一了无上下文的非AR和上下文感知的AR推断,并使用双向上下文统一了迭代的精致。使用合成训练数据,Parseq实现了最新的(SOTA),从而获得了Str基准(精度为91.9%)和更具挑战性的数据集。在对实际数据进行培训时,它建立了新的SOTA结果(精度为96.0%)。 Parseq由于其简单,统一的结构和平行的令牌处理,对准确性与参数计数,拖放和延迟非常最佳。由于其广泛使用了注意力,它对在现实世界图像中常见的任意导向文本具有鲁棒性。代码,预处理的权重和数据可在以下网址提供:https://github.com/baudm/parseq。
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基于变压器的模型在多个领域和任务上显示了它们的有效性。自我注意力允许将所有序列元素的信息结合到上下文感知表示形式中。但是,全球和本地信息必须主要存储在相同的元素表示中。此外,输入序列的长度受到自我注意的二次计算复杂性的限制。在这项工作中,我们提出并研究了一个记忆启动的片段级循环变压器(复发记忆变压器)。内存允许借助复发的帮助存储和处理本地和全局信息,并可以在长序列的段之间传递信息。我们通过将特殊的内存令牌添加到输入或输出序列中,实现了一个内存机制,无需更改变压器模型。然后,对变压器进行了训练,以控制内存操作和序列表示处理。实验的结果表明,我们的模型与Transformer-XL在语言建模上的较小内存大小上的表现相同,并在需要更长序列处理的任务方面胜过它。我们证明,将内存令牌添加到TR-XL可以提高IT性能。这使得反复的内存变压器成为需要学习长期依赖性和内存处理中的通用性(例如算法任务和推理)的应用程序的有前途的体系结构。
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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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