Recurrent neural networks are a widely used class of neural architectures. They have, however, two shortcomings. First, they are often treated as black-box models and as such it is difficult to understand what exactly they learn as well as how they arrive at a particular prediction. Second, they tend to work poorly on sequences requiring long-term memorization, despite having this capacity in principle. We aim to address both shortcomings with a class of recurrent networks that use a stochastic state transition mechanism between cell applications. This mechanism, which we term state-regularization, makes RNNs transition between a finite set of learnable states. We evaluate state-regularized RNNs on (1) regular languages for the purpose of automata extraction; (2) non-regular languages such as balanced parentheses and palindromes where external memory is required; and (3) real-word sequence learning tasks for sentiment analysis, visual object recognition and text categorisation. We show that state-regularization (a) simplifies the extraction of finite state automata that display an RNN's state transition dynamic; (b) forces RNNs to operate more like automata with external memory and less like finite state machines, which potentiality leads to a more structural memory; (c) leads to better interpretability and explainability of RNNs by leveraging the probabilistic finite state transition mechanism over time steps.

可靠的概括是安全ML和AI的核心。但是，了解神经网络何时以及如何推广仍然是该领域最重要的未解决问题之一。在这项工作中，我们进行了一项广泛的实证研究（2200个模型，16个任务），以研究计算理论中的见解是否可以预测实践中神经网络概括的局限性。我们证明，根据Chomsky层次结构进行分组任务使我们能够预测某些架构是否能够推广到分布外输入。这包括负面结果，即使大量数据和训练时间也不会导致任何非平凡的概括，尽管模型具有足够的能力完美地适合培训数据。我们的结果表明，对于我们的任务子集，RNN和变形金刚无法概括非规范的任务，LSTMS可以解决常规和反语言任务，并且只有通过结构化内存（例如堆栈或存储器磁带）可以增强的网络可以成功地概括了无上下文和上下文敏感的任务。

We present a differentiable stack data structure that simultaneously and tractably encodes an exponential number of stack configurations, based on Lang's algorithm for simulating nondeterministic pushdown automata. We call the combination of this data structure with a recurrent neural network (RNN) controller a Nondeterministic Stack RNN. We compare our model against existing stack RNNs on various formal languages, demonstrating that our model converges more reliably to algorithmic behavior on deterministic tasks, and achieves lower cross-entropy on inherently nondeterministic tasks.

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。

Common to all different kinds of recurrent neural networks (RNNs) is the intention to model relations between data points through time. When there is no immediate relationship between subsequent data points (like when the data points are generated at random, e.g.), we show that RNNs are still able to remember a few data points back into the sequence by memorizing them by heart using standard backpropagation. However, we also show that for classical RNNs, LSTM and GRU networks the distance of data points between recurrent calls that can be reproduced this way is highly limited (compared to even a loose connection between data points) and subject to various constraints imposed by the type and size of the RNN in question. This implies the existence of a hard limit (way below the information-theoretic one) for the distance between related data points within which RNNs are still able to recognize said relation.

这是一门专门针对STEM学生开发的介绍性机器学习课程。我们的目标是为有兴趣的读者提供基础知识，以在自己的项目中使用机器学习，并将自己熟悉术语作为进一步阅读相关文献的基础。在这些讲义中，我们讨论受监督，无监督和强化学习。注释从没有神经网络的机器学习方法的说明开始，例如原理分析，T-SNE，聚类以及线性回归和线性分类器。我们继续介绍基本和先进的神经网络结构，例如密集的进料和常规神经网络，经常性的神经网络，受限的玻尔兹曼机器，（变性）自动编码器，生成的对抗性网络。讨论了潜在空间表示的解释性问题，并使用梦和对抗性攻击的例子。最后一部分致力于加强学习，我们在其中介绍了价值功能和政策学习的基本概念。

In this paper we compare different types of recurrent units in recurrent neural networks (RNNs). Especially, we focus on more sophisticated units that implement a gating mechanism, such as a long short-term memory (LSTM) unit and a recently proposed gated recurrent unit (GRU). We evaluate these recurrent units on the tasks of polyphonic music modeling and speech signal modeling. Our experiments revealed that these advanced recurrent units are indeed better than more traditional recurrent units such as tanh units. Also, we found GRU to be comparable to LSTM.

当前独立于域的经典计划者需要问题域和实例作为输入的符号模型，从而导致知识采集瓶颈。同时，尽管深度学习在许多领域都取得了重大成功，但知识是在与符号系统（例如计划者）不兼容的亚符号表示中编码的。我们提出了Latplan，这是一种无监督的建筑，结合了深度学习和经典计划。只有一组未标记的图像对，显示了环境中允许的过渡子集（训练输入），Latplan学习了环境的完整命题PDDL动作模型。稍后，当给出代表初始状态和目标状态（计划输入）的一对图像时，Latplan在符号潜在空间中找到了目标状态的计划，并返回可视化的计划执行。我们使用6个计划域的基于图像的版本来评估LATPLAN：8个插头，15个式嘴，Blockworld，Sokoban和两个LightsOut的变体。

Learning hierarchical structures in sequential data -- from simple algorithmic patterns to natural language -- in a reliable, generalizable way remains a challenging problem for neural language models. Past work has shown that recurrent neural networks (RNNs) struggle to generalize on held-out algorithmic or syntactic patterns without supervision or some inductive bias. To remedy this, many papers have explored augmenting RNNs with various differentiable stacks, by analogy with finite automata and pushdown automata (PDAs). In this paper, we improve the performance of our recently proposed Nondeterministic Stack RNN (NS-RNN), which uses a differentiable data structure that simulates a nondeterministic PDA, with two important changes. First, the model now assigns unnormalized positive weights instead of probabilities to stack actions, and we provide an analysis of why this improves training. Second, the model can directly observe the state of the underlying PDA. Our model achieves lower cross-entropy than all previous stack RNNs on five context-free language modeling tasks (within 0.05 nats of the information-theoretic lower bound), including a task on which the NS-RNN previously failed to outperform a deterministic stack RNN baseline. Finally, we propose a restricted version of the NS-RNN that incrementally processes infinitely long sequences, and we present language modeling results on the Penn Treebank.

In this paper, we propose a novel neural network model called RNN Encoder-Decoder that consists of two recurrent neural networks (RNN). One RNN encodes a sequence of symbols into a fixedlength vector representation, and the other decodes the representation into another sequence of symbols. The encoder and decoder of the proposed model are jointly trained to maximize the conditional probability of a target sequence given a source sequence. The performance of a statistical machine translation system is empirically found to improve by using the conditional probabilities of phrase pairs computed by the RNN Encoder-Decoder as an additional feature in the existing log-linear model. Qualitatively, we show that the proposed model learns a semantically and syntactically meaningful representation of linguistic phrases.

在部分可观察域中的预测和规划的常见方法是使用经常性的神经网络（RNN），其理想地开发和维持关于隐藏，任务相关因素的潜伏。我们假设物理世界中的许多这些隐藏因素随着时间的推移是恒定的，而只是稀疏变化。为研究这一假设，我们提出了Gated $ L_0 $正规化的动态（Gatel0rd），一种新的经常性架构，它包含归纳偏差，以保持稳定，疏口改变潜伏状态。通过新颖的内部门控功能和潜在状态变化的$ l_0 $ norm的惩罚来实现偏差。我们证明Gatel0rd可以在各种部分可观察到的预测和控制任务中与最先进的RNN竞争或优于最先进的RNN。 Gatel0rd倾向于编码环境的基础生成因子，忽略了虚假的时间依赖性，并概括了更好的，提高了基于模型的规划和加强学习任务中的采样效率和整体性能。此外，我们表明可以容易地解释开发的潜在状态，这是朝着RNN中更好地解释的步骤。

近年来，使用正交矩阵已被证明是通过训练，稳定性和收敛尤其是控制梯度来改善复发性神经网络（RNN）的一种有希望的方法。通过使用各种门和记忆单元，封闭的复发单元（GRU）和长期短期记忆（LSTM）体系结构解决了消失的梯度问题，但它们仍然容易出现爆炸梯度问题。在这项工作中，我们分析了GRU中的梯度，并提出了正交矩阵的使用，以防止梯度问题爆炸并增强长期记忆。我们研究了在哪里使用正交矩阵，并提出了基于Neumann系列的缩放尺度的Cayley转换，以训练GRU中的正交矩阵，我们称之为Neumann-cayley Orthoconal orthoconal Gru或简单的NC-GRU。我们介绍了有关几个合成和现实世界任务的模型的详细实验，这些实验表明NC-GRU明显优于GRU以及其他几个RNN。

当前信息时代在互联网上产生的数据的指数增长是数字经济的推动力。信息提取是累积大数据中的主要价值。对统计分析和手工设计的规则机器学习算法的大数据依赖性被人类语言固有的巨大复杂性所淹没。自然语言处理（NLP）正在装备机器，以了解这些人类多样化和复杂的语言。文本分类是一个NLP任务，它会自动识别基于预定义或未定标记的集合的模式。常见的文本分类应用程序包括信息检索，建模新闻主题，主题提取，情感分析和垃圾邮件检测。在文本中，某些单词序列取决于上一个或下一个单词序列以使其充分含义。这是一项具有挑战性的依赖性任务，要求机器能够存储一些以前的重要信息以影响未来的含义。诸如RNN，GRU和LSTM之类的序列模型是具有长期依赖性任务的突破。因此，我们将这些模型应用于二进制和多类分类。产生的结果非常出色，大多数模型在80％和94％的范围内执行。但是，这个结果并不详尽，因为我们认为如果机器要与人类竞争，可以改进。

Models based on deep convolutional networks have dominated recent image interpretation tasks; we investigate whether models which are also recurrent, or "temporally deep", are effective for tasks involving sequences, visual and otherwise. We develop a novel recurrent convolutional architecture suitable for large-scale visual learning which is end-to-end trainable, and demonstrate the value of these models on benchmark video recognition tasks, image description and retrieval problems, and video narration challenges. In contrast to current models which assume a fixed spatio-temporal receptive field or simple temporal averaging for sequential processing, recurrent convolutional models are "doubly deep" in that they can be compositional in spatial and temporal "layers". Such models may have advantages when target concepts are complex and/or training data are limited. Learning long-term dependencies is possible when nonlinearities are incorporated into the network state updates. Long-term RNN models are appealing in that they directly can map variable-length inputs (e.g., video frames) to variable length outputs (e.g., natural language text) and can model complex temporal dynamics; yet they can be optimized with backpropagation. Our recurrent long-term models are directly connected to modern visual convnet models and can be jointly trained to simultaneously learn temporal dynamics and convolutional perceptual representations. Our results show such models have distinct advantages over state-of-the-art models for recognition or generation which are separately defined and/or optimized.

具有诸如LSTM或GRU之类的门控机制的经常性神经网络是模拟顺序数据的强大工具。在机制中，最近被引入到RNN中的隐藏状态下控制信息流的忘记门被重新解释为状态的时间尺度的代表，即RNN保留信息的时间在输入上。在此解释的基础上，已经提出了几种参数初始化方法，以利用数据依赖于数据中的时间依赖性的知识，以提高可读性。然而，解释依赖于各种不切实际的假设，例如在一定时间点之后没有输入。在这项工作中，我们重新考虑了忘记门的解释，更现实的环境。我们首先概括了所存在的网格RNN理论，以便我们可以考虑连续给出输入的情况。然后，我们争论作为时间表示的忘记门的解释是有效的，当随着时间的推移时，当相对于国家的损失的梯度减小时是有效的。我们经验证明现有的RNNS在初始训练阶段满足了几个任务的初始训练阶段，这与先前的初始化方法很好。在此发现的基础上，我们提出了一种构建新的RNN的方法，可以代表比传统模型更长的时间级，这将提高长期顺序数据的可读性。通过使用现实世界数据集的实验，我们验证了我们的方法的有效性。

Recent neural network sequence models with softmax classifiers have achieved their best language modeling performance only with very large hidden states and large vocabularies. Even then they struggle to predict rare or unseen words even if the context makes the prediction unambiguous. We introduce the pointer sentinel mixture architecture for neural sequence models which has the ability to either reproduce a word from the recent context or produce a word from a standard softmax classifier. Our pointer sentinel-LSTM model achieves state of the art language modeling performance on the Penn Treebank (70.9 perplexity) while using far fewer parameters than a standard softmax LSTM. In order to evaluate how well language models can exploit longer contexts and deal with more realistic vocabularies and larger corpora we also introduce the freely available WikiText corpus. 1

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.

众所周知，端到端的神经NLP体系结构很难理解，这引起了近年来为解释性建模的许多努力。模型解释的基本原则是忠诚，即，解释应准确地代表模型预测背后的推理过程。这项调查首先讨论了忠诚的定义和评估及其对解释性的意义。然后，我们通过将方法分为五类来介绍忠实解释的最新进展：相似性方法，模型内部结构的分析，基于反向传播的方法，反事实干预和自我解释模型。每个类别将通过其代表性研究，优势和缺点来说明。最后，我们从它们的共同美德和局限性方面讨论了上述所有方法，并反思未来的工作方向忠实的解释性。对于有兴趣研究可解释性的研究人员，这项调查将为该领域提供可访问且全面的概述，为进一步探索提供基础。对于希望更好地了解自己的模型的用户，该调查将是一项介绍性手册，帮助选择最合适的解释方法。

“轨迹”是指由地理空间中的移动物体产生的迹线，通常由一系列按时间顺序排列的点表示，其中每个点由地理空间坐标集和时间戳组成。位置感应和无线通信技术的快速进步使我们能够收集和存储大量的轨迹数据。因此，许多研究人员使用轨迹数据来分析各种移动物体的移动性。在本文中，我们专注于“城市车辆轨迹”，这是指城市交通网络中车辆的轨迹，我们专注于“城市车辆轨迹分析”。城市车辆轨迹分析提供了前所未有的机会，可以了解城市交通网络中的车辆运动模式，包括以用户为中心的旅行经验和系统范围的时空模式。城市车辆轨迹数据的时空特征在结构上相互关联，因此，许多先前的研究人员使用了各种方法来理解这种结构。特别是，由于其强大的函数近似和特征表示能力，深度学习模型是由于许多研究人员的注意。因此，本文的目的是开发基于深度学习的城市车辆轨迹分析模型，以更好地了解城市交通网络的移动模式。特别是，本文重点介绍了两项研究主题，具有很高的必要性，重要性和适用性：下一个位置预测，以及合成轨迹生成。在这项研究中，我们向城市车辆轨迹分析提供了各种新型模型，使用深度学习。

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.