最近,培训预培训方法在以任务为导向的对话框(TOD)系统中表现出了很大的成功。但是,大多数现有的预培训模型用于TOD专注于对话的理解或对话生成,但并非两者兼而有之。在本文中,我们提出了Space-3,这是一种新型的统一的半监督预培训的预训练的对话模型,从大规模对话CORPORA中学习有限的注释,可以有效地对广泛的下游对话任务进行微调。具体而言,Space-3由单个变压器中的四个连续组件组成,以维护TOD系统中的任务流:(i)对话框编码模块编码对话框历史记录,(ii)对话框理解模块以从任一用户中提取语义向量查询或系统响应,(iii)一个对话框策略模块,以生成包含响应高级语义的策略向量,以及(iv)对话框生成模块以产生适当的响应。我们为每个组件设计一个专门的预训练目标。具体而言,我们预先培训对话框编码模块,使用跨度掩码语言建模,以学习上下文化对话框信息。为了捕获“结构化对话框”语义,我们通过额外的对话注释通过新颖的树诱导的半监视对比度学习目标来预先培训对话框理解模块。此外,我们通过将其输出策略向量与响应响应的语义向量之间的L2距离最小化以进行策略优化,从而预先培训对话策略模块。最后,对话框生成模型由语言建模预先训练。结果表明,Space-3在八个下游对话框基准中实现最新性能,包括意图预测,对话框状态跟踪和端到端对话框建模。我们还表明,在低资源设置下,Space-3比现有模型具有更强的射击能力。
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具有对比性学习目标的预训练方法在对话了解任务中表现出了显着的成功。但是,当前的对比学习仅将自调查的对话样本视为正样本,并将所有其他对话样本视为负面样本,即使在语义上相关的对话框中,也会强制执行不同的表示。在本文中,我们提出了一个树木结构化的预培训对话模型Space-2,该模型从有限标记的对话框和大规模的无标记的对话框COLPORA通过半监督的对比度预培训来学习对话框表示。具体而言,我们首先定义一个通用的语义树结构(STS),以统一不同对话框数据集的注释模式,以便可以利用所有标记数据中存储的丰富结构信息。然后,我们提出了一个新颖的多视图分数功能,以增加共享类似STS的所有可能对话框的相关性,并且在监督的对比预训练期间仅推开其他完全不同的对话框。为了充分利用未标记的对话,还增加了基本的自我监督对比损失,以完善学习的表示。实验表明,我们的方法可以在DialogLue基准测试中实现新的最新结果,该基准由七个数据集和四个流行的对话框组成。为了获得可重复性,我们在https://github.com/alibabaresearch/damo-convai/tree/main/main/space-2上发布代码和数据。
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预先训练的模型已经证明是强大的增强面向任务的对话系统。但是,目前的预训练方法主要关注增强对话的理解和生成任务,同时忽略对话策略的开发。在本文中,我们提出了一个小说预先训练的对话模型,明确地通过半监督学习明确地从有限标记的对话框和大规模未标记的对话框中学习对话策略。具体而言,我们在预训练期间介绍一个对话框预测任务,以便在预训练中进行策略优化,并使用一致性正则化术语在未标记的对话的帮助下优化学习的表示。我们还实施了一个浇注机制来称量合适的未标记对话框样本。经验结果表明,星系大大提高了面向任务为导向的对话系统的性能,并在基准数据集中实现了新的最先进结果:车载,多种多纤2.0和多纺,改善其端到端合并分数2.5,5.3和5.5分。我们还显示Galaxy比各种低资源设置下的现有模型更强大的少量射击能力。
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Designing experiments often requires balancing between learning about the true treatment effects and earning from allocating more samples to the superior treatment. While optimal algorithms for the Multi-Armed Bandit Problem (MABP) provide allocation policies that optimally balance learning and earning, they tend to be computationally expensive. The Gittins Index (GI) is a solution to the MABP that can simultaneously attain optimality and computationally efficiency goals, and it has been recently used in experiments with Bernoulli and Gaussian rewards. For the first time, we present a modification of the GI rule that can be used in experiments with exponentially-distributed rewards. We report its performance in simulated 2- armed and 3-armed experiments. Compared to traditional non-adaptive designs, our novel GI modified design shows operating characteristics comparable in learning (e.g. statistical power) but substantially better in earning (e.g. direct benefits). This illustrates the potential that designs using a GI approach to allocate participants have to improve participant benefits, increase efficiencies, and reduce experimental costs in adaptive multi-armed experiments with exponential rewards.
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Transformer has achieved impressive successes for various computer vision tasks. However, most of existing studies require to pretrain the Transformer backbone on a large-scale labeled dataset (e.g., ImageNet) for achieving satisfactory performance, which is usually unavailable for medical images. Additionally, due to the gap between medical and natural images, the improvement generated by the ImageNet pretrained weights significantly degrades while transferring the weights to medical image processing tasks. In this paper, we propose Bootstrap Own Latent of Transformer (BOLT), a self-supervised learning approach specifically for medical image classification with the Transformer backbone. Our BOLT consists of two networks, namely online and target branches, for self-supervised representation learning. Concretely, the online network is trained to predict the target network representation of the same patch embedding tokens with a different perturbation. To maximally excavate the impact of Transformer from limited medical data, we propose an auxiliary difficulty ranking task. The Transformer is enforced to identify which branch (i.e., online/target) is processing the more difficult perturbed tokens. Overall, the Transformer endeavours itself to distill the transformation-invariant features from the perturbed tokens to simultaneously achieve difficulty measurement and maintain the consistency of self-supervised representations. The proposed BOLT is evaluated on three medical image processing tasks, i.e., skin lesion classification, knee fatigue fracture grading and diabetic retinopathy grading. The experimental results validate the superiority of our BOLT for medical image classification, compared to ImageNet pretrained weights and state-of-the-art self-supervised learning approaches.
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Text clustering and topic extraction are two important tasks in text mining. Usually, these two tasks are performed separately. For topic extraction to facilitate clustering, we can first project texts into a topic space and then perform a clustering algorithm to obtain clusters. To promote topic extraction by clustering, we can first obtain clusters with a clustering algorithm and then extract cluster-specific topics. However, this naive strategy ignores the fact that text clustering and topic extraction are strongly correlated and follow a chicken-and-egg relationship. Performing them separately fails to make them mutually benefit each other to achieve the best overall performance. In this paper, we propose an unsupervised text clustering and topic extraction framework (ClusTop) which integrates text clustering and topic extraction into a unified framework and can achieve high-quality clustering result and extract topics from each cluster simultaneously. Our framework includes four components: enhanced language model training, dimensionality reduction, clustering and topic extraction, where the enhanced language model can be viewed as a bridge between clustering and topic extraction. On one hand, it provides text embeddings with a strong cluster structure which facilitates effective text clustering; on the other hand, it pays high attention on the topic related words for topic extraction because of its self-attention architecture. Moreover, the training of enhanced language model is unsupervised. Experiments on two datasets demonstrate the effectiveness of our framework and provide benchmarks for different model combinations in this framework.
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This paper illustrates the technologies of user next intent prediction with a concept knowledge graph. The system has been deployed on the Web at Alipay, serving more than 100 million daily active users. Specifically, we propose AlipayKG to explicitly characterize user intent, which is an offline concept knowledge graph in the Life-Service domain modeling the historical behaviors of users, the rich content interacted by users and the relations between them. We further introduce a Transformer-based model which integrates expert rules from the knowledge graph to infer the online user's next intent. Experimental results demonstrate that the proposed system can effectively enhance the performance of the downstream tasks while retaining explainability.
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Capturing feature information effectively is of great importance in vision tasks. With the development of convolutional neural networks (CNNs), concepts like residual connection and multiple scales promote continual performance gains on diverse deep learning vision tasks. However, the existing methods do not organically combined advantages of these valid ideas. In this paper, we propose a novel CNN architecture called GoogLe2Net, it consists of residual feature-reutilization inceptions (ResFRI) or split residual feature-reutilization inceptions (Split-ResFRI) which create transverse passages between adjacent groups of convolutional layers to enable features flow to latter processing branches and possess residual connections to better process information. Our GoogLe2Net is able to reutilize information captured by foregoing groups of convolutional layers and express multi-scale features at a fine-grained level, which improves performances in image classification. And the inception we proposed could be embedded into inception-like networks directly without any migration costs. Moreover, in experiments based on popular vision datasets, such as CIFAR10 (97.94%), CIFAR100 (85.91%) and Tiny Imagenet (70.54%), we obtain better results on image classification task compared with other modern models.
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Despite some successful applications of goal-driven navigation, existing deep reinforcement learning-based approaches notoriously suffers from poor data efficiency issue. One of the reasons is that the goal information is decoupled from the perception module and directly introduced as a condition of decision-making, resulting in the goal-irrelevant features of the scene representation playing an adversary role during the learning process. In light of this, we present a novel Goal-guided Transformer-enabled reinforcement learning (GTRL) approach by considering the physical goal states as an input of the scene encoder for guiding the scene representation to couple with the goal information and realizing efficient autonomous navigation. More specifically, we propose a novel variant of the Vision Transformer as the backbone of the perception system, namely Goal-guided Transformer (GoT), and pre-train it with expert priors to boost the data efficiency. Subsequently, a reinforcement learning algorithm is instantiated for the decision-making system, taking the goal-oriented scene representation from the GoT as the input and generating decision commands. As a result, our approach motivates the scene representation to concentrate mainly on goal-relevant features, which substantially enhances the data efficiency of the DRL learning process, leading to superior navigation performance. Both simulation and real-world experimental results manifest the superiority of our approach in terms of data efficiency, performance, robustness, and sim-to-real generalization, compared with other state-of-art baselines. Demonstration videos are available at \colorb{https://youtu.be/93LGlGvaN0c.
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Despite the success of large language models (LLMs) in various natural language processing (NLP) tasks, the stored knowledge in these models may inevitably be incomplete, out-of-date, or incorrect. This motivates the need to utilize external knowledge to assist LLMs. Unfortunately, current methods for incorporating external knowledge often require additional training or fine-tuning, which can be costly and may not be feasible for LLMs. To address this issue, we propose a novel post-processing approach, rethinking with retrieval (RR), which retrieves relevant external knowledge based on the decomposed reasoning steps obtained from the chain-of-thought (CoT) prompting. This lightweight approach does not require additional training or fine-tuning and is not limited by the input length of LLMs. We evaluate the effectiveness of RR through extensive experiments with GPT-3 on three complex reasoning tasks: commonsense reasoning, temporal reasoning, and tabular reasoning. Our results show that RR can produce more faithful explanations and improve the performance of LLMs.
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