Long document retrieval aims to fetch query-relevant documents from a large-scale collection, where knowledge distillation has become de facto to improve a retriever by mimicking a heterogeneous yet powerful cross-encoder. However, in contrast to passages or sentences, retrieval on long documents suffers from the scope hypothesis that a long document may cover multiple topics. This maximizes their structure heterogeneity and poses a granular-mismatch issue, leading to an inferior distillation efficacy. In this work, we propose a new learning framework, fine-grained distillation (FGD), for long-document retrievers. While preserving the conventional dense retrieval paradigm, it first produces global-consistent representations crossing different fine granularity and then applies multi-granular aligned distillation merely during training. In experiments, we evaluate our framework on two long-document retrieval benchmarks, which show state-of-the-art performance.
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With the success of the prompt-tuning paradigm in Natural Language Processing (NLP), various prompt templates have been proposed to further stimulate specific knowledge for serving downstream tasks, e.g., machine translation, text generation, relation extraction, and so on. Existing prompt templates are mainly shared among all training samples with the information of task description. However, training samples are quite diverse. The sharing task description is unable to stimulate the unique task-related information in each training sample, especially for tasks with the finite-label space. To exploit the unique task-related information, we imitate the human decision process which aims to find the contrastive attributes between the objective factual and their potential counterfactuals. Thus, we propose the \textbf{C}ounterfactual \textbf{C}ontrastive \textbf{Prompt}-Tuning (CCPrompt) approach for many-class classification, e.g., relation classification, topic classification, and entity typing. Compared with simple classification tasks, these tasks have more complex finite-label spaces and are more rigorous for prompts. First of all, we prune the finite label space to construct fact-counterfactual pairs. Then, we exploit the contrastive attributes by projecting training instances onto every fact-counterfactual pair. We further set up global prototypes corresponding with all contrastive attributes for selecting valid contrastive attributes as additional tokens in the prompt template. Finally, a simple Siamese representation learning is employed to enhance the robustness of the model. We conduct experiments on relation classification, topic classification, and entity typing tasks in both fully supervised setting and few-shot setting. The results indicate that our model outperforms former baselines.
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Proper functioning of connected and automated vehicles (CAVs) is crucial for the safety and efficiency of future intelligent transport systems. Meanwhile, transitioning to fully autonomous driving requires a long period of mixed autonomy traffic, including both CAVs and human-driven vehicles. Thus, collaboration decision-making for CAVs is essential to generate appropriate driving behaviors to enhance the safety and efficiency of mixed autonomy traffic. In recent years, deep reinforcement learning (DRL) has been widely used in solving decision-making problems. However, the existing DRL-based methods have been mainly focused on solving the decision-making of a single CAV. Using the existing DRL-based methods in mixed autonomy traffic cannot accurately represent the mutual effects of vehicles and model dynamic traffic environments. To address these shortcomings, this article proposes a graph reinforcement learning (GRL) approach for multi-agent decision-making of CAVs in mixed autonomy traffic. First, a generic and modular GRL framework is designed. Then, a systematic review of DRL and GRL methods is presented, focusing on the problems addressed in recent research. Moreover, a comparative study on different GRL methods is further proposed based on the designed framework to verify the effectiveness of GRL methods. Results show that the GRL methods can well optimize the performance of multi-agent decision-making for CAVs in mixed autonomy traffic compared to the DRL methods. Finally, challenges and future research directions are summarized. This study can provide a valuable research reference for solving the multi-agent decision-making problems of CAVs in mixed autonomy traffic and can promote the implementation of GRL-based methods into intelligent transportation systems. The source code of our work can be found at https://github.com/Jacklinkk/Graph_CAVs.
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联合学习(FL)是一种机器学习范式,允许分散的客户在不共享其私人数据的情况下进行协作学习。但是,过度的计算和沟通要求对当前的FL框架构成挑战,尤其是在训练大型模型时。为了防止这些问题阻碍FL系统的部署,我们提出了一个轻巧的框架,客户共同学习融合由多个固定预训练的模型生成的表示形式,而不是从SCRATCH培训大型模型。这通过考虑如何从预先训练的模型中捕获更多特定于客户的信息,并共同提高每个客户利用这些现成模型的能力,从而导致我们解决了一个更实用的FL问题。在这项工作中,我们设计了一种联合原型对比度学习(FEDPCL)方法,该方法通过其类原型共享客户的知识,并以原型对比度方式构建特定于客户的表示。共享原型而不是可学习的模型参数可以使每个客户以个性化的方式融合表示表示,同时以紧凑的形式保持共享知识以进行有效的通信。我们在轻量级框架中对拟议的FEDPCL进行了彻底的评估,以测量和可视化其在流行的FL数据集上融合各种预训练模型的能力。
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我们为时间动作细分任务提供了半监督的学习方法。该任务的目的是在长时间的未修剪程序视频中暂时检测和细分动作,其中只有一小部分视频被密集标记,并且没有标记的大量视频。为此,我们为未标记的数据提出了两个新的损失函数:动作亲和力损失和动作连续性损失。动作亲和力损失通过施加从标记的集合引起的动作先验来指导未标记的样品学习。动作连续性损失强制执行动作的时间连续性,这也提供了框架分类的监督。此外,我们提出了一种自适应边界平滑(ABS)方法,以建立更粗糙的动作边界,以实现更健壮和可靠的学习。在三个基准上评估了拟议的损失函数和ABS。结果表明,它们以较低的标记数据(5%和10%)的数据显着改善了动作细分性能,并获得了与50%标记数据的全面监督相当的结果。此外,当将ABS整合到完全监督的学习中时,ABS成功地提高了性能。
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排名者在事实上的“检索和rerank”管道中起着必不可少的作用,但其训练仍然落后 - 从中​​度的负面因素或/和/和/和作为回收者的辅助模块中学习。在这项工作中,我们首先确定了强大的排名者的两个主要障碍,即是由训练有素的回猎犬和非理想的负面负面的固有标签噪声,该噪声是为高能力的排名所采样的。因此,我们提出多个检索器,因为负面发电机改善了排名者的鲁棒性,其中i)涉及广泛的分发标签噪声,使排名者与每个噪声分布相对,而ii)与排名相对较接近排名负分配,导致更具挑战性的培训。为了评估我们的强大排名者(称为r $^2 $ anker),我们在各种环境中进行了有关流行通道检索基准测试的各种实验,包括BM25级,全等级,回收者蒸馏等。经验结果验证了新的州 - 新州 - 新州 - 我们模型的效果。
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知识共享和模型个性化是应对联邦学习(FL)中非IID挑战的重要组成部分。大多数现有的FL方法侧重于两个极端:1)学习共享模型,以使用非IID数据为所有客户提供服务,以及2)为每个客户(即个性化fl)学习个性化模型。有一个权衡解决方案,即群集或集群个性化的FL,旨在将相似的客户聚集到一个集群中,然后在集群中为所有客户学习共享模型。本文是通过将群集群集制定为可以统一现有方法的双层优化框架来重新审视群集的研究。我们提出了一个新的理论分析框架,以通过考虑客户之间的凝聚力来证明融合。此外,我们以一种称为加权聚类联合学习(WECFL)的算法体现了该框架。经验分析验证了理论结果,并证明了在拟议的集群非IID设置下提出的WECFL的有效性。
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本文旨在统一非欧几里得空间中的空间依赖性和时间依赖性,同时捕获流量数据的内部空间依赖性。对于具有拓扑结构的时空属性实体,时空是连续的和统一的,而每个节点的当前状态都受到每个邻居的变异时期的邻居的过去状态的影响。大多数用于流量预测研究的空间依赖性和时间相关性的空间神经网络在处理中分别损害了时空完整性,而忽略了邻居节点的时间依赖期可以延迟和动态的事实。为了建模这种实际条件,我们提出了一种新型的空间 - 周期性图神经网络,将空间和时间视为不可分割的整体,以挖掘时空图,同时通过消息传播机制利用每个节点的发展时空依赖性。进行消融和参数研究的实验已经验证了拟议的遍及术的有效性,并且可以从https://github.com/nnzhan/traversenet中找到详细的实现。
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图形卷积网络对于从图形结构数据进行深入学习而变得必不可少。大多数现有的图形卷积网络都有两个大缺点。首先,它们本质上是低通滤波器,因此忽略了图形信号的潜在有用的中和高频带。其次,固定了现有图卷积过滤器的带宽。图形卷积过滤器的参数仅转换图输入而不更改图形卷积滤波器函数的曲率。实际上,除非我们有专家领域知识,否则我们不确定是否应该在某个点保留或切断频率。在本文中,我们建议自动图形卷积网络(AUTOGCN)捕获图形信号的完整范围,并自动更新图形卷积过滤器的带宽。虽然它基于图谱理论,但我们的自动环境也位于空间中,并具有空间形式。实验结果表明,AutoGCN比仅充当低通滤波器的基线方法实现了显着改善。
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在联合学习(FL)中的客户端的异质性通常会在梯度空间中发生客户的知识聚合时阻碍优化融合和泛化性能。例如,客户端可以在数据分发,网络延迟,输入/输出空间和/或模型架构方面不同,这可以很容易地导致其本地梯度的未对准。为了提高异质性的容忍度,我们提出了一种新的联合原型学习(FedProto)框架,其中客户端和服务器传达了抽象类原型而不是梯度。 FEDPROTO聚合从不同客户端收集的本地原型,然后将全局原型发送回所有客户端,以规范本地模型的培训。每个客户端的训练旨在最大限度地减少本地数据上的分类错误,同时保持所产生的本地原型靠近相应的全球范围。此外,我们在非凸起目标下对FedProto的收敛速度提供了理论分析。在实验中,我们提出了一种针对异构FL定制的基准设置,FEDPROTO优于多个数据集上的几种方法。
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