Safety comes first in many real-world applications involving autonomous agents. Despite a large number of reinforcement learning (RL) methods focusing on safety-critical tasks, there is still a lack of high-quality evaluation of those algorithms that adheres to safety constraints at each decision step under complex and unknown dynamics. In this paper, we revisit prior work in this scope from the perspective of state-wise safe RL and categorize them as projection-based, recovery-based, and optimization-based approaches, respectively. Furthermore, we propose Unrolling Safety Layer (USL), a joint method that combines safety optimization and safety projection. This novel technique explicitly enforces hard constraints via the deep unrolling architecture and enjoys structural advantages in navigating the trade-off between reward improvement and constraint satisfaction. To facilitate further research in this area, we reproduce related algorithms in a unified pipeline and incorporate them into SafeRL-Kit, a toolkit that provides off-the-shelf interfaces and evaluation utilities for safety-critical tasks. We then perform a comparative study of the involved algorithms on six benchmarks ranging from robotic control to autonomous driving. The empirical results provide an insight into their applicability and robustness in learning zero-cost-return policies without task-dependent handcrafting. The project page is available at https://sites.google.com/view/saferlkit.
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This paper describes the submission of the RoyalFlush neural machine translation system for the WMT 2022 translation efficiency task. Unlike the commonly used autoregressive translation system, we adopted a two-stage translation paradigm called Hybrid Regression Translation (HRT) to combine the advantages of autoregressive and non-autoregressive translation. Specifically, HRT first autoregressively generates a discontinuous sequence (e.g., make a prediction every $k$ tokens, $k>1$) and then fills in all previously skipped tokens at once in a non-autoregressive manner. Thus, we can easily trade off the translation quality and speed by adjusting $k$. In addition, by integrating other modeling techniques (e.g., sequence-level knowledge distillation and deep-encoder-shallow-decoder layer allocation strategy) and a mass of engineering efforts, HRT improves 80\% inference speed and achieves equivalent translation performance with the same-capacity AT counterpart. Our fastest system reaches 6k+ words/second on the GPU latency setting, estimated to be about 3.1x faster than the last year's winner.
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Recently, webly supervised learning (WSL) has been studied to leverage numerous and accessible data from the Internet. Most existing methods focus on learning noise-robust models from web images while neglecting the performance drop caused by the differences between web domain and real-world domain. However, only by tackling the performance gap above can we fully exploit the practical value of web datasets. To this end, we propose a Few-shot guided Prototypical (FoPro) representation learning method, which only needs a few labeled examples from reality and can significantly improve the performance in the real-world domain. Specifically, we initialize each class center with few-shot real-world data as the ``realistic" prototype. Then, the intra-class distance between web instances and ``realistic" prototypes is narrowed by contrastive learning. Finally, we measure image-prototype distance with a learnable metric. Prototypes are polished by adjacent high-quality web images and involved in removing distant out-of-distribution samples. In experiments, FoPro is trained on web datasets with a few real-world examples guided and evaluated on real-world datasets. Our method achieves the state-of-the-art performance on three fine-grained datasets and two large-scale datasets. Compared with existing WSL methods under the same few-shot settings, FoPro still excels in real-world generalization. Code is available at https://github.com/yuleiqin/fopro.
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安全加强学习(RL)在对风险敏感的任务上取得了重大成功,并在自主驾驶方面也表现出了希望(AD)。考虑到这个社区的独特性,对于安全广告而言,仍然缺乏高效且可再现的基线。在本文中,我们将SAFERL-KIT释放到基准的安全RL方法,以实现倾向的任务。具体而言,SAFERL-KIT包含了针对零构成的侵略任务的几种最新算法,包括安全层,恢复RL,非政策Lagrangian方法和可行的Actor-Critic。除了现有方法外,我们还提出了一种名为精确惩罚优化(EPO)的新型一阶方法,并充分证明了其在安全AD中的能力。 SAFERL-KIT中的所有算法均在政策设置下实现(i),从而提高了样本效率并可以更好地利用过去的日志; (ii)具有统一的学习框架,为研究人员提供了现成的接口,以将其特定领域的知识纳入基本的安全RL方法中。最后,我们对上述算法进行了比较评估,并阐明了它们的安全自动驾驶功效。源代码可在\ href {https://github.com/zlr20/saferl_kit} {this https url}中获得。
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手写的数学表达式识别旨在自动生成来自给定图像的乳胶序列。目前,基于注意的编码器 - 解码器模型被广泛用于此任务。它们通常以左右(L2R)方式生成目标序列,留下左右(R2L)上下文未分发。在本文中,我们提出了一种基于聚合的双向互访网络(ABM),其包括一个共享编码器和两个并行逆解码器(L2R和R2L)组成。通过相互蒸馏增强了两个解码器,其涉及每个训练步骤的一对一知识转移,从而充分利用来自两个反向的互补信息。此外,为了处理各种规模的数学符号,提出了注意聚合模块(AAM)以有效地集成了多尺度覆盖关注。值得注意的是,在推理阶段,考虑到模型已经从两个反向方向学习知识,我们只使用L2R分支推断,保持原始参数大小和推断速度。广泛的实验表明,我们的拟议方法在2016年克罗欧2014年达到56.85%的识别准确性,52.92%,在克罗欧2019年的53.96%,没有数据增强和模型集合,大大优于最先进的方法。源代码可在补充材料中获得。
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交通预测在智能交通系统中很重要,有利于交通安全,但由于现实世界交通系统中的复杂和动态的时空依赖性,这是非常具有挑战性的。先前的方法使用预定义或学习的静态图来提取空间相关性。但是,基于静态图形的方法无法挖掘交通网络的演变。研究人员随后为每次切片生成动态图形以反映空间相关性的变化,但它们遵循独立建模的时空依赖性的范例,忽略了串行空间影响。在本文中,我们提出了一种新的基于跨时动态图形的深度学习模型,名为CDGNet,用于交通预测。该模型能够通过利用横行动态图来有效地捕获每个时切片和其历史时片之间的串联空间依赖性。同时,我们设计了稀疏横行动态图的浇注机制,符合现实世界中的稀疏空间相关性。此外,我们提出了一种新颖的编码器解码器架构,用于结合基于交叉时间动态图形的GCN,用于多步行量预测。三个现实世界公共交通数据集的实验结果表明CDGNET优于最先进的基线。我们还提供了一种定性研究来分析我们建筑的有效性。
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我们总结了使用巨大的自动语音识别(ASR)模型的大量努力的结果,该模型使用包含大约一百万小时音频的大型,多样的未标记数据集进行了预训练。我们发现,即使对于拥有数万个小时的标记数据的非常大的任务,预训练,自我培训和扩大模型大小的组合也大大提高了数据效率。特别是,在具有34K小时标记数据的ASR任务上,通过微调80亿个参数预先训练的构象异构体模型,我们可以匹配最先进的(SOTA)性能(SOTA)的性能,只有3%的培训数据和通过完整的训练集可以显着改善SOTA。我们还报告了从使用大型预训练和自我训练的模型来完成一系列下游任务所获得的普遍利益,这些任务涵盖了广泛的语音域,并涵盖了多个数据集大小的大小,包括在许多人中获得SOTA性能公共基准。此外,我们利用预先训练的网络的学会表示,在非ASR任务上实现SOTA结果。
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The growing interest in intelligent services and privacy protection for mobile devices has given rise to the widespread application of federated learning in Multi-access Edge Computing (MEC). Diverse user behaviors call for personalized services with heterogeneous Machine Learning (ML) models on different devices. Federated Multi-task Learning (FMTL) is proposed to train related but personalized ML models for different devices, whereas previous works suffer from excessive communication overhead during training and neglect the model heterogeneity among devices in MEC. Introducing knowledge distillation into FMTL can simultaneously enable efficient communication and model heterogeneity among clients, whereas existing methods rely on a public dataset, which is impractical in reality. To tackle this dilemma, Federated MultI-task Distillation for Multi-access Edge CompuTing (FedICT) is proposed. FedICT direct local-global knowledge aloof during bi-directional distillation processes between clients and the server, aiming to enable multi-task clients while alleviating client drift derived from divergent optimization directions of client-side local models. Specifically, FedICT includes Federated Prior Knowledge Distillation (FPKD) and Local Knowledge Adjustment (LKA). FPKD is proposed to reinforce the clients' fitting of local data by introducing prior knowledge of local data distributions. Moreover, LKA is proposed to correct the distillation loss of the server, making the transferred local knowledge better match the generalized representation. Experiments on three datasets show that FedICT significantly outperforms all compared benchmarks in various data heterogeneous and model architecture settings, achieving improved accuracy with less than 1.2% training communication overhead compared with FedAvg and no more than 75% training communication round compared with FedGKT.
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Most existing text-video retrieval methods focus on cross-modal matching between the visual content of offline videos and textual query sentences. However, in real scenarios, online videos are frequently accompanied by relevant text information such as titles, tags, and even subtitles, which can be utilized to match textual queries. This inspires us to generate associated captions from offline videos to help with existing text-video retrieval methods. To do so, we propose to use the zero-shot video captioner with knowledge of pre-trained web-scale models (e.g., CLIP and GPT-2) to generate captions for offline videos without any training. Given the captions, one question naturally arises: what can auxiliary captions do for text-video retrieval? In this paper, we present a novel framework Cap4Video, which makes use of captions from three aspects: i) Input data: The video and captions can form new video-caption pairs as data augmentation for training. ii) Feature interaction: We perform feature interaction between video and caption to yield enhanced video representations. iii) Output score: The Query-Caption matching branch can be complementary to the original Query-Video matching branch for text-video retrieval. We conduct thorough ablation studies to demonstrate the effectiveness of our method. Without any post-processing, our Cap4Video achieves state-of-the-art performance on MSR-VTT (51.4%), VATEX (66.6%), MSVD (51.8%), and DiDeMo (52.0%).
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While the rollout of the fifth-generation mobile network (5G) is underway across the globe with the intention to deliver 4K/8K UHD videos, Augmented Reality (AR), and Virtual Reality (VR) content to the mass amounts of users, the coverage and throughput are still one of the most significant issues, especially in the rural areas, where only 5G in the low-frequency band are being deployed. This called for a high-performance adaptive bitrate (ABR) algorithm that can maximize the user quality of experience given 5G network characteristics and data rate of UHD contents. Recently, many of the newly proposed ABR techniques were machine-learning based. Among that, Pensieve is one of the state-of-the-art techniques, which utilized reinforcement-learning to generate an ABR algorithm based on observation of past decision performance. By incorporating the context of the 5G network and UHD content, Pensieve has been optimized into Pensieve 5G. New QoE metrics that more accurately represent the QoE of UHD video streaming on the different types of devices were proposed and used to evaluate Pensieve 5G against other ABR techniques including the original Pensieve. The results from the simulation based on the real 5G Standalone (SA) network throughput shows that Pensieve 5G outperforms both conventional algorithms and Pensieve with the average QoE improvement of 8.8% and 14.2%, respectively. Additionally, Pensieve 5G also performed well on the commercial 5G NR-NR Dual Connectivity (NR-DC) Network, despite the training being done solely using the data from the 5G Standalone (SA) network.
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