Digital Twin is an emerging technology that replicates real-world entities into a digital space. It has attracted increasing attention in the transportation field and many researchers are exploring its future applications in the development of Intelligent Transportation System (ITS) technologies. Connected vehicles (CVs) and pedestrians are among the major traffic participants in ITS. However, the usage of Digital Twin in research involving both CV and pedestrian remains largely unexplored. In this study, a Digital Twin framework for CV and pedestrian in-the-loop simulation is proposed. The proposed framework consists of the physical world, the digital world, and data transmission in between. The features for the entities (CV and pedestrian) that need digital twined are divided into external state and internal state, and the attributes in each state are described. We also demonstrate a sample architecture under the proposed Digital Twin framework, which is based on Carla-Sumo Co-simulation and Cave automatic virtual environment (CAVE). The proposed framework is expected to provide guidance to the future Digital Twin research, and the architecture we build can serve as the testbed for further research and development of ITS applications on CV and pedestrian.
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哈希(Hashing)将项目数据投入二进制代码已显示出由于其储存量低和高查询速度而显示出跨模式检索的非凡人才。尽管在某些情况下取得了经验成功,但现有的跨模式散列方法通常不存在带有大量标记信息的数据时跨模式差距跨模式差距。为了避免以分裂和纠纷策略的激励,我们提出了深层的歧管散列(DMH),这是一种新颖的方法,是将半分配的无监督的交叉模式检索分为三个子问题,并建立一个简单而又简单而又又有一个简单的方法每个子问题的效率模型。具体而言,第一个模型是通过基于多种学习的半生数据补充的半生数据来构建的,用于获得模态不变的特征,而第二个模型和第三个模型旨在分别学习哈希码和哈希功能。在三个基准上进行的广泛实验表明,与最先进的完全配对和半成本无监督的跨模式散列方法相比,我们的DMH的优势。
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以安全为导向的研究思想和应用的开发需要精细的车辆轨迹数据,这些数据不仅具有很高的精度,而且还捕获了大量关键安全事件。本文介绍了Citysim数据集,该数据集的设计核心目的是促进基于安全的研究和应用。 Citysim的车辆轨迹从在12个不同位置录制的1140分钟的无人机视频中提取。它涵盖了各种道路几何形状,包括高速公路基本段,编织段,高速公路合并/偏离段,信号交叉点,停止对照的交叉点以及没有符号/信号控制的交叉点。通过五步操作生成CitySim轨迹,以确保轨迹精度。此外,数据集提供了车辆旋转的边界框信息,该信息被证明可以改善安全评估。与其他基于视频的轨迹数据集相比,CitySim数据集的严重性更高,包括切入,合并和分歧事件,其严重性更高。此外,CitySim通过提供相关资产(如记录位置的3D基本地图和信号时间)来促进对数字双胞胎应用的研究。这些功能为安全研究和应用程序提供了更全面的条件,例如自动驾驶汽车安全和基于位置的安全分析。该数据集可在https://github.com/ozheng1993/ucf-sst-citysim-dataset上在线获得。
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最近,机器学习(ML)电位的发展使得以量子力学(QM)模型的精度进行大规模和长期分子模拟成为可能。但是,对于高水平的QM方法,例如在元gga级和/或具有精确交换的密度函数理论(DFT),量子蒙特卡洛等,生成足够数量的用于训练的数据由于其高成本,计算挑战性。在这项工作中,我们证明了基于ML的DFT模型Deep Kohn-Sham(Deepks)可以在很大程度上缓解这个问题。 DeepKS采用计算高效的基于神经网络的功能模型来构建在廉价DFT模型上添加的校正项。在训练后,DeepKs提供了与高级QM方法相比,具有紧密匹配的能量和力,但是所需的训练数据的数量是比训练可靠的ML潜力所需的数量级要小。因此,DeepKs可以用作昂贵的QM型号和ML电位之间的桥梁:一个人可以生成相当数量的高准确性QM数据来训练DeepKs模型,然后使用DeepKs型号来标记大量的配置以标记训练ML潜力。该周期系统方案在DFT软件包算盘中实施,该计划是开源的,可以在各种应用程序中使用。
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Robot navigation in dynamic environments shared with humans is an important but challenging task, which suffers from performance deterioration as the crowd grows. In this paper, multi-subgoal robot navigation approach based on deep reinforcement learning is proposed, which can reason about more comprehensive relationships among all agents (robot and humans). Specifically, the next position point is planned for the robot by introducing history information and interactions in our work. Firstly, based on subgraph network, the history information of all agents is aggregated before encoding interactions through a graph neural network, so as to improve the ability of the robot to anticipate the future scenarios implicitly. Further consideration, in order to reduce the probability of unreliable next position points, the selection module is designed after policy network in the reinforcement learning framework. In addition, the next position point generated from the selection module satisfied the task requirements better than that obtained directly from the policy network. The experiments demonstrate that our approach outperforms state-of-the-art approaches in terms of both success rate and collision rate, especially in crowded human environments.
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在端到端RNN-TransDucer(RNN-T)中使用外部语言模型(ELM)使用仅文本数据进行语音识别是具有挑战性的。最近,已经开发了一类方法,例如密度比(DR)和内部语言模型估计(ILME),表现优于经典的浅融合(SF)方法。这些方法背后的基本思想是,RNN-T后验应首先先于隐式学习的内部语言模型(ILM),以便整合ELM。尽管最近的研究表明RNN-T仅学习一些低阶语言模型信息,但DR方法使用具有完整背景的训练有素的神经语言模型,这可能不适合估计ILM并恶化整合性能。基于DR方法,我们通过用低阶弱语言模型代替估计来提出低阶密度比方法(LODR)。在英语librispeech&tedlium-2和中国wenetspeech和aishell-1数据集的内域和跨域情景上进行了广泛的经验实验。结果表明,在大多数测试中,LODR在所有任务中始终胜过所有任务,而通常接近ILME,并且比DR更好。
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已知历史和未来的上下文信息对于准确的声学建模很重要。但是,获取未来的上下文会带来流式ASR的延迟。在本文中,我们提出了一个新的框架 - 块,模拟未来的上下文和解码(Cuside)以进行流语言识别。引入了一个新的仿真模块,以递归地模拟未来的上下文帧,而无需等待未来的上下文。使用自我监督的损失与ASR模型共同训练模拟模块;ASR模型通过通常的ASR损失(例如我们实验中使用的CTC-CRF)进行了优化。实验表明,与使用真实的未来框架作为正确的上下文相比,使用模拟的未来上下文可以大大降低延迟,同时保持识别精度。使用Cuside,我们在Aishell-1数据集上获得了新的最新流媒体ASR结果。
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Masked image modeling (MIM) performs strongly in pre-training large vision Transformers (ViTs). However, small models that are critical for real-world applications cannot or only marginally benefit from this pre-training approach. In this paper, we explore distillation techniques to transfer the success of large MIM-based pre-trained models to smaller ones. We systematically study different options in the distillation framework, including distilling targets, losses, input, network regularization, sequential distillation, etc, revealing that: 1) Distilling token relations is more effective than CLS token- and feature-based distillation; 2) An intermediate layer of the teacher network as target perform better than that using the last layer when the depth of the student mismatches that of the teacher; 3) Weak regularization is preferred; etc. With these findings, we achieve significant fine-tuning accuracy improvements over the scratch MIM pre-training on ImageNet-1K classification, using all the ViT-Tiny, ViT-Small, and ViT-base models, with +4.2%/+2.4%/+1.4% gains, respectively. Our TinyMIM model of base size achieves 52.2 mIoU in AE20K semantic segmentation, which is +4.1 higher than the MAE baseline. Our TinyMIM model of tiny size achieves 79.6% top-1 accuracy on ImageNet-1K image classification, which sets a new record for small vision models of the same size and computation budget. This strong performance suggests an alternative way for developing small vision Transformer models, that is, by exploring better training methods rather than introducing inductive biases into architectures as in most previous works. Code is available at https://github.com/OliverRensu/TinyMIM.
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Dataset distillation has emerged as a prominent technique to improve data efficiency when training machine learning models. It encapsulates the knowledge from a large dataset into a smaller synthetic dataset. A model trained on this smaller distilled dataset can attain comparable performance to a model trained on the original training dataset. However, the existing dataset distillation techniques mainly aim at achieving the best trade-off between resource usage efficiency and model utility. The security risks stemming from them have not been explored. This study performs the first backdoor attack against the models trained on the data distilled by dataset distillation models in the image domain. Concretely, we inject triggers into the synthetic data during the distillation procedure rather than during the model training stage, where all previous attacks are performed. We propose two types of backdoor attacks, namely NAIVEATTACK and DOORPING. NAIVEATTACK simply adds triggers to the raw data at the initial distillation phase, while DOORPING iteratively updates the triggers during the entire distillation procedure. We conduct extensive evaluations on multiple datasets, architectures, and dataset distillation techniques. Empirical evaluation shows that NAIVEATTACK achieves decent attack success rate (ASR) scores in some cases, while DOORPING reaches higher ASR scores (close to 1.0) in all cases. Furthermore, we conduct a comprehensive ablation study to analyze the factors that may affect the attack performance. Finally, we evaluate multiple defense mechanisms against our backdoor attacks and show that our attacks can practically circumvent these defense mechanisms.
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Benefiting from the intrinsic supervision information exploitation capability, contrastive learning has achieved promising performance in the field of deep graph clustering recently. However, we observe that two drawbacks of the positive and negative sample construction mechanisms limit the performance of existing algorithms from further improvement. 1) The quality of positive samples heavily depends on the carefully designed data augmentations, while inappropriate data augmentations would easily lead to the semantic drift and indiscriminative positive samples. 2) The constructed negative samples are not reliable for ignoring important clustering information. To solve these problems, we propose a Cluster-guided Contrastive deep Graph Clustering network (CCGC) by mining the intrinsic supervision information in the high-confidence clustering results. Specifically, instead of conducting complex node or edge perturbation, we construct two views of the graph by designing special Siamese encoders whose weights are not shared between the sibling sub-networks. Then, guided by the high-confidence clustering information, we carefully select and construct the positive samples from the same high-confidence cluster in two views. Moreover, to construct semantic meaningful negative sample pairs, we regard the centers of different high-confidence clusters as negative samples, thus improving the discriminative capability and reliability of the constructed sample pairs. Lastly, we design an objective function to pull close the samples from the same cluster while pushing away those from other clusters by maximizing and minimizing the cross-view cosine similarity between positive and negative samples. Extensive experimental results on six datasets demonstrate the effectiveness of CCGC compared with the existing state-of-the-art algorithms.
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