基于时空的图(STMAP)方法显示出为车辆轨迹重建处理高角度视频的巨大潜力,可以满足各种数据驱动的建模和模仿学习应用的需求。在本文中,我们开发了时空深嵌入(STDE)模型,该模型在像素和实例水平上施加了平等约束,以生成用于STMAP上车辆条纹分割的实例感知嵌入。在像素级别上,每个像素在不同范围的8-邻居像素进行编码,随后使用该编码来指导神经网络学习嵌入机制。在实例级别上,歧视性损耗函数被设计为将属于同一实例的像素更接近,并将不同实例的平均值分开。然后,通过静脉 - 沃特算法算法优化时空亲和力的输出,以获得最终的聚类结果。基于分割指标,我们的模型优于其他五个用于STMAP处理的基线,并在阴影,静态噪声和重叠的影响下显示出稳健性。该设计的模型用于处理所有公共NGSIM US-101视频,以生成完整的车辆轨迹,表明具有良好的可扩展性和适应性。最后但并非最不重要的一点是,讨论了带有STDE和未来方向的扫描线方法的优势。代码,STMAP数据集和视频轨迹在在线存储库中公开可用。 github链接:shorturl.at/jklt0。
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从广泛的流量监视传感器收集的旅行时间数据需要大数据分析工具来查询,可视化和识别有意义的流量模式。本文利用了Caltrans性能测量系统(PEMS)系统的大规模旅行时间数据集,该系统是传统数据处理和建模工具的溢出。为了克服大量数据的挑战,大数据分析引擎Apache Spark和Apache MXNET用于数据争吵和建模。进行季节性和自相关以探索和可视化时变数据的趋势。受到许多人工智能(AI)任务的层次结构成功的启发,我们巩固了细胞和隐藏状态,从低级到高级LSTM传递,其注意力集中在类似于人类感知系统的运作方式上。设计的分层LSTM模型可以在不同的时间尺度上考虑依赖项,以捕获网络级别旅行时间的时空相关性。然后,设计了另一个自我发场模块,以将LSTM提取的功能连接到完全连接的层,从而预测所有走廊的旅行时间,而不是单个链接/路线。比较结果表明,层次的LSTM引起注意(HIERLSTMAT)模型在30分钟和45分钟的视野时给出了最佳的预测结果,并且可以成功预测不寻常的拥塞。通过将它们与流行的数据科学和深度学习框架进行比较,从大数据分析工具中得出的效率得到了评估。
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在本文中,我们使用两个无监督的学习算法的组合介绍了路边激光雷达物体检测的解决方案。 3D点云数据首先将球形坐标转换成球形坐标并使用散列函数填充到方位角网格矩阵中。之后,RAW LIDAR数据被重新排列成空间 - 时间数据结构,以存储范围,方位角和强度的信息。基于强度信道模式识别,应用动态模式分解方法将点云数据分解成低级背景和稀疏前景。三角算法根据范围信息,自动发现分割值以将移动目标与静态背景分开。在强度和范围背景减法之后,将使用基于密度的检测器检测到前景移动物体,并编码到状态空间模型中以进行跟踪。所提出的模型的输出包括车辆轨迹,可以实现许多移动性和安全应用。该方法针对商业流量数据收集平台进行了验证,并证明了对基础设施激光雷达对象检测的高效可靠的解决方案。与之前的方法相比,该方法直接处理散射和离散点云,所提出的方法可以建立3D测量数据的复杂线性关系较小,这捕获了我们经常需要的空间时间结构。
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本文提出了一种机器学习增强的纵向扫描线方法,用于从大角度交通摄像机中提取车辆轨迹。通过将空间颞映射(STMAP)分解到稀疏前景和低秩背景,应用动态模式分解(DMD)方法来提取车辆股线。通过调整两个普遍的深度学习架构,设计了一个名为Res-Unet +的深神经网络。 RES-UNET +神经网络显着提高了基于STMAP的车辆检测的性能,DMD模型提供了许多有趣的见解,了解由Stmap保留的潜在空间结构的演变。与先前的图像处理模型和主流语义分割深神经网络进行比较模型输出。经过彻底的评估后,证明该模型对许多具有挑战性的因素来说是准确和强大的。最后但并非最不重要的是,本文从根本上解决了NGSIM轨迹数据中发现了许多质量问题。清除清洁的高质量轨迹数据,以支持交通流量和微观车辆控制的未来理论和建模研究。该方法是用于基于视频的轨迹提取的可靠解决方案,并且具有广泛的适用性。
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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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In this paper, we propose a robust 3D detector, named Cross Modal Transformer (CMT), for end-to-end 3D multi-modal detection. Without explicit view transformation, CMT takes the image and point clouds tokens as inputs and directly outputs accurate 3D bounding boxes. The spatial alignment of multi-modal tokens is performed implicitly, by encoding the 3D points into multi-modal features. The core design of CMT is quite simple while its performance is impressive. CMT obtains 73.0% NDS on nuScenes benchmark. Moreover, CMT has a strong robustness even if the LiDAR is missing. Code will be released at https://github.com/junjie18/CMT.
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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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Blind image quality assessment (BIQA) remains challenging due to the diversity of distortion and image content variation, which complicate the distortion patterns crossing different scales and aggravate the difficulty of the regression problem for BIQA. However, existing BIQA methods often fail to consider multi-scale distortion patterns and image content, and little research has been done on learning strategies to make the regression model produce better performance. In this paper, we propose a simple yet effective Progressive Multi-Task Image Quality Assessment (PMT-IQA) model, which contains a multi-scale feature extraction module (MS) and a progressive multi-task learning module (PMT), to help the model learn complex distortion patterns and better optimize the regression issue to align with the law of human learning process from easy to hard. To verify the effectiveness of the proposed PMT-IQA model, we conduct experiments on four widely used public datasets, and the experimental results indicate that the performance of PMT-IQA is superior to the comparison approaches, and both MS and PMT modules improve the model's performance.
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Automatic music generation with artificial intelligence typically requires a large amount of data which is hard to obtain for many less common genres and musical instruments. To tackle this issue, we present ongoing work and preliminary findings on the possibility for deep models to transfer knowledge from language to music, by finetuning large language models pre-trained on a massive text corpus on only hundreds of MIDI files of drum performances. We show that by doing so, one of the largest, state-of-the-art models (GPT3) is capable of generating reasonable drum grooves, while models that are not pre-trained (Transformer) shows no such ability beyond naive repetition. Evaluating generated music is a challenging task, more so is evaluating drum grooves with little precedence in literature. Hence, we propose a tailored structural evaluation method and analyze drum grooves produced by GPT3 compared to those played by human professionals, exposing the strengths and weaknesses of such generation by language-to-music transfer. Our findings suggest that language-to-music transfer learning with large language models is viable and promising.
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Few Shot Instance Segmentation (FSIS) requires models to detect and segment novel classes with limited several support examples. In this work, we explore a simple yet unified solution for FSIS as well as its incremental variants, and introduce a new framework named Reference Twice (RefT) to fully explore the relationship between support/query features based on a Transformer-like framework. Our key insights are two folds: Firstly, with the aid of support masks, we can generate dynamic class centers more appropriately to re-weight query features. Secondly, we find that support object queries have already encoded key factors after base training. In this way, the query features can be enhanced twice from two aspects, i.e., feature-level and instance-level. In particular, we firstly design a mask-based dynamic weighting module to enhance support features and then propose to link object queries for better calibration via cross-attention. After the above steps, the novel classes can be improved significantly over our strong baseline. Additionally, our new framework can be easily extended to incremental FSIS with minor modification. When benchmarking results on the COCO dataset for FSIS, gFSIS, and iFSIS settings, our method achieves a competitive performance compared to existing approaches across different shots, e.g., we boost nAP by noticeable +8.2/+9.4 over the current state-of-the-art FSIS method for 10/30-shot. We further demonstrate the superiority of our approach on Few Shot Object Detection. Code and model will be available.
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