The number of international benchmarking competitions is steadily increasing in various fields of machine learning (ML) research and practice. So far, however, little is known about the common practice as well as bottlenecks faced by the community in tackling the research questions posed. To shed light on the status quo of algorithm development in the specific field of biomedical imaging analysis, we designed an international survey that was issued to all participants of challenges conducted in conjunction with the IEEE ISBI 2021 and MICCAI 2021 conferences (80 competitions in total). The survey covered participants' expertise and working environments, their chosen strategies, as well as algorithm characteristics. A median of 72% challenge participants took part in the survey. According to our results, knowledge exchange was the primary incentive (70%) for participation, while the reception of prize money played only a minor role (16%). While a median of 80 working hours was spent on method development, a large portion of participants stated that they did not have enough time for method development (32%). 25% perceived the infrastructure to be a bottleneck. Overall, 94% of all solutions were deep learning-based. Of these, 84% were based on standard architectures. 43% of the respondents reported that the data samples (e.g., images) were too large to be processed at once. This was most commonly addressed by patch-based training (69%), downsampling (37%), and solving 3D analysis tasks as a series of 2D tasks. K-fold cross-validation on the training set was performed by only 37% of the participants and only 50% of the participants performed ensembling based on multiple identical models (61%) or heterogeneous models (39%). 48% of the respondents applied postprocessing steps.
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近年来,在自学学习(SSL)方面取得了重大成功,这有助于各种下游任务。但是,攻击者可能会窃取此类SSL模型并将其商业化以获利,这对于保护其知识产权(IP)至关重要。大多数现有的IP保护解决方案都是为监督学习模型而设计的,不能直接使用,因为它们要求模型的下游任务和目标标签在水印嵌入过程中已知并获得,这在SSL的域中并非总是可以的。为了解决此类问题,尤其是在水印嵌入过程中下游任务多样化且未知时,我们提出了一种新型的黑盒水印解决方案,名为SSL-WM,以保护SSL模型的所有权。 SSL-WM将水印编码器的水印输入映射到不变的表示空间中,该空间会导致任何下游分类器产生预期的行为,从而允许检测到嵌入式水印。我们使用不同的SSL模型(包括基于对比度和基于生成的生成型)来评估许多任务,例如计算机视觉(CV)和自然语言处理(NLP)等许多任务。实验结果表明,SSL-WM可以有效地验证各种下游任务中被盗SSL模型的所有权。此外,SSL-WM对模型进行微调和修剪攻击非常强大。最后,SSL-WM还可以从评估的水印检测方法中逃避检测,从而证明了其在保护SSL模型IP时的有希望的应用。
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交叉路口是自动驾驶任务最具挑战性的场景之一。由于复杂性和随机性,在相交处的基本应用(例如行为建模,运动预测,安全验证等)在很大程度上取决于数据驱动的技术。因此,交叉点中对流量参与者(TPS)的轨迹数据集的需求很大。目前,城市地区的大多数交叉路口都配备了交通信号灯。但是,尚无用于信号交叉点的大规模,高质量,公开可用的轨迹数据集。因此,在本文中,在中国天津选择了典型的两相信号交叉点。此外,管道旨在构建信号交叉数据集(SIND),其中包含7个小时的记录,其中包括13,000多种TPS,具有7种类型。然后,记录了信德的交通违规行为。此外,也将信德与其他类似作品进行比较。 SIND的特征可以概括如下:1)信德提供了更全面的信息,包括交通信号灯状态,运动参数,高清(HD)地图等。2)TPS的类别是多种多样和特征的,其中比例是脆弱的道路使用者(VRU)最高为62.6%3)显示了多次交通信号灯违反非电动车辆的行为。我们认为,Sind将是对现有数据集的有效补充,可以促进有关自动驾驶的相关研究。该数据集可通过以下方式在线获得:https://github.com/sotif-avlab/sind
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随着深度神经网络(DNN)的广泛应用,后门攻击逐渐引起了人们的关注。后门攻击是阴险的,中毒模型在良性样本上的表现良好,只有在给定特定输入时才会触发,这会导致神经网络产生不正确的输出。最先进的后门攻击工作是通过数据中毒(即攻击者注入中毒样品中的数据集中)实施的,并且用该数据集训练的模型被后门感染。但是,当前研究中使用的大多数触发因素都是在一小部分图像上修补的固定图案,并且经常被明显错误地标记,这很容易被人类或防御方法(例如神经清洁和前哨)检测到。同样,DNN很难在没有标记的情况下学习,因为它们可能会忽略小图案。在本文中,我们提出了一种基于频域的广义后门攻击方法,该方法可以实现后门植入而不会错标和访问训练过程。它是人类看不见的,能够逃避常用的防御方法。我们在三个数据集(CIFAR-10,STL-10和GTSRB)的无标签和清洁标签案例中评估了我们的方法。结果表明,我们的方法可以在所有任务上实现高攻击成功率(高于90%),而不会在主要任务上进行大量绩效降解。此外,我们评估了我们的方法的旁路性能,以进行各种防御措施,包括检测训练数据(即激活聚类),输入的预处理(即过滤),检测输入(即Sentinet)和检测模型(即神经清洁)。实验结果表明,我们的方法对这种防御能力表现出极好的鲁棒性。
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Recently, contrastive learning attracts increasing interests in neural text generation as a new solution to alleviate the exposure bias problem. It introduces a sequence-level training signal which is crucial to generation tasks that always rely on auto-regressive decoding. However, previous methods using contrastive learning in neural text generation usually lead to inferior performance. In this paper, we analyse the underlying reasons and propose a new Contrastive Neural Text generation framework, CoNT. CoNT addresses bottlenecks that prevent contrastive learning from being widely adopted in generation tasks from three aspects -- the construction of contrastive examples, the choice of the contrastive loss, and the strategy in decoding. We validate CoNT on five generation tasks with ten benchmarks, including machine translation, summarization, code comment generation, data-to-text generation and commonsense generation. Experimental results show that CoNT clearly outperforms the conventional training framework on all the ten benchmarks with a convincing margin. Especially, CoNT surpasses previous the most competitive contrastive learning method for text generation, by 1.50 BLEU on machine translation and 1.77 ROUGE-1 on summarization, respectively. It achieves new state-of-the-art on summarization, code comment generation (without external data) and data-to-text generation.
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对象视觉导航旨在基于代理的视觉观察来转向目标对象。非常希望合理地感知环境并准确控制代理。在导航任务中,我们引入了一个以代理为中心的关系图(ACRG),用于基于环境中的关系学习视觉表示。 ACRG是一种高效且合理的结构,包括两个关系,即物体之间的关系以及代理与目标之间的关系。一方面,我们设计了存储物体之间的相对水平位置的对象水平关系图(OHRG)。请注意,垂直关系不涉及OHRG,我们认为OHRG适合控制策略。另一方面,我们提出了代理 - 目标深度关系图(ATDRG),使代理能够将距离视为目标的距离。为了实现ATDRG,我们利用图像深度来表示距离。鉴于上述关系,代理可以察觉到环境和输出导航操作。鉴于ACRG和位置编码的全局功能构造的可视表示,代理可以捕获目标位置以执行导航操作。人工环境中的实验结果AI2-Thor表明ACRG显着优于看不见的检测环境中的其他最先进的方法。
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最近,变压器架构已经证明了其在自然语言处理(NLP)和计算机视觉(CV)任务中的重要性。虽然已知其他网络模型容易受到后门攻击的影响,但是在模型中嵌入触发器并在呈现触发器时控制模型行为,众所周知,这种攻击是否仍然在变压器模型上仍然有效,如果是的话,是否有效它可以以更具成本效益的方式完成。在本文中,我们提出DBIA,一种对CV导向的变压器网络的一种新型无数据响应攻击,利用变压器的固有注意机制来产生触发器并使用中毒代理数据集注入后门。我们在两个主流图像分类任务中基于三个基准变压器,即Vit,Deit和Swin变压器进行了广泛的实验..,Cifar10和ImageNet。评估结果表明,消耗较少的资源,我们的方法可以嵌入高层的成功率和对受害者变压器性能的低影响。我们的代码可在https://anonmous.4open.science/r/dbia-825d获得。
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The development of social media user stance detection and bot detection methods rely heavily on large-scale and high-quality benchmarks. However, in addition to low annotation quality, existing benchmarks generally have incomplete user relationships, suppressing graph-based account detection research. To address these issues, we propose a Multi-Relational Graph-Based Twitter Account Detection Benchmark (MGTAB), the first standardized graph-based benchmark for account detection. To our knowledge, MGTAB was built based on the largest original data in the field, with over 1.55 million users and 130 million tweets. MGTAB contains 10,199 expert-annotated users and 7 types of relationships, ensuring high-quality annotation and diversified relations. In MGTAB, we extracted the 20 user property features with the greatest information gain and user tweet features as the user features. In addition, we performed a thorough evaluation of MGTAB and other public datasets. Our experiments found that graph-based approaches are generally more effective than feature-based approaches and perform better when introducing multiple relations. By analyzing experiment results, we identify effective approaches for account detection and provide potential future research directions in this field. Our benchmark and standardized evaluation procedures are freely available at: https://github.com/GraphDetec/MGTAB.
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Different people speak with diverse personalized speaking styles. Although existing one-shot talking head methods have made significant progress in lip sync, natural facial expressions, and stable head motions, they still cannot generate diverse speaking styles in the final talking head videos. To tackle this problem, we propose a one-shot style-controllable talking face generation framework. In a nutshell, we aim to attain a speaking style from an arbitrary reference speaking video and then drive the one-shot portrait to speak with the reference speaking style and another piece of audio. Specifically, we first develop a style encoder to extract dynamic facial motion patterns of a style reference video and then encode them into a style code. Afterward, we introduce a style-controllable decoder to synthesize stylized facial animations from the speech content and style code. In order to integrate the reference speaking style into generated videos, we design a style-aware adaptive transformer, which enables the encoded style code to adjust the weights of the feed-forward layers accordingly. Thanks to the style-aware adaptation mechanism, the reference speaking style can be better embedded into synthesized videos during decoding. Extensive experiments demonstrate that our method is capable of generating talking head videos with diverse speaking styles from only one portrait image and an audio clip while achieving authentic visual effects. Project Page: https://github.com/FuxiVirtualHuman/styletalk.
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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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