Point cloud registration (PCR) is a popular research topic in computer vision. Recently, the registration method in an evolutionary way has received continuous attention because of its robustness to the initial pose and flexibility in objective function design. However, most evolving registration methods cannot tackle the local optimum well and they have rarely investigated the success ratio, which implies the probability of not falling into local optima and is closely related to the practicality of the algorithm. Evolutionary multi-task optimization (EMTO) is a widely used paradigm, which can boost exploration capability through knowledge transfer among related tasks. Inspired by this concept, this study proposes a novel evolving registration algorithm via EMTO, where the multi-task configuration is based on the idea of solution space cutting. Concretely, one task searching in cut space assists another task with complex function landscape in escaping from local optima and enhancing successful registration ratio. To reduce unnecessary computational cost, a sparse-to-dense strategy is proposed. In addition, a novel fitness function robust to various overlap rates as well as a problem-specific metric of computational cost is introduced. Compared with 7 evolving registration approaches and 4 traditional registration approaches on the object-scale and scene-scale registration datasets, experimental results demonstrate that the proposed method has superior performances in terms of precision and tackling local optima.

Current domain adaptation methods for face anti-spoofing leverage labeled source domain data and unlabeled target domain data to obtain a promising generalizable decision boundary. However, it is usually difficult for these methods to achieve a perfect domain-invariant liveness feature disentanglement, which may degrade the final classification performance by domain differences in illumination, face category, spoof type, etc. In this work, we tackle cross-scenario face anti-spoofing by proposing a novel domain adaptation method called cyclically disentangled feature translation network (CDFTN). Specifically, CDFTN generates pseudo-labeled samples that possess: 1) source domain-invariant liveness features and 2) target domain-specific content features, which are disentangled through domain adversarial training. A robust classifier is trained based on the synthetic pseudo-labeled images under the supervision of source domain labels. We further extend CDFTN for multi-target domain adaptation by leveraging data from more unlabeled target domains. Extensive experiments on several public datasets demonstrate that our proposed approach significantly outperforms the state of the art.

Knowledge Distillation (KD) transfers the knowledge from a high-capacity teacher model to promote a smaller student model. Existing efforts guide the distillation by matching their prediction logits, feature embedding, etc., while leaving how to efficiently utilize them in junction less explored. In this paper, we propose Hint-dynamic Knowledge Distillation, dubbed HKD, which excavates the knowledge from the teacher' s hints in a dynamic scheme. The guidance effect from the knowledge hints usually varies in different instances and learning stages, which motivates us to customize a specific hint-learning manner for each instance adaptively. Specifically, a meta-weight network is introduced to generate the instance-wise weight coefficients about knowledge hints in the perception of the dynamical learning progress of the student model. We further present a weight ensembling strategy to eliminate the potential bias of coefficient estimation by exploiting the historical statics. Experiments on standard benchmarks of CIFAR-100 and Tiny-ImageNet manifest that the proposed HKD well boost the effect of knowledge distillation tasks.

Over-parameterization of deep neural networks (DNNs) has shown high prediction accuracy for many applications. Although effective, the large number of parameters hinders its popularity on resource-limited devices and has an outsize environmental impact. Sparse training (using a fixed number of nonzero weights in each iteration) could significantly mitigate the training costs by reducing the model size. However, existing sparse training methods mainly use either random-based or greedy-based drop-and-grow strategies, resulting in local minimal and low accuracy. In this work, to assist explainable sparse training, we propose important weights Exploitation and coverage Exploration to characterize Dynamic Sparse Training (DST-EE), and provide quantitative analysis of these two metrics. We further design an acquisition function and provide the theoretical guarantees for the proposed method and clarify its convergence property. Experimental results show that sparse models (up to 98\% sparsity) obtained by our proposed method outperform the SOTA sparse training methods on a wide variety of deep learning tasks. On VGG-19 / CIFAR-100, ResNet-50 / CIFAR-10, ResNet-50 / CIFAR-100, our method has even higher accuracy than dense models. On ResNet-50 / ImageNet, the proposed method has up to 8.2\% accuracy improvement compared to SOTA sparse training methods.

Data-efficient learning on graphs (GEL) is essential in real-world applications. Existing GEL methods focus on learning useful representations for nodes, edges, or entire graphs with ``small'' labeled data. But the problem of data-efficient learning for subgraph prediction has not been explored. The challenges of this problem lie in the following aspects: 1) It is crucial for subgraphs to learn positional features to acquire structural information in the base graph in which they exist. Although the existing subgraph neural network method is capable of learning disentangled position encodings, the overall computational complexity is very high. 2) Prevailing graph augmentation methods for GEL, including rule-based, sample-based, adaptive, and automated methods, are not suitable for augmenting subgraphs because a subgraph contains fewer nodes but richer information such as position, neighbor, and structure. Subgraph augmentation is more susceptible to undesirable perturbations. 3) Only a small number of nodes in the base graph are contained in subgraphs, which leads to a potential ``bias'' problem that the subgraph representation learning is dominated by these ``hot'' nodes. By contrast, the remaining nodes fail to be fully learned, which reduces the generalization ability of subgraph representation learning. In this paper, we aim to address the challenges above and propose a Position-Aware Data-Efficient Learning framework for subgraph neural networks called PADEL. Specifically, we propose a novel node position encoding method that is anchor-free, and design a new generative subgraph augmentation method based on a diffused variational subgraph autoencoder, and we propose exploratory and exploitable views for subgraph contrastive learning. Extensive experiment results on three real-world datasets show the superiority of our proposed method over state-of-the-art baselines.

基于深度学习的水下图像增强（UIE）面临的主要挑战是地面真相高质量的图像是不可用的。大多数现有方法首先生成近似参考图，然后可以确定地训练增强网络。这种方法无法处理参考图的歧义。在本文中，我们将UIE解决为分布估计和共识过程。我们提出了一个新颖的概率网络，以了解退化的水下图像的增强分布。具体而言，我们将条件变异自动编码器与自适应实例归一化结合在一起，以构建增强分布。之后，我们采用共识过程来根据分布中的一组样本来预测确定性结果。通过学习增强分布，我们的方法可以在某种程度上应对参考图标记中引入的偏差。此外，共识过程对于捕获强大而稳定的结果很有用。我们在两个广泛使用的现实水下图像增强数据集上检查了提出的方法。实验结果表明，我们的方法可以对可能的增强预测进行抽样。同时，与最先进的UIE方法相比，共识估计会产生竞争性能。代码可在https://github.com/zhenqifu/puie-net上找到。

时空视频超分辨率（STVSR）的目标是提高帧速率（也称为时间分辨率）和给定视频的空间分辨率。最近的方法通过端到端的深神经网络解决了STVSR。一个流行的解决方案是首先提高视频的帧速率；然后在不同的框架功能之间执行特征改进；最后增加了这些功能的空间分辨率。在此过程中，仔细利用了不同帧的特征之间的时间相关性。然而，尚未强调不同（空间）分辨率的特征之间的空间相关性。在本文中，我们提出了一个时空特征交互网络，以通过在不同框架和空间分辨率的特征之间利用空间和时间相关来增强STVSR。具体而言，引入了空间 - 周期框架插值模块，以同时和互动性地插值低分辨率和高分辨率的中间框架特征。后来分别部署了空间 - 周期性的本地和全局细化模块，以利用不同特征之间的空间 - 周期相关性进行细化。最后，采用了新的运动一致性损失来增强重建帧之间的运动连续性。我们对三个标准基准测试，即VID4，Vimeo-90K和Adobe240进行实验，结果表明，我们的方法可以通过相当大的余量提高了最先进的方法。我们的代码将在https://github.com/yuezijie/stinet-pace time-video-super-resolution上找到。

知识蒸馏（KD）将知识从高容量的教师网络转移到加强较小的学生。现有方法着重于发掘知识的提示，并将整个知识转移给学生。但是，由于知识在不同的学习阶段显示出对学生的价值观，因此出现了知识冗余。在本文中，我们提出了知识冷凝蒸馏（KCD）。具体而言，每个样本上的知识价值是动态估计的，基于期望最大化（EM）框架的迭代性凝结，从老师那里划定了一个紧凑的知识，以指导学生学习。我们的方法很容易建立在现成的KD方法之上，没有额外的培训参数和可忽略不计的计算开销。因此，它为KD提出了一种新的观点，在该观点中，积极地识别教师知识的学生可以学会更有效，有效地学习。对标准基准测试的实验表明，提出的KCD可以很好地提高学生模型的性能，甚至更高的蒸馏效率。代码可在https://github.com/dzy3/kcd上找到。

图形离群值检测是一项具有许多应用程序的新兴但至关重要的机器学习任务。尽管近年来算法扩散，但缺乏标准和统一的绩效评估设置限制了它们在现实世界应用中的进步和使用。为了利用差距，我们（据我们所知）（据我们所知）第一个全面的无监督节点离群值检测基准为unod，并带有以下亮点：（1）评估骨架从经典矩阵分解到最新图形神经的骨架的14个方法网络； （2）在现实世界数据集上使用不同类型的注射异常值和自然异常值对方法性能进行基准测试； （3）通过在不同尺度的合成图上使用运行时和GPU存储器使用算法的效率和可扩展性。基于广泛的实验结果的分析，我们讨论了当前渠道方法的利弊，并指出了多个关键和有希望的未来研究方向。

强大的语义细分面临的一个普遍挑战是昂贵的数据注释成本。现有的半监督解决方案显示出解决此问题的巨大潜力。他们的关键想法是通过未经监督的数据增加未标记的数据来构建一致性正则化，以进行模型培训。未标记数据的扰动使一致性训练损失使半监督的语义分割受益。但是，这些扰动破坏了图像上下文并引入了不自然的边界，这对语义分割是有害的。此外，广泛采用的半监督学习框架，即均值老师，遭受了绩效限制，因为学生模型最终会收敛于教师模型。在本文中，首先，我们提出了一个友好的可区分几何扭曲，以进行无监督的数据增强。其次，提出了一个新颖的对抗双重学生框架，以从以下两个方面从以下两个方面改善均等老师：（1）双重学生模型是独立学习的，除了稳定约束以鼓励利用模型多样性； （2）对对抗性训练计划适用于学生，并诉诸歧视者以区分无标记数据的可靠伪标签进行自我训练。通过对Pascal VOC2012和CityScapes进行的广泛实验来验证有效性。我们的解决方案可显着提高两个数据集的性能和最先进的结果。值得注意的是，与完全监督相比，我们的解决方案仅使用Pascal VOC2012上的12.5％注释数据获得了73.4％的可比MIOU。我们的代码和模型可在https://github.com/caocong/ads-semiseg上找到。