Graph Neural Networks (GNNs) have shown satisfying performance on various graph learning tasks. To achieve better fitting capability, most GNNs are with a large number of parameters, which makes these GNNs computationally expensive. Therefore, it is difficult to deploy them onto edge devices with scarce computational resources, e.g., mobile phones and wearable smart devices. Knowledge Distillation (KD) is a common solution to compress GNNs, where a light-weighted model (i.e., the student model) is encouraged to mimic the behavior of a computationally expensive GNN (i.e., the teacher GNN model). Nevertheless, most existing GNN-based KD methods lack fairness consideration. As a consequence, the student model usually inherits and even exaggerates the bias from the teacher GNN. To handle such a problem, we take initial steps towards fair knowledge distillation for GNNs. Specifically, we first formulate a novel problem of fair knowledge distillation for GNN-based teacher-student frameworks. Then we propose a principled framework named RELIANT to mitigate the bias exhibited by the student model. Notably, the design of RELIANT is decoupled from any specific teacher and student model structures, and thus can be easily adapted to various GNN-based KD frameworks. We perform extensive experiments on multiple real-world datasets, which corroborates that RELIANT achieves less biased GNN knowledge distillation while maintaining high prediction utility.

Deep latent variable models have achieved significant empirical successes in model-based reinforcement learning (RL) due to their expressiveness in modeling complex transition dynamics. On the other hand, it remains unclear theoretically and empirically how latent variable models may facilitate learning, planning, and exploration to improve the sample efficiency of RL. In this paper, we provide a representation view of the latent variable models for state-action value functions, which allows both tractable variational learning algorithm and effective implementation of the optimism/pessimism principle in the face of uncertainty for exploration. In particular, we propose a computationally efficient planning algorithm with UCB exploration by incorporating kernel embeddings of latent variable models. Theoretically, we establish the sample complexity of the proposed approach in the online and offline settings. Empirically, we demonstrate superior performance over current state-of-the-art algorithms across various benchmarks.

Open world object detection aims at detecting objects that are absent in the object classes of the training data as unknown objects without explicit supervision. Furthermore, the exact classes of the unknown objects must be identified without catastrophic forgetting of the previous known classes when the corresponding annotations of unknown objects are given incrementally. In this paper, we propose a two-stage training approach named Open World DETR for open world object detection based on Deformable DETR. In the first stage, we pre-train a model on the current annotated data to detect objects from the current known classes, and concurrently train an additional binary classifier to classify predictions into foreground or background classes. This helps the model to build an unbiased feature representations that can facilitate the detection of unknown classes in subsequent process. In the second stage, we fine-tune the class-specific components of the model with a multi-view self-labeling strategy and a consistency constraint. Furthermore, we alleviate catastrophic forgetting when the annotations of the unknown classes becomes available incrementally by using knowledge distillation and exemplar replay. Experimental results on PASCAL VOC and MS-COCO show that our proposed method outperforms other state-of-the-art open world object detection methods by a large margin.

Achieving accurate and automated tumor segmentation plays an important role in both clinical practice and radiomics research. Segmentation in medicine is now often performed manually by experts, which is a laborious, expensive and error-prone task. Manual annotation relies heavily on the experience and knowledge of these experts. In addition, there is much intra- and interobserver variation. Therefore, it is of great significance to develop a method that can automatically segment tumor target regions. In this paper, we propose a deep learning segmentation method based on multimodal positron emission tomography-computed tomography (PET-CT), which combines the high sensitivity of PET and the precise anatomical information of CT. We design an improved spatial attention network(ISA-Net) to increase the accuracy of PET or CT in detecting tumors, which uses multi-scale convolution operation to extract feature information and can highlight the tumor region location information and suppress the non-tumor region location information. In addition, our network uses dual-channel inputs in the coding stage and fuses them in the decoding stage, which can take advantage of the differences and complementarities between PET and CT. We validated the proposed ISA-Net method on two clinical datasets, a soft tissue sarcoma(STS) and a head and neck tumor(HECKTOR) dataset, and compared with other attention methods for tumor segmentation. The DSC score of 0.8378 on STS dataset and 0.8076 on HECKTOR dataset show that ISA-Net method achieves better segmentation performance and has better generalization. Conclusions: The method proposed in this paper is based on multi-modal medical image tumor segmentation, which can effectively utilize the difference and complementarity of different modes. The method can also be applied to other multi-modal data or single-modal data by proper adjustment.

在本文中，我们设计了一个基于信息的多机器人来源，以寻求算法，其中一组移动传感器仅使用基于局部范围的测量值就本地化并移动靠近单个源。在算法中，移动传感器执行源标识/本地化以估计源位置；同时，他们移至新位置，以最大程度地提高有关传感器测量中包含的源的Fisher信息。在这样做的过程中，它们改善了源位置估计，并更靠近源。与传统的攀登算法相比，我们的算法在收敛速度方面具有优越性，在测量模型和信息指标的选择中是灵活的，并且对测量模型误差非常强大。此外，我们提供了算法的完全分布式版本，每个传感器都决定自己的动作，并且仅通过稀疏的通信网络与邻居共享信息。我们进行密集的仿真实验，以测试带有光传感器的小型地面车辆上的大规模系统和物理实验的算法，这表明在寻求光源方面取得了成功。

多臂强盗（MAB）问题是一个简单而强大的框架，在不确定性下的决策背景下进行了广泛的研究。在许多实际应用程序（例如机器人应用程序）中，选择ARM对应于限制下一个可用臂（动作）选择的物理动作。在此激励的情况下，我们研究了一个称为图形匪徒的mAb的扩展，在该图形上，试图从不同节点收集的奖励来传播图形。该图定义了代理在每个步骤中选择下一个可用节点时的自由度。我们假设图形结构完全可用，但是奖励分布未知。我们建立在基于脱机图的计划算法和乐观原则的基础上，我们设计了一种在线学习算法，该算法可以使用乐观原则来平衡长期探索 - 探索。我们表明我们提出的算法达到$ o（| s | \ sqrt {t} \ log（t）+d | s | s | \ log t）$学习后悔，其中$ | s | $是节点的数量和$ d $是该图的直径，与在类似设置下的最著名的增强学习算法相比，这是优越的。数值实验证实，我们的算法优于几个基准。最后，我们提出了一个由图形匪徒框架建模的合成机器人应用程序，其中机器人在农村/郊区位置网络上移动，使用我们建议的算法提供高速Internet访问。

病理学家需要结合不同染色病理切片的信息，以获得准确的诊断结果。可变形图像配准是融合多模式病理切片的必要技术。本文提出了一个基于混合特征的基于特征的可变形图像登记框架，用于染色的病理样品。我们首先提取密集的特征点，并通过两个深度学习功能网络执行匹配点。然后，为了进一步减少虚假匹配，提出了一种结合隔离森林统计模型和局部仿射校正模型的异常检测方法。最后，插值方法基于上述匹配点生成用于病理图像注册的DVF。我们在非刚性组织学图像注册（ANHIR）挑战的数据集上评估了我们的方法，该挑战与IEEE ISBI 2019会议共同组织。我们的技术的表现使传统方法的平均水平注册目标误差（RTRE）达到0.0034。所提出的方法实现了最先进的性能，并在评估测试数据集时将其排名1。提出的基于特征的混合特征的注册方法可能会成为病理图像注册的可靠方法。

本文研究了用于多机构增强学习的政策优化算法。我们首先在全信息设置中提出了针对两人零和零和马尔可夫游戏的算法框架，其中每次迭代均使用一个策略更新，使用某个矩阵游戏算法在每个状态下进行策略更新，并带有一个带有特定的值更新步骤学习率。该框架统一了许多现有和新的政策优化算法。我们表明，只要矩阵游戏算法在每种状态下，该算法的州平均策略会收敛到游戏的近似NASH平衡（NE），只要矩阵游戏算法在每个状态下都具有低称重的遗憾价值更新。接下来，我们证明，该框架与每个状态（和平滑值更新）的乐观跟踪定制领导者（oftrl）算法可以找到$ \ Mathcal {\ widetilde {o}}（t^{ - 5 /6}）$ t $迭代中的$近似NE，并且具有稍微修改的值更新规则的类似算法可实现更快的$ \ Mathcal {\ widetilde {o}}}}（t^{ - 1}）$收敛率。这些改进了当前最佳$ \ Mathcal {\ widetilde {o}}}（t^{ - 1/2}）$对称策略优化类型算法的速率。我们还将此算法扩展到多玩家通用-SUM Markov游戏，并显示$ \ MATHCAL {\ widetilde {o}}}（t^{ - 3/4}）$收敛率与粗相关均衡（CCE）。最后，我们提供了一个数值示例来验证我们的理论并研究平滑价值更新的重要性，并发现使用“渴望”的价值更新（等同于独立的自然策略梯度算法）也可能会大大减慢收敛性，即使在$ h = 2 $层的简单游戏。

图表学习目的旨在将节点内容与图形结构集成以学习节点/图表示。然而，发现许多现有的图形学习方法在具有高异性级别的数据上不能很好地工作，这是不同类标签之间很大比例的边缘。解决这个问题的最新努力集中在改善消息传递机制上。但是，尚不清楚异质性是否确实会损害图神经网络（GNNS）的性能。关键是要展现一个节点与其直接邻居之间的关系，例如它们是异性还是同质性？从这个角度来看，我们在这里研究了杂质表示在披露连接节点之间的关系之前/之后的杂音表示的作用。特别是，我们提出了一个端到端框架，该框架既学习边缘的类型（即异性/同质性），并利用边缘类型的信息来提高图形神经网络的表现力。我们以两种不同的方式实施此框架。具体而言，为了避免通过异质边缘传递的消息，我们可以通过删除边缘分类器鉴定的异性边缘来优化图形结构。另外，可以利用有关异性邻居的存在的信息进行特征学习，因此，设计了一种混合消息传递方法来汇总同质性邻居，并根据边缘分类使异性邻居多样化。广泛的实验表明，在整个同质级别的多个数据集上，通过在多个数据集上提出的框架对GNN的绩效提高了显着提高。

我们考虑通过连接到中央服务器的一组边缘设备的大规模分布式优化，其中服务器和边缘设备之间的有限通信带宽对优化过程提出了显着的瓶颈。灵感来自最近在联邦学习的进步，我们提出了一种分布式随机梯度下降（SGD）类型算法，该算法利用梯度的稀疏性，尽可能降低沟通负担。在算法的核心，用于使用压缩的感测技术来压缩器件侧的局部随机梯度;在服务器端，从嘈杂的聚合压缩的本地梯度恢复全局随机梯度的稀疏近似。我们对通信信道产生的噪声扰动的存在，对我们算法的收敛性进行了理论分析，并且还进行了数值实验以证实其有效性。