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.

Neural networks are susceptible to data inference attacks such as the membership inference attack, the adversarial model inversion attack and the attribute inference attack, where the attacker could infer useful information such as the membership, the reconstruction or the sensitive attributes of a data sample from the confidence scores predicted by the target classifier. In this paper, we propose a method, namely PURIFIER, to defend against membership inference attacks. It transforms the confidence score vectors predicted by the target classifier and makes purified confidence scores indistinguishable in individual shape, statistical distribution and prediction label between members and non-members. The experimental results show that PURIFIER helps defend membership inference attacks with high effectiveness and efficiency, outperforming previous defense methods, and also incurs negligible utility loss. Besides, our further experiments show that PURIFIER is also effective in defending adversarial model inversion attacks and attribute inference attacks. For example, the inversion error is raised about 4+ times on the Facescrub530 classifier, and the attribute inference accuracy drops significantly when PURIFIER is deployed in our experiment.

Graph neural networks (GNNs) are popular weapons for modeling relational data. Existing GNNs are not specified for attribute-incomplete graphs, making missing attribute imputation a burning issue. Until recently, many works notice that GNNs are coupled with spectral concentration, which means the spectrum obtained by GNNs concentrates on a local part in spectral domain, e.g., low-frequency due to oversmoothing issue. As a consequence, GNNs may be seriously flawed for reconstructing graph attributes as graph spectral concentration tends to cause a low imputation precision. In this work, we present a regularized graph autoencoder for graph attribute imputation, named MEGAE, which aims at mitigating spectral concentration problem by maximizing the graph spectral entropy. Notably, we first present the method for estimating graph spectral entropy without the eigen-decomposition of Laplacian matrix and provide the theoretical upper error bound. A maximum entropy regularization then acts in the latent space, which directly increases the graph spectral entropy. Extensive experiments show that MEGAE outperforms all the other state-of-the-art imputation methods on a variety of benchmark datasets.

This paper introduces a structure-deformable land-air robot which possesses both excellent ground driving and flying ability, with smooth switching mechanism between two modes. The elaborate coupled dynamics model of the proposed robot is established, including rotors, chassis, especially the deformable structures. Furthermore, taking fusion locomotion and complex near-ground situations into consideration, a model based controller is designed for landing and mode switching under various harsh conditions, in which we realise the cooperation between fused two motion modes. The entire system is implemented in ADAMS/Simulink simulation and in practical. We conduct experiments under various complex scenarios. The results show our robot can accomplish land-air switching swiftly and smoothly, and the designed controller can effectively improve the landing flexibility and reliability.

在过去的十年中，AI AID毒品发现（AIDD）的计算方法和数据集策划的繁荣发展。但是，现实世界中的药物数据集经常表现出高度不平衡的分布，这在很大程度上被当前的文献忽略了，但可能会严重损害机器学习应用程序的公平性和概括。在这一观察结果的激励下，我们介绍了Imdrug，这是一个全面的基准标准，其开源python库由4个不平衡设置，11个AI-Ready数据集，54个学习任务和16种为不平衡学习量身定制的基线算法。它为涵盖广泛的药物发现管道（例如分子建模，药物靶标相互作用和逆合合成）的问题和解决方案提供了可访问且可定制的测试床。我们通过新的评估指标进行广泛的实证研究，以证明现有算法在数据不平衡情况下无法解决药物和药物挑战。我们认为，Imdrug为未来的研究和发展开辟了途径，在AIDD和深度不平衡学习的交集中对现实世界中的挑战开辟了道路。

知识图（kg）是近年来突出的知识表示形式。因为它集中在名义实体及其关系上，所以传统的知识图本质上是静态和百科全书。在此基础上，事件知识图（事件kg）通过文本处理对时间和空间动力进行建模，以促进下游应用程序，例如提问，建议和智能搜索。另一方面，现有的KG研究主要集中在文本处理和静态事实上，而忽略了照片，电影和预训练的神经网络中包含的大量动态行为信息。此外，没有努力将行为智能信息包括到深入强化学习（DRL）和机器人学习的知识图中。在本文中，我们提出了一种新颖的动态知识和技能图（KSG），然后我们基于CN-DBPEDIA开发了基本和特定的KSG。节点分为实体和属性节点，其中包含代理，环境和技能（DRL策略或策略表示）的实体节点，以及包含实体描述，预训练网络和离线数据集的属性节点。 KSG可以在各种环境中搜索不同代理的技能，并提供可转移的信息以获取新技能。这是我们意识到的第一项研究，研究了动态的KSG，以进行技能检索和学习。新技能学习的广泛实验结果表明，KSG提高了新的技能学习效率。

在大多数现实世界中的推荐方案中，多种行为（例如，单击，添加到购物车，采购等）的多类型，这对于学习用户的多方面偏好是有益的。由于多种类型的行为明确表现出依赖性，因此有效地对复杂行为依赖性建模对于多行为预测至关重要。最先进的多行为模型以所有历史互动为输入都没有区别地学习行为依赖性。但是，不同的行为可能反映了用户偏好的不同方面，这意味着某些无关的互动可能会像预测目标行为的声音一样发挥作用。为了解决上述局限性，我们向多行为建议介绍了多功能学习。更具体地说，我们提出了一种新颖的粗到五个知识增强的多功能学习（CKML）框架，以学习不同行为的共享和特定于行为的利益。 CKML引入了两个高级模块，即粗粒兴趣提取（CIE）和细粒度的行为相关性（FBC），它们共同起作用以捕获细粒度的行为依赖性。 CIE使用知识感知信息来提取每个兴趣的初始表示。 FBC结合了动态路由方案，以在兴趣之间进一步分配每个行为。此外，我们使用自我注意机制在兴趣水平上将不同的行为信息相关联。三个现实世界数据集的经验结果验证了我们模型在利用多行为数据方面的有效性和效率。进一步的实验证明了每个模块的有效性以及多行为数据共享和特定建模范式的鲁棒性和优越性。

在联合学习（FL）问题中，客户采样在训练算法的收敛速度中起着关键作用。然而，虽然是FL中的一个重要问题，但客户采样缺乏研究。在本文中，我们提出了在线学习，使用强盗反馈框架来了解FL中的客户采样问题。通过调整在线随机镜血清序列算法，以最小化梯度估计的方差，我们提出了一种新的自适应客户端采样算法。此外，我们使用在线集合方法和加倍技巧来自动选择算法中的调整参数。从理论上讲，我们将动态遗憾与比较器相结合，作为理论上最佳采样序列;我们还包括在我们的上限中的该序列的总变化，这是对问题的内在难度的自然度量。据我们所知，这些理论贡献对现有文献进行了新颖。此外，通过实施合成和真实数据实验，我们展示了我们所提出的算法在广泛使用的统一采样中的优势以及以前研究的其他在线学习的采样策略的实证证据。我们还检查其对调谐参数的选择的鲁棒性。最后，我们讨论其可能的延伸，而无需更换和个性化的流动。虽然原始目标是解决客户的采样问题，但这项工作在随机梯度下降和随机坐标序列方法上具有更大的应用。

在基于LIDAR的自主驱动的基于LIDAR的3D对象检测中，与2D检测情况相比，对象尺寸与输入场景尺寸的比率明显较小。俯瞰此差异，许多3D探测器直接遵循2D探测器的常见做法，即使在量化点云之后，也可以将特征映射下来。在本文中，我们首先重新思考这种多级刻板印象如何影响基于激光雷达的3D对象探测器。我们的实验指出，下采样操作带来了一些优势，并导致不可避免的信息损失。要解决此问题，我们提出了单程稀疏变压器（SST），以将原始分辨率从网络的开头维护。我们的方法武装变压器，我们的方法解决了单步体系结构中的接收领域不足的问题。它还与点云的稀疏合作，自然避免昂贵的计算。最终，我们的SST在大型Waymo Open DataSet上实现了最先进的结果。值得一提的是，由于单程的特征，我们的方法可以在小物体（行人）检测上实现令人兴奋的性能（83.8级）对小物体（行人）检测。代码将在https://github.com/tusimple/sst释放

近年来，对主动无线胶囊内窥镜（WCE）的同时磁力驱动和定位（SMAL）进行了集中研究，以提高检查的效率和准确性。在本文中，我们提出了一种用于主动WCE的自主磁导航框架，其模仿常规结肠镜检查的专家医师的“插入”和“提取”程序，从而使机器人胶囊内窥镜在肠道中有效和准确地进行了最小的用户努力。首先，胶囊通过未知的肠道环境自动推进，并产生一种代表环境的可行路径。然后，胶囊被自主地驶向肠道轨迹上选择的任何点，以便准确和反复检查可疑病变。此外，我们在加入高级Smal算法的机器人系统上实现了导航框架，并在使用幽灵和前体内猪结肠中验证各种管状环境的导航中。我们的结果表明，拟议的自主导航框架可以有效地在未知，复杂的管状环境中导航胶囊，其与手动操作相比具有令人满意的精度，重复性和效率。