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.

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.

The instrumental variable (IV) approach is a widely used way to estimate the causal effects of a treatment on an outcome of interest from observational data with latent confounders. A standard IV is expected to be related to the treatment variable and independent of all other variables in the system. However, it is challenging to search for a standard IV from data directly due to the strict conditions. The conditional IV (CIV) method has been proposed to allow a variable to be an instrument conditioning on a set of variables, allowing a wider choice of possible IVs and enabling broader practical applications of the IV approach. Nevertheless, there is not a data-driven method to discover a CIV and its conditioning set directly from data. To fill this gap, in this paper, we propose to learn the representations of the information of a CIV and its conditioning set from data with latent confounders for average causal effect estimation. By taking advantage of deep generative models, we develop a novel data-driven approach for simultaneously learning the representation of a CIV from measured variables and generating the representation of its conditioning set given measured variables. Extensive experiments on synthetic and real-world datasets show that our method outperforms the existing IV methods.

可以测量接触物体的3D几何形状的基于视觉的触觉传感器对于机器人执行灵巧的操纵任务至关重要。但是，现有的传感器通常很复杂，可以制造和细腻以扩展。在这项工作中，我们从小地利用了半透明弹性体的反射特性来设计一种名为DTACT的强大，低成本且易于制作的触觉传感器。DTACT从捕获的触觉图像中所示的黑暗中精确测量了高分辨率3D几何形状，仅具有单个图像进行校准。与以前的传感器相反，在各种照明条件下，DTACT是可靠的。然后，我们构建了具有非平面接触表面的DTACT原型，并以最少的额外努力和成本。最后，我们执行了两项智能机器人任务，包括使用DTACT进行姿势估计和对象识别，其中DTACT在应用中显示出巨大的潜力。

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。

许多研究都致力于学习公平代表的问题。但是，它们并未明确表示潜在表示之间的关系。在许多实际应用中，潜在表示之间可能存在因果关系。此外，大多数公平的表示学习方法都集中在群体级别的公平性上，并基于相关性，忽略了数据基础的因果关系。在这项工作中，我们从理论上证明，使用结构化表示可以使下游预测模型实现反事实公平，然后我们提出了反事实公平性变异自动编码器（CF-VAE）以获得有关领域知识的结构化表示。实验结果表明，所提出的方法比基准公平方法获得了更好的公平性和准确性性能。

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。

目前使用的无线胶囊内窥镜检查（WCE）是在检查时间和柔韧性方面有限的，因为胶囊被蠕动被动地移动，并且不能精确定位。已经提出了基于同时磁力驱动和定位技术的WCE的有效运动来促进不同的方法。在这项工作中，我们研究了在管状环境中旋转磁性致动下的机器人胶囊问题的轨迹，以实现使用无线胶囊内窥镜在给定点对肠道的安全，高效准确地检查肠道。具体而言，基于PD控制器，自适应控制器，模型预测控制器和鲁棒的多级模型预测控制器，开发了四种轨迹之后的策略。此外，我们的方法通过在控制器设计期间模拟肠蠕动和摩擦来考虑肠环境中的不确定性。我们验证了我们在仿真中的方法以及在各种管状环境中的实际实验中，包括具有不同形状和前体内猪结肠的塑料幽灵。结果表明，我们的方法可以有效地致动往复旋转的胶囊，以遵循复杂的管状环境中的所需轨迹，从而具有能够对高质量诊断进行准确和可重复检查的肠道。

Recent one-stage object detectors follow a per-pixel prediction approach that predicts both the object category scores and boundary positions from every single grid location. However, the most suitable positions for inferring different targets, i.e., the object category and boundaries, are generally different. Predicting all these targets from the same grid location thus may lead to sub-optimal results. In this paper, we analyze the suitable inference positions for object category and boundaries, and propose a prediction-target-decoupled detector named PDNet to establish a more flexible detection paradigm. Our PDNet with the prediction decoupling mechanism encodes different targets separately in different locations. A learnable prediction collection module is devised with two sets of dynamic points, i.e., dynamic boundary points and semantic points, to collect and aggregate the predictions from the favorable regions for localization and classification. We adopt a two-step strategy to learn these dynamic point positions, where the prior positions are estimated for different targets first, and the network further predicts residual offsets to the positions with better perceptions of the object properties. Extensive experiments on the MS COCO benchmark demonstrate the effectiveness and efficiency of our method. With a single ResNeXt-64x4d-101-DCN as the backbone, our detector achieves 50.1 AP with single-scale testing, which outperforms the state-of-the-art methods by an appreciable margin under the same experimental settings.Moreover, our detector is highly efficient as a one-stage framework. Our code is public at https://github.com/yangli18/PDNet.

In this paper we revisit endless online level generation with the recently proposed experience-driven procedural content generation via reinforcement learning (EDRL) framework, from an observation that EDRL tends to generate recurrent patterns. Inspired by this phenomenon, we formulate a notion of state space closure, which means that any state that may appear in an infinite-horizon online generation process can be found in a finite horizon. Through theoretical analysis we find that though state space closure arises a concern about diversity, it makes the EDRL trained on a finite-horizon generalised to the infinite-horizon scenario without deterioration of content quality. Moreover, we verify the quality and diversity of contents generated by EDRL via empirical studies on the widely used Super Mario Bros. benchmark. Experimental results reveal that the current EDRL approach's ability of generating diverse game levels is limited due to the state space closure, whereas it does not suffer from reward deterioration given a horizon longer than the one of training. Concluding our findings and analysis, we argue that future works in generating online diverse and high-quality contents via EDRL should address the issue of diversity on the premise of state space closure which ensures the quality.