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.

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.

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.

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.

许多古典童话，小说和剧本都利用对话来推进故事情节并建立角色。我们提出了第一个研究，以探索机器是否可以理解和产生故事中的对话，这需要捕获不同角色的特征及其之间的关系。为此，我们提出了两项​​新任务，包括蒙版对话生成和对话演讲者的认可，即分别产生对话转弯和预测说话者的指定对话转弯。我们构建了一个新的数据集拨号故事，该数据集由105K中国故事组成，其中包含大量对话，以支持评估。我们通过对拨号故事进行自动和手动评估测试现有模型来显示提出的任务的困难。此外，我们建议学习明确的角色表示，以提高这些任务的绩效。广泛的实验和案例研究表明，我们的方法可以产生更连贯和信息丰富的对话，并获得比强基础更高的说话者识别精度。

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。

游戏由多种类型的内容组成，而不同内容类型的和谐在游戏设计中起着至关重要的作用。但是，大多数关于程序内容生成的作品一次仅考虑一种类型的内容。在本文中，我们通过音乐提出并制定了从音乐中的在线水平生成，以实时的方式将级别功能与音乐功能匹配，同时适应玩家的比赛速度。一个通用框架通过强化学习为在线玩家自适应的程序内容生成，oparl for Short是建立在经验驱动的强化学习和可控制的强化学习的基础上的，以从音乐中获得在线水平的生成。此外，提出了基于本地搜索和K-Nearest邻居的新型控制策略，并将其集成到Oparl中，以控制在线收集的播放数据的水平发电机。基于仿真的实验的结果表明，我们实施Oparl有能力在在线方式以``Energy''动态的``能量''动态来生成可玩水平。

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。

强化学习算法在竞争挑战板和视频游戏时表现良好。越来越多的研究工作侧重于提高加强学习算法的泛化能力。普通视频游戏AI学习竞赛旨在设计能够学习在培训期间出现不同游戏水平的代理商。本文总结了五年的一般视频游戏AI学习竞争。在每个版本，设计了三场新游戏。对于每场比赛，通过扰动或组合两个训练水平来产生三个测试水平。然后，我们提出了一种新颖的加强学习框架，对一般视频游戏的双程观察，在假设中，它更有可能在不同级别而不是全局信息中观察到类似的本地信息。因此，我们所提出的框架而不是直接输入基于目前游戏屏幕的单个原始像素的屏幕截图，而是将游戏屏幕的编码，转换的全局和本地观测视为两个同时输入，旨在学习播放新级别的本地信息。我们提出的框架是用三种最先进的加强学习算法实施，并在2020年普通视频游戏AI学习竞赛的游戏集上进行了测试。消融研究表明，使用编码，转换的全局和本地观察的出色性能。总体上最好的代理商进一步用作2021次竞赛版的基线。