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.
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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.
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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。
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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。
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图形神经网络(GNN)在各种图挖掘任务中取得了巨大的成功。但是,当GNN堆叠着许多层时,总是观察到急剧性能降解。结果,大多数GNN仅具有浅层建筑,这限制了它们的表现力和对深社区的开发。最近的研究将深度GNN的性能降低归因于\ textit {过度平滑}的问题。在本文中,我们将传统的图形卷积操作分为两个独立操作:\ textit {passagation}(\ textbf {p})和\ textit {transformation}(\ textbf {t})。可以分为传播深度($ d_p $)和转换深度($ d_t $)。通过广泛的实验,我们发现深度GNNS性能下降的主要原因是\ textit {model dygradation}问题是由大$ d_t $而不是\ textit {过度平滑}问题引起的,主要是由大$ d_p $引起的。 。此外,我们提出\ textIt {自适应初始残留}(air),一个与各种GNN架构兼容的插件模块,以减轻\ textit {model {model dradation degradation}问题和\ textit {textit {过度敏感}问题同时。六个现实世界数据集的实验结果表明,配备空气的GNN胜过大多数具有浅层建筑的GNN,这是由于大型$ d_p $和$ d_t $的好处,而与空气相关的时间成本则可以忽略。
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In this paper, we study the problem of knowledge-intensive text-to-SQL, in which domain knowledge is necessary to parse expert questions into SQL queries over domain-specific tables. We formalize this scenario by building a new Chinese benchmark KnowSQL consisting of domain-specific questions covering various domains. We then address this problem by presenting formulaic knowledge, rather than by annotating additional data examples. More concretely, we construct a formulaic knowledge bank as a domain knowledge base and propose a framework (ReGrouP) to leverage this formulaic knowledge during parsing. Experiments using ReGrouP demonstrate a significant 28.2% improvement overall on KnowSQL.
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Weakly-supervised object localization aims to indicate the category as well as the scope of an object in an image given only the image-level labels. Most of the existing works are based on Class Activation Mapping (CAM) and endeavor to enlarge the discriminative area inside the activation map to perceive the whole object, yet ignore the co-occurrence confounder of the object and context (e.g., fish and water), which makes the model inspection hard to distinguish object boundaries. Besides, the use of CAM also brings a dilemma problem that the classification and localization always suffer from a performance gap and can not reach their highest accuracy simultaneously. In this paper, we propose a casual knowledge distillation method, dubbed KD-CI-CAM, to address these two under-explored issues in one go. More specifically, we tackle the co-occurrence context confounder problem via causal intervention (CI), which explores the causalities among image features, contexts, and categories to eliminate the biased object-context entanglement in the class activation maps. Based on the de-biased object feature, we additionally propose a multi-teacher causal distillation framework to balance the absorption of classification knowledge and localization knowledge during model training. Extensive experiments on several benchmarks demonstrate the effectiveness of KD-CI-CAM in learning clear object boundaries from confounding contexts and addressing the dilemma problem between classification and localization performance.
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Dynamic treatment regimes assign personalized treatments to patients sequentially over time based on their baseline information and time-varying covariates. In mobile health applications, these covariates are typically collected at different frequencies over a long time horizon. In this paper, we propose a deep spectral Q-learning algorithm, which integrates principal component analysis (PCA) with deep Q-learning to handle the mixed frequency data. In theory, we prove that the mean return under the estimated optimal policy converges to that under the optimal one and establish its rate of convergence. The usefulness of our proposal is further illustrated via simulations and an application to a diabetes dataset.
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Nowadays, time-stamped web documents related to a general news query floods spread throughout the Internet, and timeline summarization targets concisely summarizing the evolution trajectory of events along the timeline. Unlike traditional document summarization, timeline summarization needs to model the time series information of the input events and summarize important events in chronological order. To tackle this challenge, in this paper, we propose a Unified Timeline Summarizer (UTS) that can generate abstractive and extractive timeline summaries in time order. Concretely, in the encoder part, we propose a graph-based event encoder that relates multiple events according to their content dependency and learns a global representation of each event. In the decoder part, to ensure the chronological order of the abstractive summary, we propose to extract the feature of event-level attention in its generation process with sequential information remained and use it to simulate the evolutionary attention of the ground truth summary. The event-level attention can also be used to assist in extracting summary, where the extracted summary also comes in time sequence. We augment the previous Chinese large-scale timeline summarization dataset and collect a new English timeline dataset. Extensive experiments conducted on these datasets and on the out-of-domain Timeline 17 dataset show that UTS achieves state-of-the-art performance in terms of both automatic and human evaluations.
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Hybrid unmanned aerial vehicles (UAVs) integrate the efficient forward flight of fixed-wing and vertical takeoff and landing (VTOL) capabilities of multicopter UAVs. This paper presents the modeling, control and simulation of a new type of hybrid micro-small UAVs, coined as lifting-wing quadcopters. The airframe orientation of the lifting wing needs to tilt a specific angle often within $ 45$ degrees, neither nearly $ 90$ nor approximately $ 0$ degrees. Compared with some convertiplane and tail-sitter UAVs, the lifting-wing quadcopter has a highly reliable structure, robust wind resistance, low cruise speed and reliable transition flight, making it potential to work fully-autonomous outdoor or some confined airspace indoor. In the modeling part, forces and moments generated by both lifting wing and rotors are considered. Based on the established model, a unified controller for the full flight phase is designed. The controller has the capability of uniformly treating the hovering and forward flight, and enables a continuous transition between two modes, depending on the velocity command. What is more, by taking rotor thrust and aerodynamic force under consideration simultaneously, a control allocation based on optimization is utilized to realize cooperative control for energy saving. Finally, comprehensive Hardware-In-the-Loop (HIL) simulations are performed to verify the advantages of the designed aircraft and the proposed controller.
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