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.

Recently, spoken dialogue systems have been widely deployed in a variety of applications, serving a huge number of end-users. A common issue is that the errors resulting from noisy utterances, semantic misunderstandings, or lack of knowledge make it hard for a real system to respond properly, possibly leading to an unsatisfactory user experience. To avoid such a case, we consider a proactive interaction mechanism where the system predicts the user satisfaction with the candidate response before giving it to the user. If the user is not likely to be satisfied according to the prediction, the system will ask the user a suitable question to determine the real intent of the user instead of providing the response directly. With such an interaction with the user, the system can give a better response to the user. Previous models that predict the user satisfaction are not applicable to DuerOS which is a large-scale commercial dialogue system. They are based on hand-crafted features and thus can hardly learn the complex patterns lying behind millions of conversations and temporal dependency in multiple turns of the conversation. Moreover, they are trained and evaluated on the benchmark datasets with adequate labels, which are expensive to obtain in a commercial dialogue system. To face these challenges, we propose a pipeline to predict the user satisfaction to help DuerOS decide whether to ask for clarification in each turn. Specifically, we propose to first generate a large number of weak labels and then train a transformer-based model to predict the user satisfaction with these weak labels. Empirically, we deploy and evaluate our model on DuerOS, and observe a 19% relative improvement on the accuracy of user satisfaction prediction and 2.3% relative improvement on user experience.

Cross-modality magnetic resonance (MR) image synthesis aims to produce missing modalities from existing ones. Currently, several methods based on deep neural networks have been developed using both source- and target-modalities in a supervised learning manner. However, it remains challenging to obtain a large amount of completely paired multi-modal training data, which inhibits the effectiveness of existing methods. In this paper, we propose a novel Self-supervised Learning-based Multi-scale Transformer Network (SLMT-Net) for cross-modality MR image synthesis, consisting of two stages, \ie, a pre-training stage and a fine-tuning stage. During the pre-training stage, we propose an Edge-preserving Masked AutoEncoder (Edge-MAE), which preserves the contextual and edge information by simultaneously conducting the image reconstruction and the edge generation. Besides, a patch-wise loss is proposed to treat the input patches differently regarding their reconstruction difficulty, by measuring the difference between the reconstructed image and the ground-truth. In this case, our Edge-MAE can fully leverage a large amount of unpaired multi-modal data to learn effective feature representations. During the fine-tuning stage, we present a Multi-scale Transformer U-Net (MT-UNet) to synthesize the target-modality images, in which a Dual-scale Selective Fusion (DSF) module is proposed to fully integrate multi-scale features extracted from the encoder of the pre-trained Edge-MAE. Moreover, we use the pre-trained encoder as a feature consistency module to measure the difference between high-level features of the synthesized image and the ground truth one. Experimental results show the effectiveness of the proposed SLMT-Net, and our model can reliably synthesize high-quality images when the training set is partially unpaired. Our code will be publicly available at https://github.com/lyhkevin/SLMT-Net.

The problem of covariate-shift generalization has attracted intensive research attention. Previous stable learning algorithms employ sample reweighting schemes to decorrelate the covariates when there is no explicit domain information about training data. However, with finite samples, it is difficult to achieve the desirable weights that ensure perfect independence to get rid of the unstable variables. Besides, decorrelating within stable variables may bring about high variance of learned models because of the over-reduced effective sample size. A tremendous sample size is required for these algorithms to work. In this paper, with theoretical justification, we propose SVI (Sparse Variable Independence) for the covariate-shift generalization problem. We introduce sparsity constraint to compensate for the imperfectness of sample reweighting under the finite-sample setting in previous methods. Furthermore, we organically combine independence-based sample reweighting and sparsity-based variable selection in an iterative way to avoid decorrelating within stable variables, increasing the effective sample size to alleviate variance inflation. Experiments on both synthetic and real-world datasets demonstrate the improvement of covariate-shift generalization performance brought by SVI.

We discuss a platform that has both software and hardware components, and whose purpose is to support research into characterizing and mitigating the sim-to-real gap in robotics and vehicle autonomy engineering. The software is operating-system independent and has three main components: a simulation engine called Chrono, which supports high-fidelity vehicle and sensor simulation; an autonomy stack for algorithm design and testing; and a development environment that supports visualization and hardware-in-the-loop experimentation. The accompanying hardware platform is a 1/6th scale vehicle augmented with reconfigurable mountings for computing, sensing, and tracking. Since this vehicle platform has a digital twin within the simulation environment, one can test the same autonomy perception, state estimation, or controls algorithms, as well as the processors they run on, in both simulation and reality. A demonstration is provided to show the utilization of this platform for autonomy research. Future work will concentrate on augmenting ART/ATK with support for a full-sized Chevy Bolt EUV, which will be made available to this group in the immediate future.

与大脑变化相关的阿尔茨海默氏病（AD）和轻度认知障碍（MCI）的评估仍然是一项艰巨的任务。最近的研究表明，多模式成像技术的组合可以更好地反映病理特征，并有助于更准确地诊断AD和MCI。在本文中，我们提出了一种新型的基于张量的多模式特征选择和回归方法，用于诊断和生物标志物对正常对照组的AD和MCI鉴定。具体而言，我们利用张量结构来利用多模式数据中固有的高级相关信息，并研究多线性回归模型中的张量级稀疏性。我们使用三种成像方式（VBM- MRI，FDG-PET和AV45-PET）具有疾病严重程度和认知评分的临床参数来分析ADNI数据的方法的实际优势。实验结果表明，我们提出的方法与疾病诊断的最新方法的优越性能以及疾病特异性区域和与模态相关的差异的鉴定。这项工作的代码可在https://github.com/junfish/bios22上公开获得。

胸部X射线（CXR）中准确的异常定位可以使各种胸部疾病的临床诊断受益。但是，病变水平的注释只能由经验丰富的放射科医生进行，这是乏味且耗时的，因此很难获得。这种情况导致难以开发CXR的完全监督异常定位系统。在这方面，我们建议通过一个弱半监督的策略来训练CXR异常本地化框架，称为“超越阶级”（PBC），该策略（PBC）使用了少数带有病变级别边界框的完全注释的CXR，并通过广泛的弱化的样品和大量的带有注释的样品。点。这样的点注释设置可以通过边缘注释成本提供弱实例级信息，以实现异常定位。尤其是，我们的PBC背后的核心思想是学习从点注释到边界框的强大而准确的映射，以根据注释点的差异。为此，提出了一个正则化项，即多点的一致性，它驱动模型从相同异常内的不同点注释中生成一致的边界框。此外，还提出了一种被称为对称的一致性的自学，也提出了从弱注释的数据中深入利用有用的信息来实现异常定位。 RSNA和VINDR-CXR数据集的实验结果证明了该方法的有效性。当使用少于20％的盒子级标签进行训练时，与当前的最新方法相比，我们的PBC可以在MAP中提高〜5的改进（即点DETR）。代码可从https://github.com/haozheliu-st/point-beyond-class获得。

多模式的医学图像完成已广泛应用，以减轻许多多模式诊断任务中缺失的模式问题。但是，对于大多数现有的合成方法，它们缺失模式的推断可能会崩溃为确定性映射，从而忽略了跨模式关系中固有的不确定性。在这里，我们提出了统一的多模式条件分数的生成模型（UMM-CSGM），以利用基于得分的生成模型（SGM）在建模和随机采样目标概率分布中，并进一步将SGM扩展到交叉模式统一框架中各种缺失模式配置的条件合成。具体而言，UMM-CSGM采用一种新型的多中心条件分数网络（MM-CSN），通过在完整的模态空间中的条件扩散和反向产生来学习一组综合的跨模式条件分布。通过这种方式，可以通过所有可用信息来准确地制定生成过程，并可以符合单个网络中缺少模式的所有可能配置。 BRATS19数据集的实验表明，UMM-CSGM可以更可靠地合成肿瘤诱导的任何缺失方式的肿瘤诱导病变中的异质增强和不规则面积。

语言模型既展示了定量的改进，又展示了新的定性功能，随着规模的增加。尽管它们具有潜在的变革性影响，但这些新能力的特征却很差。为了为未来的研究提供信息，为破坏性的新模型能力做准备，并改善社会有害的效果，至关重要的是，我们必须了解目前和近乎未来的能力和语言模型的局限性。为了应对这一挑战，我们介绍了超越模仿游戏基准（Big Bench）。 Big Bench目前由204个任务组成，由132家机构的442位作者贡献。任务主题是多样的，从语言学，儿童发展，数学，常识性推理，生物学，物理学，社会偏见，软件开发等等。 Big-Bench专注于被认为超出当前语言模型的功能的任务。我们评估了OpenAI的GPT型号，Google内部密集变压器体系结构和大型基础上的开关稀疏变压器的行为，跨越了数百万到数十亿个参数。此外，一个人类专家评估者团队执行了所有任务，以提供强大的基准。研究结果包括：模型性能和校准都随规模改善，但绝对的术语（以及与评估者的性能相比）；在模型类中的性能非常相似，尽管带有稀疏性。逐渐和预测的任务通常涉及大量知识或记忆成分，而在临界规模上表现出“突破性”行为的任务通常涉及多个步骤或组成部分或脆性指标；社交偏见通常会随着含糊不清的环境而随着规模而增加，但这可以通过提示来改善。

非负矩阵分解（NMF）已广泛用于降低机器学习的尺寸。但是，传统的NMF无法正确处理异常值，因此对噪声敏感。为了提高NMF的鲁棒性，本文提出了一种自适应加权NMF，它引入了权重，以强调每个数据点的不同重要性，因此降低了对噪声数据的算法敏感性。它与使用缓慢生长相似性度量的现有强大NMF大不相同。具体而言，提出了两种实现这一目标的策略：模糊加权技术和熵加权技术，两者都导致具有简单形式的迭代解决方案。实验结果表明，新方法在具有噪声的几个真实数据集上具有更健壮的特征表示，而不是进行噪声。