Multivariate time series forecasting with hierarchical structure is pervasive in real-world applications, demanding not only predicting each level of the hierarchy, but also reconciling all forecasts to ensure coherency, i.e., the forecasts should satisfy the hierarchical aggregation constraints. Moreover, the disparities of statistical characteristics between levels can be huge, worsened by non-Gaussian distributions and non-linear correlations. To this extent, we propose a novel end-to-end hierarchical time series forecasting model, based on conditioned normalizing flow-based autoregressive transformer reconciliation, to represent complex data distribution while simultaneously reconciling the forecasts to ensure coherency. Unlike other state-of-the-art methods, we achieve the forecasting and reconciliation simultaneously without requiring any explicit post-processing step. In addition, by harnessing the power of deep model, we do not rely on any assumption such as unbiased estimates or Gaussian distribution. Our evaluation experiments are conducted on four real-world hierarchical datasets from different industrial domains (three public ones and a dataset from the application servers of Alipay's data center) and the preliminary results demonstrate efficacy of our proposed method.

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.

Semantic segmentation of Very High Resolution (VHR) remote sensing images is a fundamental task for many applications. However, large variations in the scales of objects in those VHR images pose a challenge for performing accurate semantic segmentation. Existing semantic segmentation networks are able to analyse an input image at up to four resizing scales, but this may be insufficient given the diversity of object scales. Therefore, Multi Scale (MS) test-time data augmentation is often used in practice to obtain more accurate segmentation results, which makes equal use of the segmentation results obtained at the different resizing scales. However, it was found in this study that different classes of objects had their preferred resizing scale for more accurate semantic segmentation. Based on this behaviour, a Stacking-Based Semantic Segmentation (SBSS) framework is proposed to improve the segmentation results by learning this behaviour, which contains a learnable Error Correction Module (ECM) for segmentation result fusion and an Error Correction Scheme (ECS) for computational complexity control. Two ECS, i.e., ECS-MS and ECS-SS, are proposed and investigated in this study. The Floating-point operations (Flops) required for ECS-MS and ECS-SS are similar to the commonly used MS test and the Single-Scale (SS) test, respectively. Extensive experiments on four datasets (i.e., Cityscapes, UAVid, LoveDA and Potsdam) show that SBSS is an effective and flexible framework. It achieved higher accuracy than MS when using ECS-MS, and similar accuracy as SS with a quarter of the memory footprint when using ECS-SS.

Image super-resolution is a common task on mobile and IoT devices, where one often needs to upscale and enhance low-resolution images and video frames. While numerous solutions have been proposed for this problem in the past, they are usually not compatible with low-power mobile NPUs having many computational and memory constraints. In this Mobile AI challenge, we address this problem and propose the participants to design an efficient quantized image super-resolution solution that can demonstrate a real-time performance on mobile NPUs. The participants were provided with the DIV2K dataset and trained INT8 models to do a high-quality 3X image upscaling. The runtime of all models was evaluated on the Synaptics VS680 Smart Home board with a dedicated edge NPU capable of accelerating quantized neural networks. All proposed solutions are fully compatible with the above NPU, demonstrating an up to 60 FPS rate when reconstructing Full HD resolution images. A detailed description of all models developed in the challenge is provided in this paper.

The role of mobile cameras increased dramatically over the past few years, leading to more and more research in automatic image quality enhancement and RAW photo processing. In this Mobile AI challenge, the target was to develop an efficient end-to-end AI-based image signal processing (ISP) pipeline replacing the standard mobile ISPs that can run on modern smartphone GPUs using TensorFlow Lite. The participants were provided with a large-scale Fujifilm UltraISP dataset consisting of thousands of paired photos captured with a normal mobile camera sensor and a professional 102MP medium-format FujiFilm GFX100 camera. The runtime of the resulting models was evaluated on the Snapdragon's 8 Gen 1 GPU that provides excellent acceleration results for the majority of common deep learning ops. The proposed solutions are compatible with all recent mobile GPUs, being able to process Full HD photos in less than 20-50 milliseconds while achieving high fidelity results. A detailed description of all models developed in this challenge is provided in this paper.

作为最成功的AI驱动应用程序之一，推荐系统的目的是通过在我们生活的许多方面提供个性化建议，以有效而有效的方式帮助人们做出适当的决定，尤其是针对各种面向人类的在线服务，例如E-商务平台和社交媒体网站。在过去的几十年中，推荐系统的快速发展通过创造经济价值，节省时间和精力以及促进社会利益，从而使人类受益匪浅。但是，最近的研究发现，数据驱动的推荐系统可能会对用户和社会构成严重威胁，例如传播虚假新闻以操纵社交媒体网站中的公众舆论，扩大不公平为代表性不足的团体或在工作匹配服务中的个人，或从建议结果中推断隐私信息。因此，系统的可信赖性一直吸引着各个方面的关注，以减轻推荐系统引起的负面影响，以增强公众对推荐系统技术的信任。在这项调查中，我们提供了可信赖的推荐系统（TREC）的全面概述，特别关注六个最重要的方面；即安全与鲁棒性，非歧视与公平，解释性，隐私，环境福祉以及问责制和可审计性。对于每个方面，我们总结了最近的相关技术，并讨论了潜在的研究方向，以帮助未来实现值得信赖的推荐系统。

基于深度学习的单图像超分辨率（SISR）方法引起了人们的关注，并在现代高级GPU上取得了巨大的成功。但是，大多数最先进的方法都需要大量参数，记忆和计算资源，这些参数通常会显示在当前移动设备CPU/NPU上时显示出较低的推理时间。在本文中，我们提出了一个简单的普通卷积网络，该网络具有快速最近的卷积模块（NCNET），该模块对NPU友好，可以实时执行可靠的超级分辨率。提出的最近的卷积具有与最近的UP采样相同的性能，但更快，更适合Android NNAPI。我们的模型可以很容易地在具有8位量化的移动设备上部署，并且与所有主要的移动AI加速器完全兼容。此外，我们对移动设备上的不同张量操作进行了全面的实验，以说明网络体系结构的效率。我们的NCNET在DIV2K 3X数据集上进行了训练和验证，并且与其他有效的SR方法的比较表明，NCNET可以实现高保真SR结果，同时使用更少的推理时间。我们的代码和预估计的模型可在\ url {https://github.com/algolzw/ncnet}上公开获得。

整个幻灯片图像（WSI）分类通常依赖于深度监督的多个实例学习（MIL）方法来处理Gigapixel分辨率图像和幻灯片级标签。然而，深度学习的不错的表现来自利用大量数据集和不同的样本，敦促需要有效的培训管道来扩展到大型数据集和数据增强技术以进行多元化样品。但是，当前基于MIL的WSI分类管道是内存量的且计算的，因为它们通常组装成千上万的补丁作为计算袋。另一方面，尽管它们在其他任务中很受欢迎，但对于WSI MIL Frameworks来说，数据增强尚未探索。为了解决它们，我们提出了Remix，这是基于MIL WSI分类的一般有效框架。它包括两个步骤：减少和混合。首先，它通过用实例原型（即贴片群质心）代替实例，从而减少了WSI袋中的实例数量。然后，我们提出了一个``混合式''增强，其中包含四个在线，随机和灵活的潜在空间扩展。它带来了潜在空间的多样化和可靠的班级身份的语义变化，同时实施语义扰动不变性。我们通过两种最先进的MIL方法在两个公共数据集上评估混音。在我们的实验中，已经实现了精确度，准确性和召回率的一致提高，但随着训练时间和记忆消耗的减少阶段，它表明了混音的有效性和效率。代码可用。

蛋白质是人类生命的重要组成部分，其结构对于功能和机制分析很重要。最近的工作表明了AI驱动方法对蛋白质结构预测的潜力。但是，新模型的开发受到数据集和基准测试培训程序的限制。据我们所知，现有的开源数据集远不足以满足现代蛋白质序列相关研究的需求。为了解决这个问题，我们介绍了具有高覆盖率和多样性的第一个百万级蛋白质结构预测数据集，称为PSP。该数据集由570K真实结构序列（10TB）和745K互补蒸馏序列（15TB）组成。此外，我们还提供了该数据集上SOTA蛋白结构预测模型的基准测试训练程序。我们通过参与客串比赛验证该数据集的实用程序进行培训，我们的模特赢得了第一名。我们希望我们的PSP数据集以及培训基准能够为AI驱动的蛋白质相关研究提供更广泛的AI/生物学研究人员社区。

在本文中，我们在多方会议场景中对说话者的自动语音识别（SA-ASR）进行了比较研究，这一主题越来越关注丰富的转录。具体而言，本研究评估了三种方法。第一种方法，即FD-SOT，由框架级诊断模型组成，以识别说话者和多对话者ASR以识别话语。通过对齐诊断结果和公认的假设，可以获得说话者归因的转录。但是，由于模块化的独立性，这种对齐策略可能会遭受错误的时间戳，从而严重阻碍了模型性能。因此，我们提出了第二种方法WD-SOT，以通过引入单词水平诊断模型来解决对齐误差，从而可以摆脱这种时间戳对齐依赖性。为了进一步缓解对齐问题，我们提出了第三种方法TS-ASR，该方法可以训练目标扬声器分离模块和ASR模块。通过比较每种SA-ASR方法的各种策略，对真实会议场景语料库的实验结果，AlimeTing，表明WD-SOT方法可在平均扬声器依赖性角色错误率（SD-CER）相对降低10.7％，与之相比FD-SOT方法。此外，TS-ASR方法还优于FD-SOT方法，并带来16.5％的相对平均SD-CER减少。