深度学习的最近历史一直是成就之一：从游戏中的人类胜利到图像分类，语音识别，翻译和其他任务的世界领先表现。但是，这一进展带来了对计算能力的渴望。本文分类了这种依赖性的程度，表明各种应用程序的进展非常依赖于计算能力的增加。推断向前的信仰表明，沿当前线的进步正在经济，技术和环境上迅速变得不可持续。因此，在这些应用程序中的持续进展将需要更大的计算方法，这要么必须从变化到深度学习或转移到其他机器学习方法。

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.

This paper describes the 5th edition of the Predicting Video Memorability Task as part of MediaEval2022. This year we have reorganised and simplified the task in order to lubricate a greater depth of inquiry. Similar to last year, two datasets are provided in order to facilitate generalisation, however, this year we have replaced the TRECVid2019 Video-to-Text dataset with the VideoMem dataset in order to remedy underlying data quality issues, and to prioritise short-term memorability prediction by elevating the Memento10k dataset as the primary dataset. Additionally, a fully fledged electroencephalography (EEG)-based prediction sub-task is introduced. In this paper, we outline the core facets of the task and its constituent sub-tasks; describing the datasets, evaluation metrics, and requirements for participant submissions.

The Predicting Media Memorability task in the MediaEval evaluation campaign has been running annually since 2018 and several different tasks and data sets have been used in this time. This has allowed us to compare the performance of many memorability prediction techniques on the same data and in a reproducible way and to refine and improve on those techniques. The resources created to compute media memorability are now being used by researchers well beyond the actual evaluation campaign. In this paper we present a summary of the task, including the collective lessons we have learned for the research community.

科学机器学习的进步改善了现代计算科学和工程应用。数据驱动的方法（例如动态模式分解（DMD））可以从动态系统生成的时空数据中提取相干结构，并推断上述系统的不同方案。时空数据作为快照，每次瞬间包含空间信息。在现代工程应用中，高维快照的产生可能是时间和/或资源要求。在本研究中，我们考虑了在大型数值模拟中增强DMD工作流程的两种策略：（i）快照压缩以减轻磁盘压力； （ii）使用原位可视化图像在运行时重建动力学（或部分）。我们通过两个3D流体动力学模拟评估我们的方法，并考虑DMD重建解决方案。结果表明，快照压缩大大减少了所需的磁盘空间。我们已经观察到，损耗的压缩将存储降低了几乎$ 50 \％$，而信号重建和其他关注数量的相对错误则较低。我们还使用原位可视化工具将分析扩展到了直接生成的数据，在运行时生成状态向量的图像文件。在大型模拟中，快照的产生可能足够慢，可以使用批处理算法进行推理。流DMD利用增量SVD算法，并随着每个新快照的到来更新模式。我们使用流式DMD来重建原位生成的图像的动力学。我们证明此过程是有效的，并且重建的动力学是准确的。

宇宙学调查实验中的数据处理和分析管道引入了数据扰动，可以显着降低基于深度学习的模型的性能。鉴于加工和分析宇宙学调查数据的监督深度学习方法的增加，数据扰动效应的评估以及增加模型稳健性的方法的发展越来越重要。在星系形态分类的背景下，我们研究了扰动在成像数据中的影响。特别是，我们在基线数据培训和扰动数据测试时检查使用神经网络的后果。我们考虑与两个主要来源相关的扰动：1）通过泊松噪声和2）诸如图像压缩或望远镜误差的图像压缩或望远粉误差所产生的步骤所产生的数据处理噪声提高了观测噪声。我们还测试了域适应技术在减轻扰动驱动误差时的功效。我们使用分类准确性，潜在空间可视化和潜在空间距离来评估模型稳健性。如果没有域适应，我们发现处理像素级别错误容易将分类翻转成一个不正确的类，并且更高的观察噪声使得模型在低噪声数据上培训无法对Galaxy形态进行分类。另一方面，我们表明，具有域适应的培训改善了模型稳健性并减轻了这些扰动的影响，以更高的观测噪声的数据提高了23％的分类精度。域适应也增加了基线与错误分类的错误分类的潜在空间距离〜2.3的倍数距离，使模型更强大地扰动。

本文介绍了预测媒体难忘性的Mediaeval 2021，这是今年第4版的任务，因为短期和长期视频难忘性的预测仍然是一个具有挑战性的任务。在2021年，使用两个视频数据集：第一，TRECVID 2019视频到文本数据集的子集;其次，Memento10K数据集是为了提供探索交叉数据集泛化的机会。另外，介绍了基于脑电图（EEG）的预测导频子任务。在本文中，我们概述了任务的主要方面，并描述了参与者提交的数据集，评估指标和要求。

使用公共可用链路的集合，平均每周6秒的视频剪辑，每次，1,275用户多次手动注释每个视频，以指示视频的长期和短期难忘性。注释作为在线记忆游戏的一部分，并测量了参与者在显示视频的集合时先前召回过视频的能力。在前几分钟内看到的视频进行识别任务，以进行短期令人难忘，以便在前24到72小时内进行长期难忘。数据包括每个视频的每个识别的反应时间。与每个视频相关联是文本描述（标题）以及应用于从每个视频中提取的3帧的图像级别功能集合（开始，中间和结束）。还提供了视频级功能。数据集在视频难忘任务中使用，作为2020年的Mediaeval基准的一部分。

This paper presents a machine learning approach to multidimensional item response theory (MIRT), a class of latent factor models that can be used to model and predict student performance from observed assessment data. Inspired by collaborative filtering, we define a general class of models that includes many MIRT models. We discuss the use of penalized joint maximum likelihood (JML) to estimate individual models and cross-validation to select the best performing model. This model evaluation process can be optimized using batching techniques, such that even sparse large-scale data can be analyzed efficiently. We illustrate our approach with simulated and real data, including an example from a massive open online course (MOOC). The high-dimensional model fit to this large and sparse dataset does not lend itself well to traditional methods of factor interpretation. By analogy to recommender-system applications, we propose an alternative "validation" of the factor model, using auxiliary information about the popularity of items consulted during an open-book exam in the course.

Non-linear state-space models, also known as general hidden Markov models, are ubiquitous in statistical machine learning, being the most classical generative models for serial data and sequences in general. The particle-based, rapid incremental smoother PaRIS is a sequential Monte Carlo (SMC) technique allowing for efficient online approximation of expectations of additive functionals under the smoothing distribution in these models. Such expectations appear naturally in several learning contexts, such as likelihood estimation (MLE) and Markov score climbing (MSC). PARIS has linear computational complexity, limited memory requirements and comes with non-asymptotic bounds, convergence results and stability guarantees. Still, being based on self-normalised importance sampling, the PaRIS estimator is biased. Our first contribution is to design a novel additive smoothing algorithm, the Parisian particle Gibbs PPG sampler, which can be viewed as a PaRIS algorithm driven by conditional SMC moves, resulting in bias-reduced estimates of the targeted quantities. We substantiate the PPG algorithm with theoretical results, including new bounds on bias and variance as well as deviation inequalities. Our second contribution is to apply PPG in a learning framework, covering MLE and MSC as special examples. In this context, we establish, under standard assumptions, non-asymptotic bounds highlighting the value of bias reduction and the implicit Rao--Blackwellization of PPG. These are the first non-asymptotic results of this kind in this setting. We illustrate our theoretical results with numerical experiments supporting our claims.