部分可观察到的马尔可夫决策过程（POMDP）是适用于许多现实世界问题的框架。在这项工作中，我们提出了一种方法，通过依靠解决完全可观察的版本的策略来解决具有多模式信念的POMDP。通过deleinig，基于完全可观察到的变体的值函数的新的混合价值函数，我们可以使用相应的贪婪策略来求解POMDP本身。我们开发了讨论所需的数学框架，并引入了基于侦察盲tictactoe的任务的基准。在此基准测试中，我们表明我们的政策优于政策，而忽略了多种模式的存在。

We study the ability of foundation models to learn representations for classification that are transferable to new, unseen classes. Recent results in the literature show that representations learned by a single classifier over many classes are competitive on few-shot learning problems with representations learned by special-purpose algorithms designed for such problems. We offer an explanation for this phenomenon based on the concept of class-features variability collapse, which refers to the training dynamics of deep classification networks where the feature embeddings of samples belonging to the same class tend to concentrate around their class means. More specifically, we examine the few-shot error of the learned feature map, which is the classification error of the nearest class-center classifier using centers learned from a small number of random samples from each class. Assuming that the classes appearing in the data are selected independently from a distribution, we show that the few-shot error generalizes from the training data to unseen test data, and we provide an upper bound on the expected few-shot error for new classes (selected from the same distribution) using the average few-shot error for the source classes. Additionally, we show that the few-shot error on the training data can be upper bounded using the degree of class-features variability collapse. This suggests that foundation models can provide feature maps that are transferable to new downstream tasks even with limited data available.

We study the learning dynamics of self-predictive learning for reinforcement learning, a family of algorithms that learn representations by minimizing the prediction error of their own future latent representations. Despite its recent empirical success, such algorithms have an apparent defect: trivial representations (such as constants) minimize the prediction error, yet it is obviously undesirable to converge to such solutions. Our central insight is that careful designs of the optimization dynamics are critical to learning meaningful representations. We identify that a faster paced optimization of the predictor and semi-gradient updates on the representation, are crucial to preventing the representation collapse. Then in an idealized setup, we show self-predictive learning dynamics carries out spectral decomposition on the state transition matrix, effectively capturing information of the transition dynamics. Building on the theoretical insights, we propose bidirectional self-predictive learning, a novel self-predictive algorithm that learns two representations simultaneously. We examine the robustness of our theoretical insights with a number of small-scale experiments and showcase the promise of the novel representation learning algorithm with large-scale experiments.

Dyadic and small group collaboration is an evolutionary advantageous behaviour and the need for such collaboration is a regular occurrence in day to day life. In this paper we estimate the perceived personality traits of individuals in dyadic and small groups over thin-slices of interaction on four multimodal datasets. We find that our transformer based predictive model performs similarly to human annotators tasked with predicting the perceived big-five personality traits of participants. Using this model we analyse the estimated perceived personality traits of individuals performing tasks in small groups and dyads. Permutation analysis shows that in the case of small groups undergoing collaborative tasks, the perceived personality of group members clusters, this is also observed for dyads in a collaborative problem solving task, but not in dyads under non-collaborative task settings. Additionally, we find that the group level average perceived personality traits provide a better predictor of group performance than the group level average self-reported personality traits.

To apply federated learning to drug discovery we developed a novel platform in the context of European Innovative Medicines Initiative (IMI) project MELLODDY (grant n{\deg}831472), which was comprised of 10 pharmaceutical companies, academic research labs, large industrial companies and startups. The MELLODDY platform was the first industry-scale platform to enable the creation of a global federated model for drug discovery without sharing the confidential data sets of the individual partners. The federated model was trained on the platform by aggregating the gradients of all contributing partners in a cryptographic, secure way following each training iteration. The platform was deployed on an Amazon Web Services (AWS) multi-account architecture running Kubernetes clusters in private subnets. Organisationally, the roles of the different partners were codified as different rights and permissions on the platform and administrated in a decentralized way. The MELLODDY platform generated new scientific discoveries which are described in a companion paper.

在法医语音比较中，扬声器的嵌入在过去十年中已广泛流行。大多数审计的扬声器嵌入式嵌入都经过英语语料库进行培训，因为它很容易访问。因此，语言依赖性可能是自动法医语音比较的重要因素，尤其是当目标语言在语言上非常不同时。有许多商业系统可用，但是它们的模型主要接受与目标语言不同的语言（主要是英语）的培训。在低资源语言的情况下，开发用于法医目的的语料库，其中包含足够的扬声器来训练深度学习模型是昂贵的。这项研究旨在调查是否可以在目标低资源语言（匈牙利语）上使用预先培训的英语语料库的模型，与模型不同。另外，通常没有犯罪者（未知的扬声器）获得多个样本。因此，在有或没有说话者入学率的嫌疑人（已知）扬声器的情况下对样品进行比较。应用了两个语料库，这些语料库是专门用于法医目的的，第三个是用于传统演讲者验证的第三个语料库。使用了两种基于深度学习的扬声器嵌入向量提取方法：X-Vector和Ecapa-TDNN。说话者验证在可能性比率框架中进行了评估。在语言组合（建模，LR校准，评估）之间进行了比较。通过MinCllr和EER指标评估了结果。发现该模型以不同的语言进行了预先训练，但是在具有大量扬声器的语料库上，在语言不匹配的样本上表现良好。还检查了样本持续时间和口语样式的影响。发现相关样本的持续时间越长，性能就越好。另外，如果采用各种口语样式，则没有真正的区别。

监督的机器学习为各种计算机视觉问题提供了最新的解决方案。但是，对大量标记的培训数据的需求限制了这些算法在稀缺或昂贵的情况下的这些算法的功能。自我监督的学习提供了一种方法，可以通过对未标记数据的特定域进行预处理模型来降低对手动注释数据的需求。在这种方法中，标记的数据完全需要用于微调下游任务的模型。医疗图像细分是一个标签数据需要专家知识并收集大型标记数据集的领域。因此，自我监督的学习算法有望在该领域进行实质性改进。尽管如此，自我监督的学习算法很少用于预识医学图像分割网络。在本文中，我们详细阐述并分析了对下游医学图像分割的监督和自我监督预审方法的有效性，重点是收敛和数据效率。我们发现，对自然图像和目标域特异性图像进行自我监督的预测会导致最快，最稳定的下游收敛性。在我们对ACDC心脏分割数据集的实验中，与Imagenet预处理的模型相比，这种预处理的方法可实现4-5倍的微调收敛。我们还表明，这种方法需要在域特异性数据上进行少于五个时期的预处理，以在下游收敛时间进行这种改进。最后，我们发现，在低数据方案中，有监督的Imagenet预处理达到了最佳准确性，需要少于100个带注释的样品才能实现接近最小误差。

使用深度学习神经网络的AI发动机为分析传统棋盘游戏提供了出色的工具。在这里，我们有兴趣获得对古老游戏的新见解。为此，我们需要根据发动机的原始输出来定义新的数值度量。在本文中，我们开发了一种数值工具，用于以上下文敏感的方式进行自动移动性能评估并识别游戏功能。我们通过传递成本来衡量移动的紧迫性，这是石头当前配置和在同一董事会位置的假设传递之后的得分值差。在这里，我们研究了此度量的属性并描述了一些应用。

长期以来，共同基金或交易所交易基金（ETF）的分类已为财务分析师提供服务，以进行同行分析，以从竞争对手分析开始到量化投资组合多元化。分类方法通常依赖于从n-1a表格中提取的结构化格式的基金组成数据。在这里，我们启动一项研究，直接从使用自然语言处理（NLP）的表格中描绘的非结构化数据中学习分类系统。将输入数据仅作为表格中报告的投资策略描述，而目标变量是Lipper全球类别，并且使用各种NLP模型，我们表明，分类系统确实可以通过高准确率。我们讨论了我们发现的含义和应用，以及现有的预培训架构的局限性在应用它们以学习基金分类时。

在核成像中，有限的分辨率会导致影响图像清晰度和定量准确性的部分体积效应（PVE）。已证明来自CT或MRI的高分辨率解剖信息的部分体积校正（PVC）已被证明是有效的。但是，这种解剖学引导的方法通常需要乏味的图像注册和分割步骤。由于缺乏具有高端CT和相关运动伪像的混合体SPECT/CT扫描仪，因此很难获得准确的分段器官模板，尤其是在心脏SPECT成像中。轻微的错误注册/错误分段将导致PVC后的图像质量严重降解。在这项工作中，我们开发了一种基于深度学习的方法，用于快速心脏SPECT PVC，而无需解剖信息和相关的器官分割。所提出的网络涉及密集连接的多维动态机制，即使网络经过充分训练，也可以根据输入图像对卷积内核进行调整。引入了心脏内血容量（IMBV）作为网络优化的附加临床损失函数。提出的网络表明，使用Technetium-99M标记的红细胞在GE发现NM/CT 570C专用心脏SPECT扫描仪上获得的28个犬类研究表现有希望的表现。这项工作表明，与没有这种机制的同一网络相比，具有密集连接的动态机制的提议网络产生了较高的结果。结果还表明，没有解剖信息的提出的网络可以与解剖学引导的PVC方法产生的图像产生具有统计上可比的IMBV测量的图像，这可能有助于临床翻译。