Diversity Searcher is a tool originally developed to help analyse diversity in news media texts. It relies on a form of automated content analysis and thus rests on prior assumptions and depends on certain design choices related to diversity and fairness. One such design choice is the external knowledge source(s) used. In this article, we discuss implications that these sources can have on the results of content analysis. We compare two data sources that Diversity Searcher has worked with - DBpedia and Wikidata - with respect to their ontological coverage and diversity, and describe implications for the resulting analyses of text corpora. We describe a case study of the relative over- or under-representation of Belgian political parties between 1990 and 2020 in the English-language DBpedia, the Dutch-language DBpedia, and Wikidata, and highlight the many decisions needed with regard to the design of this data analysis and the assumptions behind it, as well as implications from the results. In particular, we came across a staggering over-representation of the political right in the English-language DBpedia.

大型的预训练的语言模型成功地用于多种语言的各种任务中。随着这种不断增加的使用，有害副作用的风险也会上升，例如通过再现和加强刻板印象。但是，在解决多种语言或考虑不同的偏见时，发现和缓解这些危害通常很难做到，并且在计算上变得昂贵。为了解决这个问题，我们提出了Fairdistiltation：一种基于知识蒸馏的跨语性方法，可以在控制特定偏见的同时构建较小的语言模型。我们发现，我们的蒸馏方法不会对大多数任务的下游性能产生负面影响，并成功减轻刻板印象和代表性危害。我们证明，与替代方法相比，Fairdistillation可以以低得多的成本创建更公平的语言模型。

对自然语言处理资源中的偏置模式的提高意识，如BERT，具有许多度量来量化“偏见”和“公平”。但是，如果没有完全不可能，请比较不同指标的结果和评估这些度量的作品仍然困难。我们调查了对预用语言模型的公平度量标准的现有文献，并通过实验评估兼容性，包括语言模型中的偏差，如在其下游任务中。我们通过传统文献调查和相关分析的混合来实现这一目标，以及运行实证评估。我们发现许多指标不兼容，高度依赖于（i）模板，（ii）属性和目标种子和（iii）选择嵌入式。这些结果表明，公平或偏见评估对情境化语言模型仍然具有挑战性，如果不是至少高度主观。为了提高未来的比较和公平评估，我们建议避免嵌入基于的指标并专注于下游任务中的公平评估。

当技术进入有争议的社会辩论的悠久传统应用程序和流程，多方位的新的伦理和法律问题出现。本文拟就告密，活动与民主和业务产生巨大影响的主要论点集中的过程。计算机科学可以在历史上首次提供真正的匿名通信。我们相对于价值观和问责性，公平性和数据保护的权利调查此，着眼于机会，并可以计算提供了匿名的限制;外包告密支持可能导致的后果;和挑战的解释和使用的一些相关法律。我们的结论是，解决这些问题，告密和匿名举报必须依靠三大支柱，形成了在一个正式的技术意义收割机匿名“告密保护和incentivisation三角”;通过法律保护举报人;并组织和政治错误的文化。

Bias elimination and recent probing studies attempt to remove specific information from embedding spaces. Here it is important to remove as much of the target information as possible, while preserving any other information present. INLP is a popular recent method which removes specific information through iterative nullspace projections. Multiple iterations, however, increase the risk that information other than the target is negatively affected. We introduce two methods that find a single targeted projection: Mean Projection (MP, more efficient) and Tukey Median Projection (TMP, with theoretical guarantees). Our comparison between MP and INLP shows that (1) one MP projection removes linear separability based on the target and (2) MP has less impact on the overall space. Further analysis shows that applying random projections after MP leads to the same overall effects on the embedding space as the multiple projections of INLP. Applying one targeted (MP) projection hence is methodologically cleaner than applying multiple (INLP) projections that introduce random effects.

Besides the recent impressive results on reinforcement learning (RL), safety is still one of the major research challenges in RL. RL is a machine-learning approach to determine near-optimal policies in Markov decision processes (MDPs). In this paper, we consider the setting where the safety-relevant fragment of the MDP together with a temporal logic safety specification is given and many safety violations can be avoided by planning ahead a short time into the future. We propose an approach for online safety shielding of RL agents. During runtime, the shield analyses the safety of each available action. For any action, the shield computes the maximal probability to not violate the safety specification within the next $k$ steps when executing this action. Based on this probability and a given threshold, the shield decides whether to block an action from the agent. Existing offline shielding approaches compute exhaustively the safety of all state-action combinations ahead of time, resulting in huge computation times and large memory consumption. The intuition behind online shielding is to compute at runtime the set of all states that could be reached in the near future. For each of these states, the safety of all available actions is analysed and used for shielding as soon as one of the considered states is reached. Our approach is well suited for high-level planning problems where the time between decisions can be used for safety computations and it is sustainable for the agent to wait until these computations are finished. For our evaluation, we selected a 2-player version of the classical computer game SNAKE. The game represents a high-level planning problem that requires fast decisions and the multiplayer setting induces a large state space, which is computationally expensive to analyse exhaustively.

Safety is still one of the major research challenges in reinforcement learning (RL). In this paper, we address the problem of how to avoid safety violations of RL agents during exploration in probabilistic and partially unknown environments. Our approach combines automata learning for Markov Decision Processes (MDPs) and shield synthesis in an iterative approach. Initially, the MDP representing the environment is unknown. The agent starts exploring the environment and collects traces. From the collected traces, we passively learn MDPs that abstractly represent the safety-relevant aspects of the environment. Given a learned MDP and a safety specification, we construct a shield. For each state-action pair within a learned MDP, the shield computes exact probabilities on how likely it is that executing the action results in violating the specification from the current state within the next $k$ steps. After the shield is constructed, the shield is used during runtime and blocks any actions that induce a too large risk from the agent. The shielded agent continues to explore the environment and collects new data on the environment. Iteratively, we use the collected data to learn new MDPs with higher accuracy, resulting in turn in shields able to prevent more safety violations. We implemented our approach and present a detailed case study of a Q-learning agent exploring slippery Gridworlds. In our experiments, we show that as the agent explores more and more of the environment during training, the improved learned models lead to shields that are able to prevent many safety violations.

We review clustering as an analysis tool and the underlying concepts from an introductory perspective. What is clustering and how can clusterings be realised programmatically? How can data be represented and prepared for a clustering task? And how can clustering results be validated? Connectivity-based versus prototype-based approaches are reflected in the context of several popular methods: single-linkage, spectral embedding, k-means, and Gaussian mixtures are discussed as well as the density-based protocols (H)DBSCAN, Jarvis-Patrick, CommonNN, and density-peaks.

Recent advances in computer vision have shown promising results in image generation. Diffusion probabilistic models in particular have generated realistic images from textual input, as demonstrated by DALL-E 2, Imagen and Stable Diffusion. However, their use in medicine, where image data typically comprises three-dimensional volumes, has not been systematically evaluated. Synthetic images may play a crucial role in privacy preserving artificial intelligence and can also be used to augment small datasets. Here we show that diffusion probabilistic models can synthesize high quality medical imaging data, which we show for Magnetic Resonance Images (MRI) and Computed Tomography (CT) images. We provide quantitative measurements of their performance through a reader study with two medical experts who rated the quality of the synthesized images in three categories: Realistic image appearance, anatomical correctness and consistency between slices. Furthermore, we demonstrate that synthetic images can be used in a self-supervised pre-training and improve the performance of breast segmentation models when data is scarce (dice score 0.91 vs. 0.95 without vs. with synthetic data).

运行时执行是指针对运行时正式规范执行正确行为的理论，技术和工具。在本文中，我们对用于构建AI中执行安全性的混凝土应用程序域的运行时执行器的技术感兴趣。我们讨论了传统上如何在AI领域处理安全性，以及如何通过集成运行时执行器来提供自我学习代理的安全性。我们调查了此类执法者的一系列工作，在该工作中，我们区分了离散和连续动作空间的方法。本文的目的是更好地理解不同执法技术的优势和局限性，重点关注由于AI在AI中的应用而引起的特定挑战。最后，我们为未来的工作提出了一些开放的挑战和途径。