为了引导电子商务用户进行购买，营销人员依靠对用户何时退出而无需购买的预测。以前，此类预测是基于隐藏的马尔可夫模型（HMM），因为它们具有不同用户意图的潜在购物阶段建模的能力。在这项工作中，我们开发了持续时间依赖的隐藏马尔可夫模型。与传统的HMM相反，它明确地对潜在状态的持续时间进行了建模，从而使国家变得“粘性”。提出的模型在检测用户退出时优于先前的HMM：在不购买的100个用户退出中，它可以正确识别另外18个。这可以帮助营销人员更好地管理电子商务客户的在线行为。我们模型卓越性能的原因是持续时间依赖性，这使我们的模型能够恢复以扭曲时间感的特征的潜在状态。我们最终为此提供了理论上的解释，该解释基于“流”的概念。

利用来自多个域的标记数据来启用没有标签的另一个域中的预测是一个重大但充满挑战的问题。为了解决这个问题，我们介绍了框架Dapdag（\ textbf {d} omain \ textbf {a}通过\ textbf {p} daptation daptation daptation \ textbf {p} erturbed \ textbf {dag}重建），并建议学习对人群进行投入的自动化统计信息给定特征并重建有向的无环图（DAG）作为辅助任务。在观察到的变量中，允许有条件的分布在由潜在环境变量$ e $领导的域变化的变量中，假定基础DAG结构不变。编码器旨在用作$ e $的推理设备，而解码器重建每个观察到的变量，以其DAG中的图形父母和推断的$ e $进行。我们以端到端的方式共同训练编码器和解码器，并对具有混合变量的合成和真实数据集进行实验。经验结果表明，重建DAG有利于近似推断。此外，我们的方法可以在预测任务中与其他基准测试实现竞争性能，具有更好的适应能力，尤其是在目标领域与源域显着不同的目标领域。

估算观察数据的个性化治疗效果（ITES）对于决策至关重要。为了获得非偏见的ITE估计，常见的假设是所有混杂因素都被观察到。然而，在实践中，我们不太可能直接观察这些混乱。相反，我们经常遵守真正的混乱的噪音测量，这可以作为有效代理。在本文中，我们解决了在观察嘈杂的代理而不是真正的混乱中估算ITE的问题。为此，我们开发了一种Deconfound Temporal AutoEncoder，这是一种利用观察到嘈杂的代理来学习反映真正隐藏的混淆的隐藏嵌入的新方法。特别地，DTA将长短期存储器自动统计器组合出具有因果正则化惩罚，该惩罚使得有条件独立于所学习的隐藏嵌入的潜在结果和治疗分配。通过DTA学习隐藏的嵌入后，最先进的结果模型可用于控制它并获得ITE的无偏见估计。使用综合性和现实世界的医疗数据，我们通过通过大幅保证金改善最先进的基准来证明我们的DTA的有效性。

学习概括目标人口的个性化决定政策具有很大的相关性。由于培训数据往往没有代表目标人群，因此标准政策学习方法可以产生不概括目标人群的政策。为了解决这一挑战，我们提出了一种新颖的框架，用于学习概括目标人口的政策。为此，我们将训练数据和目标群体之间的差异描述为使用选择变量的采样选择偏差。在此选择变量周围设置的不确定性，我们优化了策略的最低限度值，以实现目标人口的最佳案例策略值。为了解决Minimax问题，我们基于凸凹过程推出了一种高效的算法，并证明了对逻辑策略等策略的参数化空间的收敛性。我们证明，如果不确定性集被详细说明，我们的政策会推广到目标人口，因为它们不能比培训数据更糟糕。使用模拟数据和临床试验，我们证明，与标准政策学习方法相比，我们的框架大大提高了政策的普遍性。

The release of ChatGPT, a language model capable of generating text that appears human-like and authentic, has gained significant attention beyond the research community. We expect that the convincing performance of ChatGPT incentivizes users to apply it to a variety of downstream tasks, including prompting the model to simplify their own medical reports. To investigate this phenomenon, we conducted an exploratory case study. In a questionnaire, we asked 15 radiologists to assess the quality of radiology reports simplified by ChatGPT. Most radiologists agreed that the simplified reports were factually correct, complete, and not potentially harmful to the patient. Nevertheless, instances of incorrect statements, missed key medical findings, and potentially harmful passages were reported. While further studies are needed, the initial insights of this study indicate a great potential in using large language models like ChatGPT to improve patient-centered care in radiology and other medical domains.

In recent years, several metrics have been developed for evaluating group fairness of rankings. Given that these metrics were developed with different application contexts and ranking algorithms in mind, it is not straightforward which metric to choose for a given scenario. In this paper, we perform a comprehensive comparative analysis of existing group fairness metrics developed in the context of fair ranking. By virtue of their diverse application contexts, we argue that such a comparative analysis is not straightforward. Hence, we take an axiomatic approach whereby we design a set of thirteen properties for group fairness metrics that consider different ranking settings. A metric can then be selected depending on whether it satisfies all or a subset of these properties. We apply these properties on eleven existing group fairness metrics, and through both empirical and theoretical results we demonstrate that most of these metrics only satisfy a small subset of the proposed properties. These findings highlight limitations of existing metrics, and provide insights into how to evaluate and interpret different fairness metrics in practical deployment. The proposed properties can also assist practitioners in selecting appropriate metrics for evaluating fairness in a specific application.

In recent years distributional reinforcement learning has produced many state of the art results. Increasingly sample efficient Distributional algorithms for the discrete action domain have been developed over time that vary primarily in the way they parameterize their approximations of value distributions, and how they quantify the differences between those distributions. In this work we transfer three of the most well-known and successful of those algorithms (QR-DQN, IQN and FQF) to the continuous action domain by extending two powerful actor-critic algorithms (TD3 and SAC) with distributional critics. We investigate whether the relative performance of the methods for the discrete action space translates to the continuous case. To that end we compare them empirically on the pybullet implementations of a set of continuous control tasks. Our results indicate qualitative invariance regarding the number and placement of distributional atoms in the deterministic, continuous action setting.

Artificial Intelligence (AI) has become commonplace to solve routine everyday tasks. Because of the exponential growth in medical imaging data volume and complexity, the workload on radiologists is steadily increasing. We project that the gap between the number of imaging exams and the number of expert radiologist readers required to cover this increase will continue to expand, consequently introducing a demand for AI-based tools that improve the efficiency with which radiologists can comfortably interpret these exams. AI has been shown to improve efficiency in medical-image generation, processing, and interpretation, and a variety of such AI models have been developed across research labs worldwide. However, very few of these, if any, find their way into routine clinical use, a discrepancy that reflects the divide between AI research and successful AI translation. To address the barrier to clinical deployment, we have formed MONAI Consortium, an open-source community which is building standards for AI deployment in healthcare institutions, and developing tools and infrastructure to facilitate their implementation. This report represents several years of weekly discussions and hands-on problem solving experience by groups of industry experts and clinicians in the MONAI Consortium. We identify barriers between AI-model development in research labs and subsequent clinical deployment and propose solutions. Our report provides guidance on processes which take an imaging AI model from development to clinical implementation in a healthcare institution. We discuss various AI integration points in a clinical Radiology workflow. We also present a taxonomy of Radiology AI use-cases. Through this report, we intend to educate the stakeholders in healthcare and AI (AI researchers, radiologists, imaging informaticists, and regulators) about cross-disciplinary challenges and possible solutions.

Heating in private households is a major contributor to the emissions generated today. Heat pumps are a promising alternative for heat generation and are a key technology in achieving our goals of the German energy transformation and to become less dependent on fossil fuels. Today, the majority of heat pumps in the field are controlled by a simple heating curve, which is a naive mapping of the current outdoor temperature to a control action. A more advanced control approach is model predictive control (MPC) which was applied in multiple research works to heat pump control. However, MPC is heavily dependent on the building model, which has several disadvantages. Motivated by this and by recent breakthroughs in the field, this work applies deep reinforcement learning (DRL) to heat pump control in a simulated environment. Through a comparison to MPC, it could be shown that it is possible to apply DRL in a model-free manner to achieve MPC-like performance. This work extends other works which have already applied DRL to building heating operation by performing an in-depth analysis of the learned control strategies and by giving a detailed comparison of the two state-of-the-art control methods.

In this paper, we present a modular methodology that combines state-of-the-art methods in (stochastic) machine learning with traditional methods in rule learning to provide efficient and scalable algorithms for the classification of vast data sets, while remaining explainable. Apart from evaluating our approach on the common large scale data sets MNIST, Fashion-MNIST and IMDB, we present novel results on explainable classifications of dental bills. The latter case study stems from an industrial collaboration with Allianz Private Krankenversicherungs-Aktiengesellschaft which is an insurance company offering diverse services in Germany.