阿尔茨海默氏病（AD）是痴呆症的最常见形式，由于痴呆症的多因素病因，通常难以诊断。关于基于神经成像的基于神经成像的深度神经网络（DNN）的著作表明，结构磁共振图像（SMRI）和氟脱氧葡萄糖正电子发射层析成像（FDG-PET）可提高健康对照和受试者的研究人群的精度。与广告。但是，这一结果与既定的临床知识冲突，即FDG-PET比SMRI更好地捕获AD特定的病理。因此，我们提出了一个框架，用于对基于FDG-PET和SMRI进行多模式DNN的系统评估，并重新评估单模式DNN和多模式DNN，用于二进制健康与AD，以及三向健康/轻度的健康/轻度认知障碍/广告分类。我们的实验表明，使用FDG-PET的单模式网络的性能优于MRI（准确性0.91 vs 0.87），并且在组合时不会显示出改进。这符合有关AD生物标志物的既定临床知识，但提出了有关多模式DNN的真正好处的问题。我们认为，未来关于多模式融合的工作应系统地评估我们提出的评估框架后的个人模式的贡献。最后，我们鼓励社区超越健康与AD分类，并专注于痴呆症的鉴别诊断，在这种诊断中，在这种诊断中，融合了多模式图像信息与临床需求相符。

对皮层结构的时间变化进行建模对于更好地理解阿尔茨海默氏病（AD）的进展至关重要。鉴于它们灵活地适应了异质序列的长度，过去已经提出了基于网格的变压器体系结构，以预测跨时间的海马变形。但是，变压器的主要局限性之一是大量可训练的参数，这使小型数据集上的应用程序非常具有挑战性。此外，当前方法不包括相关的非图像信息，这些信息可以帮助识别进展中与AD相关的模式。为此，我们介绍了CashFormer，这是一种基于变压器的框架，以模拟AD中的纵向形状轨迹。 CashFormer将预先训练的变压器作为通用计算引擎的想法，通过在微调过程中冻结大多数层来跨越各种任务。相对于原始模型，这将参数的数量减少了90％以上，因此可以在小型数据集中应用大型模型而不会过度拟合。此外，CashFormer模型的认知能力下降以揭示时间序列中的AD萎缩模式。我们的结果表明，与先前提出的方法相比，现金形式的重建误差降低了73％。此外，随着缺失的纵向形状数据，检测到AD的患者的准确性增加了3％。

我们提出了一种无监督的域适应（UDA）方法，用于白质超强度（WMH）分割，其使用具有不确定性依赖标签改进的自我训练（果馅乳头）。最近被引入自我培训作为UDA的高效方法，这是基于自我产生的伪标签。但是，伪标签可能非常嘈杂，因此模型性能恶化。我们建议预测伪标签的不确定性，并将其整合在培训过程中，以不确定性导向的损失功能来突出以高确定性突出标签。通过在伪标签生成中结合现有方法的分割输出，进一步改善了馅馅乳头片，其显示为WMH分割的高稳健性。在我们的实验中，我们评估具有标准U-Net和具有更高接受领域的修改网络的批发力。我们的结果在数据集中的WMH分割展示了标准自我训练方面的恒星的显着改善。

Robotic teleoperation is a key technology for a wide variety of applications. It allows sending robots instead of humans in remote, possibly dangerous locations while still using the human brain with its enormous knowledge and creativity, especially for solving unexpected problems. A main challenge in teleoperation consists of providing enough feedback to the human operator for situation awareness and thus create full immersion, as well as offering the operator suitable control interfaces to achieve efficient and robust task fulfillment. We present a bimanual telemanipulation system consisting of an anthropomorphic avatar robot and an operator station providing force and haptic feedback to the human operator. The avatar arms are controlled in Cartesian space with a direct mapping of the operator movements. The measured forces and torques on the avatar side are haptically displayed to the operator. We developed a predictive avatar model for limit avoidance which runs on the operator side, ensuring low latency. The system was successfully evaluated during the ANA Avatar XPRIZE competition semifinals. In addition, we performed in lab experiments and carried out a small user study with mostly untrained operators.

The purpose of this work was to tackle practical issues which arise when using a tendon-driven robotic manipulator with a long, passive, flexible proximal section in medical applications. A separable robot which overcomes difficulties in actuation and sterilization is introduced, in which the body containing the electronics is reusable and the remainder is disposable. A control input which resolves the redundancy in the kinematics and a physical interpretation of this redundancy are provided. The effect of a static change in the proximal section angle on bending angle error was explored under four testing conditions for a sinusoidal input. Bending angle error increased for increasing proximal section angle for all testing conditions with an average error reduction of 41.48% for retension, 4.28% for hysteresis, and 52.35% for re-tension + hysteresis compensation relative to the baseline case. Two major sources of error in tracking the bending angle were identified: time delay from hysteresis and DC offset from the proximal section angle. Examination of these error sources revealed that the simple hysteresis compensation was most effective for removing time delay and re-tension compensation for removing DC offset, which was the primary source of increasing error. The re-tension compensation was also tested for dynamic changes in the proximal section and reduced error in the final configuration of the tip by 89.14% relative to the baseline case.

Learning enabled autonomous systems provide increased capabilities compared to traditional systems. However, the complexity of and probabilistic nature in the underlying methods enabling such capabilities present challenges for current systems engineering processes for assurance, and test, evaluation, verification, and validation (TEVV). This paper provides a preliminary attempt to map recently developed technical approaches in the assurance and TEVV of learning enabled autonomous systems (LEAS) literature to a traditional systems engineering v-model. This mapping categorizes such techniques into three main approaches: development, acquisition, and sustainment. We review the latest techniques to develop safe, reliable, and resilient learning enabled autonomous systems, without recommending radical and impractical changes to existing systems engineering processes. By performing this mapping, we seek to assist acquisition professionals by (i) informing comprehensive test and evaluation planning, and (ii) objectively communicating risk to leaders.

In inverse reinforcement learning (IRL), a learning agent infers a reward function encoding the underlying task using demonstrations from experts. However, many existing IRL techniques make the often unrealistic assumption that the agent has access to full information about the environment. We remove this assumption by developing an algorithm for IRL in partially observable Markov decision processes (POMDPs). We address two limitations of existing IRL techniques. First, they require an excessive amount of data due to the information asymmetry between the expert and the learner. Second, most of these IRL techniques require solving the computationally intractable forward problem -- computing an optimal policy given a reward function -- in POMDPs. The developed algorithm reduces the information asymmetry while increasing the data efficiency by incorporating task specifications expressed in temporal logic into IRL. Such specifications may be interpreted as side information available to the learner a priori in addition to the demonstrations. Further, the algorithm avoids a common source of algorithmic complexity by building on causal entropy as the measure of the likelihood of the demonstrations as opposed to entropy. Nevertheless, the resulting problem is nonconvex due to the so-called forward problem. We solve the intrinsic nonconvexity of the forward problem in a scalable manner through a sequential linear programming scheme that guarantees to converge to a locally optimal policy. In a series of examples, including experiments in a high-fidelity Unity simulator, we demonstrate that even with a limited amount of data and POMDPs with tens of thousands of states, our algorithm learns reward functions and policies that satisfy the task while inducing similar behavior to the expert by leveraging the provided side information.

Speech-driven 3D facial animation has been widely explored, with applications in gaming, character animation, virtual reality, and telepresence systems. State-of-the-art methods deform the face topology of the target actor to sync the input audio without considering the identity-specific speaking style and facial idiosyncrasies of the target actor, thus, resulting in unrealistic and inaccurate lip movements. To address this, we present Imitator, a speech-driven facial expression synthesis method, which learns identity-specific details from a short input video and produces novel facial expressions matching the identity-specific speaking style and facial idiosyncrasies of the target actor. Specifically, we train a style-agnostic transformer on a large facial expression dataset which we use as a prior for audio-driven facial expressions. Based on this prior, we optimize for identity-specific speaking style based on a short reference video. To train the prior, we introduce a novel loss function based on detected bilabial consonants to ensure plausible lip closures and consequently improve the realism of the generated expressions. Through detailed experiments and a user study, we show that our approach produces temporally coherent facial expressions from input audio while preserving the speaking style of the target actors.

We study the problem of graph clustering under a broad class of objectives in which the quality of a cluster is defined based on the ratio between the number of edges in the cluster, and the total weight of vertices in the cluster. We show that our definition is closely related to popular clustering measures, namely normalized associations, which is a dual of the normalized cut objective, and normalized modularity. We give a linear time constant-approximate algorithm for our objective, which implies the first constant-factor approximation algorithms for normalized modularity and normalized associations.

Neuromorphic systems require user-friendly software to support the design and optimization of experiments. In this work, we address this need by presenting our development of a machine learning-based modeling framework for the BrainScaleS-2 neuromorphic system. This work represents an improvement over previous efforts, which either focused on the matrix-multiplication mode of BrainScaleS-2 or lacked full automation. Our framework, called hxtorch.snn, enables the hardware-in-the-loop training of spiking neural networks within PyTorch, including support for auto differentiation in a fully-automated hardware experiment workflow. In addition, hxtorch.snn facilitates seamless transitions between emulating on hardware and simulating in software. We demonstrate the capabilities of hxtorch.snn on a classification task using the Yin-Yang dataset employing a gradient-based approach with surrogate gradients and densely sampled membrane observations from the BrainScaleS-2 hardware system.