Infomap是一种流行的方法，用于检测网络中节点的密度连接的“社区”。要检测此类社区，它建立在标准类型的马尔可夫链和信息理论中的想法。通过在网络上传播的疾病动态的动机，其节点可能具有异质疾病脱模速率，我们将Infomap扩展到吸收随机散步。为此，我们使用吸收缩放的图形，其中边缘权重根据吸收率缩放，以及马尔可夫时间扫描。我们的Infomap的一个扩展之一会聚到Infomap的标准版本，其中吸收率接近$ 0 $。我们发现，使用我们的Infomap扩展检测的社区结构可以从社区结构中显着不同，即一个使用不考虑节点吸收率的方法检测。此外，我们表明，局部动态引起的社区结构可以对环形格网络上的敏感感染恢复（SIR）动力学产生重要意义。例如，我们发现在适度数量的节点具有大的节点吸收率时，爆发持续时间最大化的情况。我们还使用我们的Infomap扩展来研究性接触网络中的社区结构。我们认为社区结构，与网络中无家可归者的不同吸收率相对应，以及对网络上的梅毒动力学的相关影响。我们观察到，当无家可归者人口中的治疗率低于其他人群时，当治疗率较低时，最终爆发规模可能会比其他人口相同。

Recently, Person Re-Identification (Re-ID) has received a lot of attention. Large datasets containing labeled images of various individuals have been released, allowing researchers to develop and test many successful approaches. However, when such Re-ID models are deployed in new cities or environments, the task of searching for people within a network of security cameras is likely to face an important domain shift, thus resulting in decreased performance. Indeed, while most public datasets were collected in a limited geographic area, images from a new city present different features (e.g., people's ethnicity and clothing style, weather, architecture, etc.). In addition, the whole frames of the video streams must be converted into cropped images of people using pedestrian detection models, which behave differently from the human annotators who created the dataset used for training. To better understand the extent of this issue, this paper introduces a complete methodology to evaluate Re-ID approaches and training datasets with respect to their suitability for unsupervised deployment for live operations. This method is used to benchmark four Re-ID approaches on three datasets, providing insight and guidelines that can help to design better Re-ID pipelines in the future.

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.

A link stream is a set of triplets $(t, u, v)$ indicating that $u$ and $v$ interacted at time $t$. Link streams model numerous datasets and their proper study is crucial in many applications. In practice, raw link streams are often aggregated or transformed into time series or graphs where decisions are made. Yet, it remains unclear how the dynamical and structural information of a raw link stream carries into the transformed object. This work shows that it is possible to shed light into this question by studying link streams via algebraically linear graph and signal operators, for which we introduce a novel linear matrix framework for the analysis of link streams. We show that, due to their linearity, most methods in signal processing can be easily adopted by our framework to analyze the time/frequency information of link streams. However, the availability of linear graph methods to analyze relational/structural information is limited. We address this limitation by developing (i) a new basis for graphs that allow us to decompose them into structures at different resolution levels; and (ii) filters for graphs that allow us to change their structural information in a controlled manner. By plugging-in these developments and their time-domain counterpart into our framework, we are able to (i) obtain a new basis for link streams that allow us to represent them in a frequency-structure domain; and (ii) show that many interesting transformations to link streams, like the aggregation of interactions or their embedding into a euclidean space, can be seen as simple filters in our frequency-structure domain.

Scenario-based probabilistic forecasts have become a vital tool to equip decision-makers to address the uncertain nature of renewable energies. To that end, this paper presents a recent promising deep learning generative approach called denoising diffusion probabilistic models. It is a class of latent variable models which have recently demonstrated impressive results in the computer vision community. However, to the best of our knowledge, there has yet to be a demonstration that they can generate high-quality samples of load, PV, or wind power time series, crucial elements to face the new challenges in power systems applications. Thus, we propose the first implementation of this model for energy forecasting using the open data of the Global Energy Forecasting Competition 2014. The results demonstrate this approach is competitive with other state-of-the-art deep learning generative models, including generative adversarial networks, variational autoencoders, and normalizing flows.

This work is on vision-based planning strategies for legged robots that separate locomotion planning into foothold selection and pose adaptation. Current pose adaptation strategies optimize the robot's body pose relative to given footholds. If these footholds are not reached, the robot may end up in a state with no reachable safe footholds. Therefore, we present a Vision-Based Terrain-Aware Locomotion (ViTAL) strategy that consists of novel pose adaptation and foothold selection algorithms. ViTAL introduces a different paradigm in pose adaptation that does not optimize the body pose relative to given footholds, but the body pose that maximizes the chances of the legs in reaching safe footholds. ViTAL plans footholds and poses based on skills that characterize the robot's capabilities and its terrain-awareness. We use the 90 kg HyQ and 140 kg HyQReal quadruped robots to validate ViTAL, and show that they are able to climb various obstacles including stairs, gaps, and rough terrains at different speeds and gaits. We compare ViTAL with a baseline strategy that selects the robot pose based on given selected footholds, and show that ViTAL outperforms the baseline.

生物学和人造药物需要处理现实世界中的不断变化。我们在四个经典的连续控制环境中研究了这个问题，并通过形态扰动增强。当不同身体部位的长度和厚度变化时，学习势头是挑战性的，因为需要控制政策才能适应形态以成功平衡和推进代理。我们表明，基于本体感受状态的控制策略的表现差，可以通过高度可变的身体配置，而（甲骨文）代理可以访问学习扰动的编码的（甲骨文）的性能要好得多。我们介绍了DMAP，这是一种以生物学启发的，基于注意力的策略网络体系结构。 DMAP将独立的本体感受处理，分布式策略与每个关节的单个控制器以及注意力机制结合在一起，从不同身体部位到不同控制器的动态门感觉信息。尽管无法访问（隐藏的）形态信息，但在所有考虑的环境中，DMAP都可以端对端训练，整体匹配或超越了Oracle代理的性能。因此，DMAP是从生物运动控制中实施原理的，为学习挑战的感觉运动任务提供了强烈的诱导偏见。总体而言，我们的工作证实了这些原则在挑战运动任务中的力量。

城市化及其问题需要对城市动态，尤其是现代城市复杂而多样化的生活方式的深入和全面的了解。数字化的数据可以准确捕获复杂的人类活动，但缺乏人口统计数据的解释性。在本文中，我们研究了美国11个都会区的120万人到110万个地方的出行探访模式的隐私增强数据集，以检测美国最大的美国城市中的潜在行动行为和生活方式。尽管出行访问的复杂性很大，但我们发现生活方式可以自动分解为12种潜在的可解释的活动行为，人们如何将购物，饮食，工作或利用空闲时间结合起来。我们没有描述具有单一生活方式的人，而是发现城市居民的行为是这些行为的混合。那些被检测到的潜在活动行为同样存在于城市之间，无法通过主要人口特征来完全解释。最后，我们发现这些潜在行为与在控制人口特征之后，即使在控制人口特征之后，这些潜在行为也与经验丰富的收入隔离，运输或健康行为有关。我们的结果表明，与活动行为相辅相成，以了解城市动态的重要性。

来自光场的大量空间和角度信息允许开发多种差异估计方法。但是，对光场的获取需要高存储和处理成本，从而限制了该技术在实际应用中的使用。为了克服这些缺点，压缩感应（CS）理论使光学体系结构的开发能够获得单个编码的光场测量。该测量是使用需要高计算成本的优化算法或深神经网络来解码的。从压缩光场进行的传统差异估计方法需要首先恢复整个光场，然后再恢复后处理步骤，从而需要长时间。相比之下，这项工作提出了通过省略传统方法所需的恢复步骤来从单个压缩测量中进行快速差异估计。具体而言，我们建议共同优化用于获取单个编码光场快照和卷积神经网络（CNN）的光学体系结构，以估计差异图。在实验上，提出的方法估计了与使用深度学习方法重建的光场相当的差异图。此外，所提出的方法在训练和推理方面的速度比估计重建光场差异的最佳方法要快20倍。

人重新识别（RE-ID）旨在在相机网络中寻找感兴趣的人（查询）。在经典的重新设置中，查询查询在包含整个身体的正确裁剪图像的画廊中。最近，引入了实时重新ID设置，以更好地代表Re-ID的实际应用上下文。它包括在简短的视频中搜索查询，其中包含整个场景帧。最初的实时重新ID基线使用行人探测器来构建大型搜索库和经典的重新ID模型，以在画廊中找到查询。但是，产生的画廊太大，包含低质量的图像，从而降低了现场重新ID性能。在这里，我们提出了一种称为贸易的新现场重新ID方法，以产生较低的高质量画廊。贸易首先使用跟踪算法来识别画廊中同一个人的图像序列。随后，使用异常检测模型选择每个轨道的单个良好代表。贸易已在PRID-2011数据集的实时重新ID版本上进行了验证，并显示出比基线的显着改进。