Traditionally, robots are regarded as universal motion generation machines. They are designed mainly by kinematics considerations while the desired dynamics is imposed by strong actuators and high-rate control loops. As an alternative, one can first consider the robot's intrinsic dynamics and optimize it in accordance with the desired tasks. Therefore, one needs to better understand intrinsic, uncontrolled dynamics of robotic systems. In this paper we focus on periodic orbits, as fundamental dynamic properties with many practical applications. Algebraic topology and differential geometry provide some fundamental statements about existence of periodic orbits. As an example, we present periodic orbits of the simplest multi-body system: the double-pendulum in gravity. This simple system already displays a rich variety of periodic orbits. We classify these into three classes: toroidal orbits, disk orbits and nonlinear normal modes. Some of these we found by geometrical insights and some by numerical simulation and sampling.
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腿部运动中的弹簧基于弹簧的执行器可提供能量效率和提高的性能,但增加了控制器设计的难度。尽管以前的作品集中在广泛的建模和模拟上,以找到此类系统的最佳控制器,但我们建议直接在真实机器人上学习无模型控制器。在我们的方法中,步态首先是由中央模式发电机(CPG)合成的,其参数被优化以快速获得可实现有效运动的开环控制器。然后,为了使该控制器更强大并进一步提高性能,我们使用强化学习来关闭循环,以在CPG之上学习纠正措施。我们评估了DLR弹性四足动物BERT中提出的方法。我们在学习小跑和前进步态方面的结果表明,对弹簧执行动力学的开发自然而然地从对动态运动的优化中出现,尽管没有模型,但仍会产生高性能的运动。整个过程在真正的机器人上不超过1.5小时,并导致自然步态。
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Sunquakes are seismic emissions visible on the solar surface, associated with some solar flares. Although discovered in 1998, they have only recently become a more commonly detected phenomenon. Despite the availability of several manual detection guidelines, to our knowledge, the astrophysical data produced for sunquakes is new to the field of Machine Learning. Detecting sunquakes is a daunting task for human operators and this work aims to ease and, if possible, to improve their detection. Thus, we introduce a dataset constructed from acoustic egression-power maps of solar active regions obtained for Solar Cycles 23 and 24 using the holography method. We then present a pedagogical approach to the application of machine learning representation methods for sunquake detection using AutoEncoders, Contrastive Learning, Object Detection and recurrent techniques, which we enhance by introducing several custom domain-specific data augmentation transformations. We address the main challenges of the automated sunquake detection task, namely the very high noise patterns in and outside the active region shadow and the extreme class imbalance given by the limited number of frames that present sunquake signatures. With our trained models, we find temporal and spatial locations of peculiar acoustic emission and qualitatively associate them to eruptive and high energy emission. While noting that these models are still in a prototype stage and there is much room for improvement in metrics and bias levels, we hypothesize that their agreement on example use cases has the potential to enable detection of weak solar acoustic manifestations.
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手动检查粪便涂片样品以鉴定寄生卵的存在非常耗时,只能由专家进行。因此,需要自动化系统来解决此问题,因为它可以与严重的肠道寄生虫感染有关。本文回顾了微观图像中关于寄生卵检测和分类的ICIP 2022挑战。我们描述了此应用程序的新数据集,该数据集是同类数据集的最大数据集。参与者在挑战中使用的方法及其结果及其结果进行了汇总和讨论。
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冠状质量弹出(CME)是最地理化的空间天气现象,与大型地磁风暴有关,有可能引起电信,卫星网络中断,电网损失和故障的干扰。因此,考虑到这些风暴对人类活动的潜在影响,对CME的地理效果的准确预测至关重要。这项工作着重于在接近太阳CME的白光冠状动脉数据集中训练的不同机器学习方法,以估计这种新爆发的弹出是否有可能诱导地磁活动。我们使用逻辑回归,k-nearest邻居,支持向量机,向前的人工神经网络以及整体模型开发了二进制分类模型。目前,我们限制了我们的预测专门使用太阳能发作参数,以确保延长警告时间。我们讨论了这项任务的主要挑战,即我们数据集中的地理填充和无效事件的数量以及它们的众多相似之处以及可用变量数量有限的极端失衡。我们表明,即使在这种情况下,这些模型也可以达到足够的命中率。
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除了固有的卵子因素外,孵化过程的质量影响了孵化速率的成功。消除不育或死鸡蛋以及监测胚胎生长是有效孵化场实践中非常重要的因素。该过程旨在对只有胚胎保留在孵化器中的卵进行分类,直到孵化过程结束。该过程旨在对胚胎进行分类,以保持孵化直到结束。最大检查是在孵化期的第一周完成。这项研究旨在检测卵中胚胎的存在并通过分割处理。使用基于实验室颜色图像的K均值算法对鸡蛋图像进行分割。图像采集的结果转换为实验室色彩空间图像。实验室颜色空间图像的结果是使用每种颜色的K-均值处理的。 K-均值过程使用群集K = 3并分为三个部分:背景,鸡蛋和蛋黄。蛋黄是具有胚胎特征的卵的一部分。这项研究在最初的阶段中应用了最初分割和灰度的颜色概念。初始阶段结果表明,基于实验室颜色空间的K均值聚类的图像分割结果提供了三个部分的分组。在灰度图像处理阶段,颜色图像分割的结果通过灰度,图像增强和形态处理。因此,很明显,蛋黄分段显示了卵子胚胎的存在。基于此结果,胚胎检测过程的初始阶段使用基于实验室颜色空间的K均值进行分割。该评估使用MSE和MSSIM,值为0.0486和0.9979;这可以用来引用所获得的结果可以检测到蛋黄中的胚胎。该方案可以用于对胚胎及其形态的非破坏性定量研究,以便将来在精确的家禽生产系统中。
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