由于数据保护法和机构内的官方程序,在实践中很难在机构之间共享医疗数据。因此,大多数现有的算法经过相对较小的脑电图(EEG)数据集的培训,这可能会损害预测准确性。在这项工作中,我们通过将公开可用的数据集分配到代表各个机构中数据的不相交集中来共享数据时模拟了一个情况。我们建议在每个机构中培训一个(本地)检测器,并将其个人预测汇总为最终预测。比较了四个集合计划,即多数投票,平均值,加权平均值和Dawid-Skene方法。该方法仅使用EEG通道的一个子集在独立的数据集上进行了验证。当每个机构提供足够数量的数据时,合奏的精度与对所有数据进行训练的单个检测器相当。加权平均聚合方案表现出最佳性能,当局部检测器接近对所有可用数据训练的单个检测器的性能时,它只能用DAWID-SKENE方法略有优于。
translated by 谷歌翻译
Compliance in actuation has been exploited to generate highly dynamic maneuvers such as throwing that take advantage of the potential energy stored in joint springs. However, the energy storage and release could not be well-timed yet. On the contrary, for multi-link systems, the natural system dynamics might even work against the actual goal. With the introduction of variable stiffness actuators, this problem has been partially addressed. With a suitable optimal control strategy, the approximate decoupling of the motor from the link can be achieved to maximize the energy transfer into the distal link prior to launch. However, such continuous stiffness variation is complex and typically leads to oscillatory swing-up motions instead of clear launch sequences. To circumvent this issue, we investigate decoupling for speed maximization with a dedicated novel actuator concept denoted Bi-Stiffness Actuation. With this, it is possible to fully decouple the link from the joint mechanism by a switch-and-hold clutch and simultaneously keep the elastic energy stored. We show that with this novel paradigm, it is not only possible to reach the same optimal performance as with power-equivalent variable stiffness actuation, but even directly control the energy transfer timing. This is a major step forward compared to previous optimal control approaches, which rely on optimizing the full time-series control input.
translated by 谷歌翻译
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.
translated by 谷歌翻译
近年来,由于深度学习体系结构的有希望的进步,面部识别系统取得了非凡的成功。但是,当将配置图像与额叶图像的画廊匹配时,它们仍然无法实现预期的准确性。当前方法要么执行姿势归一化(即额叶化)或脱离姿势信息以进行面部识别。相反,我们提出了一种新方法,通过注意机制将姿势用作辅助信息。在本文中,我们假设使用注意机制姿势参加的信息可以指导剖面面上的上下文和独特的特征提取,从而进一步使嵌入式域中的更好表示形式学习。为了实现这一目标,首先,我们设计了一个统一的耦合曲线到额定面部识别网络。它通过特定于类的对比损失来学习从面孔到紧凑的嵌入子空间的映射。其次,我们开发了一个新颖的姿势注意力块(PAB),以专门指导从剖面面上提取姿势 - 不合稳定的特征。更具体地说,PAB旨在显式地帮助网络沿着频道和空间维度沿着频道和空间维度的重要特征,同时学习嵌入式子空间中的歧视性但构成不变的特征。为了验证我们提出的方法的有效性,我们对包括多PIE,CFP,IJBC在内的受控和野生基准进行实验,并在艺术状态下表现出优势。
translated by 谷歌翻译
在本文中,我们试图在抽象嵌入空间中绘制额叶和轮廓面图像之间的连接。我们使用耦合编码器网络利用此连接将额叶/配置文件的面部图像投影到一个常见的潜在嵌入空间中。提出的模型通过最大化面部两种视图之间的相互信息来迫使嵌入空间中表示的相似性。拟议的耦合编码器从三个贡献中受益于与极端姿势差异的匹配面。首先,我们利用我们的姿势意识到的对比学习来最大程度地提高身份额叶和概况表示之间的相互信息。其次,由在过去的迭代中积累的潜在表示组成的内存缓冲区已集成到模型中,因此它可以比小批量大小相对较多的实例。第三,一种新颖的姿势感知的对抗结构域适应方法迫使模型学习从轮廓到额叶表示的不对称映射。在我们的框架中,耦合编码器学会了扩大真实面孔和冒名顶替面部分布之间的边距,这导致了相同身份的不同观点之间的高度相互信息。通过对四个基准数据集的广泛实验,评估和消融研究来研究拟议模型的有效性,并与引人入胜的最新算法进行比较。
translated by 谷歌翻译
目的:开发和验证一种自动化方法,用于对新生儿重症监护病房中睡眠状态波动的床旁监测。方法:基于深度学习的算法是使用30个近期新生儿的长期(a)脑电图监测的53个EEG录音设计和训练的。使用来自30个多摄影记录的外部数据集对结果进行了验证。除了训练和验证单个脑电图通道安静的睡眠探测器外,我们还构建了睡眠状态趋势(SST),这是一种可视化分类器输出的床旁准备手段。结果:训练数据中安静的睡眠检测的准确性为90%,在4电极记录中获得的所有双极派生中,精度是可比的(85-86%)。该算法很好地概括了外部数据集,尽管信号推导不同,但仍显示81%的总体精度。 SST允许对分类器输出的直观,清晰可视化。结论:可以从单个EEG通道的高保真度中检测到睡眠状态的波动,并且可以将结果可视化为床边监视器中透明和直观的趋势。意义:睡眠状态趋势(SST)可以为护理人员提供对睡眠状态波动及其周期性的实时视图。
translated by 谷歌翻译
神经网络可以从单个图像中了解视觉世界的内容是什么?虽然它显然不能包含存在的可能对象,场景和照明条件 - 在所有可能的256 ^(3x224x224)224尺寸的方形图像中,它仍然可以在自然图像之前提供强大的。为了分析这一假设,我们通过通过监控掠夺教师的知识蒸馏来制定一种训练神经网络的培训神经网络。有了这个,我们发现上述问题的答案是:“令人惊讶的是,很多”。在定量术语中,我们在CiFar-10/100上找到了94%/ 74%的前1个精度,在想象中,通过将这种方法扩展到音频,84%的语音组合。在广泛的分析中,我们解除了增强,源图像和网络架构的选择,以及在从未见过熊猫的网络中发现“熊猫神经元”。这项工作表明,一个图像可用于推断成千上万的对象类,并激励关于增强和图像的基本相互作用的更新的研究议程。
translated by 谷歌翻译
Objective: Traumatic brain injury can be caused by head impacts, but many brain injury risk estimation models are not equally accurate across the variety of impacts that patients may undergo and the characteristics of different types of impacts are not well studied. We investigated the spectral characteristics of different head impact types with kinematics classification. Methods: Data was analyzed from 3,262 head impacts from lab reconstruction, American football, mixed martial arts, and publicly available car crash data. A random forest classifier with spectral densities of linear acceleration and angular velocity was built to classify head impact types (e.g., football, car crash, mixed martial arts). To test the classifier robustness, another 271 lab-reconstructed impacts were obtained from 5 other instrumented mouthguards. Finally, with the classifier, type-specific, nearest-neighbor regression models were built for brain strain. Results: The classifier reached a median accuracy of 96% over 1,000 random partitions of training and test sets. The most important features in the classification included both low-frequency and high-frequency features, both linear acceleration features and angular velocity features. Different head impact types had different distributions of spectral densities in low-frequency and high-frequency ranges (e.g., the spectral densities of MMA impacts were higher in high-frequency range than in the low-frequency range). The type-specific regression showed a generally higher R^2-value than baseline models without classification. Conclusion: The machine-learning-based classifier enables a better understanding of the impact kinematics spectral density in different sports, and it can be applied to evaluate the quality of impact-simulation systems and on-field data augmentation.
translated by 谷歌翻译
The recent increase in public and academic interest in preserving biodiversity has led to the growth of the field of conservation technology. This field involves designing and constructing tools that utilize technology to aid in the conservation of wildlife. In this article, we will use case studies to demonstrate the importance of designing conservation tools with human-wildlife interaction in mind and provide a framework for creating successful tools. These case studies include a range of complexities, from simple cat collars to machine learning and game theory methodologies. Our goal is to introduce and inform current and future researchers in the field of conservation technology and provide references for educating the next generation of conservation technologists. Conservation technology not only has the potential to benefit biodiversity but also has broader impacts on fields such as sustainability and environmental protection. By using innovative technologies to address conservation challenges, we can find more effective and efficient solutions to protect and preserve our planet's resources.
translated by 谷歌翻译
We present the interpretable meta neural ordinary differential equation (iMODE) method to rapidly learn generalizable (i.e., not parameter-specific) dynamics from trajectories of multiple dynamical systems that vary in their physical parameters. The iMODE method learns meta-knowledge, the functional variations of the force field of dynamical system instances without knowing the physical parameters, by adopting a bi-level optimization framework: an outer level capturing the common force field form among studied dynamical system instances and an inner level adapting to individual system instances. A priori physical knowledge can be conveniently embedded in the neural network architecture as inductive bias, such as conservative force field and Euclidean symmetry. With the learned meta-knowledge, iMODE can model an unseen system within seconds, and inversely reveal knowledge on the physical parameters of a system, or as a Neural Gauge to "measure" the physical parameters of an unseen system with observed trajectories. We test the validity of the iMODE method on bistable, double pendulum, Van der Pol, Slinky, and reaction-diffusion systems.
translated by 谷歌翻译