剪切粘度虽然是所有液体的基本特性，但在计算上估计分子动力学模拟的计算昂贵。最近，机器学习（ML）方法已被用于在许多情况下增强分子模拟，从而显示出以相对廉价的方式估算粘度的希望。但是，ML方法面临重大挑战，例如当数据集的大小很小时，粘度也很小。在这项工作中，我们训练多个ML模型，以预测Lennard-Jones（LJ）流体的剪切粘度，特别强调解决由小型数据集引起的问题。具体而言，研究了与模型选择，绩效估计和不确定性定量有关的问题。首先，我们表明使用单个看不见的数据集的广泛使用的性能估计步骤显示了小数据集的广泛可变性。在这种情况下，可以使用交叉验证（CV）选择超参数（模型选择）的常见实践，以估算概括误差（性能估计）。我们比较了两个简单的简历程序，以便他们同时选择模型选择和性能估计的能力，并发现基于K折CV的过程显示出较低的误差估计差异。我们讨论绩效指标在培训和评估中的作用。最后，使用高斯工艺回归（GPR）和集合方法来估计单个预测的不确定性。 GPR的不确定性估计还用于构建适用性域，使用ML模型对本工作中生成的另一个小数据集提供了更可靠的预测。总体而言，这项工作中规定的程序共同导致了针对小型数据集的强大ML模型。

现实世界的面部表达识别（FER）数据集遭受吵闹的注释，由于众包，表达式的歧义，注释者的主观性和类间的相似性。但是，最近的深层网络具有强大的能力，可以记住嘈杂的注释导致腐蚀功能嵌入和泛化不良的能力。为了处理嘈杂的注释，我们提出了一个动态FER学习框架（DNFER），其中根据训练过程中的动态类特定阈值选择了干净的样品。具体而言，DNFER基于使用选定的干净样品和使用所有样品的无监督培训的监督培训。在训练过程中，每个微型批次的平均后类概率被用作动态类特异性阈值，以选择干净的样品进行监督训练。该阈值与噪声率无关，与其他方法不同，不需要任何干净的数据。此外，要从所有样品中学习，使用无监督的一致性损失对齐弱调节图像和强大图像之间的后验分布。我们证明了DNFER在合成和实际噪声注释的FER数据集（如RaFDB，Ferplus，Sfew和altimpnet）上的鲁棒性。

自动情感识别在许多领域都有应用，例如教育，游戏，软件开发，汽车，医疗保健等。但是，在野外数据集上实现可观的绩效是无琐的任务。野外数据集虽然比合成数据集更好地代表了现实世界中的情况，但前者遇到了不完整标签的问题。受到半监督学习的启发，在本文中，我们在第四次情感行为分析（ABAW）2022竞赛中介绍了提交的多任务学习挑战。在这项挑战中考虑的三个任务是价估计（VA）估计，表达式分为6个基本（愤怒，厌恶，恐惧，幸福，悲伤，惊喜），中立和“其他”类别和12个行动单位（au）编号au - \ {1,2,4,6,7,10,12,15,15,23,24,25,26 \}。我们的方法半监督的多任务面部情感情感识别标题为\ textbf {ss-mfar}使用一个深层残留网络，每个任务都具有特定任务分类器以及每个表达式类别的自适应阈值，每个表达式类别和半监督学习。源代码可从https://github.com/1980x/abaw202​​22dmacs获得。

我们专注于拥挤环境中的机器人导航。预测机器人周围人群的运动的挑战使得难以确保人类的安全和舒适。最近的方法通常采用端到端技术来进行机器人控制或深层体系结构，以进行高保真的人类运动预测。尽管这些方法在模拟域中获得了重要的性能基准，但数据集限制和较高的样本复杂性倾向于阻止它们转移到现实世界中。我们的关键见解是，捕获人群动力学的关键特征的低维表示可能足以使机器人能够平稳地绕过人群。为此，我们使用拓扑不变性的概念将数学上的行为正式化了两种代理作为旋转的行为。基于这种形式主义，我们设计了一个成本功能，有利于机器人轨迹促进更高的传球进展，并惩罚人之间不同方面的切换。我们将此功能纳入模型预测控制器中，该模型使用了人类运动预测的简单恒定速度模型。这导致机器人运动在统计学上与最先进的基线相比，在统计学上，在统计学上取得了显着更高的清除，同时保持竞争性效率水平，跨越广泛的模拟以及在自动平衡机器人上的现实世界实验。

Designing experiments often requires balancing between learning about the true treatment effects and earning from allocating more samples to the superior treatment. While optimal algorithms for the Multi-Armed Bandit Problem (MABP) provide allocation policies that optimally balance learning and earning, they tend to be computationally expensive. The Gittins Index (GI) is a solution to the MABP that can simultaneously attain optimality and computationally efficiency goals, and it has been recently used in experiments with Bernoulli and Gaussian rewards. For the first time, we present a modification of the GI rule that can be used in experiments with exponentially-distributed rewards. We report its performance in simulated 2- armed and 3-armed experiments. Compared to traditional non-adaptive designs, our novel GI modified design shows operating characteristics comparable in learning (e.g. statistical power) but substantially better in earning (e.g. direct benefits). This illustrates the potential that designs using a GI approach to allocate participants have to improve participant benefits, increase efficiencies, and reduce experimental costs in adaptive multi-armed experiments with exponential rewards.

Quadruped robots are currently used in industrial robotics as mechanical aid to automate several routine tasks. However, presently, the usage of such a robot in a domestic setting is still very much a part of the research. This paper discusses the understanding and virtual simulation of such a robot capable of detecting and understanding human emotions, generating its gait, and responding via sounds and expression on a screen. To this end, we use a combination of reinforcement learning and software engineering concepts to simulate a quadruped robot that can understand emotions, navigate through various terrains and detect sound sources, and respond to emotions using audio-visual feedback. This paper aims to establish the framework of simulating a quadruped robot that is emotionally intelligent and can primarily respond to audio-visual stimuli using motor or audio response. The emotion detection from the speech was not as performant as ERANNs or Zeta Policy learning, still managing an accuracy of 63.5%. The video emotion detection system produced results that are almost at par with the state of the art, with an accuracy of 99.66%. Due to its "on-policy" learning process, the PPO algorithm was extremely rapid to learn, allowing the simulated dog to demonstrate a remarkably seamless gait across the different cadences and variations. This enabled the quadruped robot to respond to generated stimuli, allowing us to conclude that it functions as predicted and satisfies the aim of this work.

Real-world robotic grasping can be done robustly if a complete 3D Point Cloud Data (PCD) of an object is available. However, in practice, PCDs are often incomplete when objects are viewed from few and sparse viewpoints before the grasping action, leading to the generation of wrong or inaccurate grasp poses. We propose a novel grasping strategy, named 3DSGrasp, that predicts the missing geometry from the partial PCD to produce reliable grasp poses. Our proposed PCD completion network is a Transformer-based encoder-decoder network with an Offset-Attention layer. Our network is inherently invariant to the object pose and point's permutation, which generates PCDs that are geometrically consistent and completed properly. Experiments on a wide range of partial PCD show that 3DSGrasp outperforms the best state-of-the-art method on PCD completion tasks and largely improves the grasping success rate in real-world scenarios. The code and dataset will be made available upon acceptance.

When robots learn reward functions using high capacity models that take raw state directly as input, they need to both learn a representation for what matters in the task -- the task ``features" -- as well as how to combine these features into a single objective. If they try to do both at once from input designed to teach the full reward function, it is easy to end up with a representation that contains spurious correlations in the data, which fails to generalize to new settings. Instead, our ultimate goal is to enable robots to identify and isolate the causal features that people actually care about and use when they represent states and behavior. Our idea is that we can tune into this representation by asking users what behaviors they consider similar: behaviors will be similar if the features that matter are similar, even if low-level behavior is different; conversely, behaviors will be different if even one of the features that matter differs. This, in turn, is what enables the robot to disambiguate between what needs to go into the representation versus what is spurious, as well as what aspects of behavior can be compressed together versus not. The notion of learning representations based on similarity has a nice parallel in contrastive learning, a self-supervised representation learning technique that maps visually similar data points to similar embeddings, where similarity is defined by a designer through data augmentation heuristics. By contrast, in order to learn the representations that people use, so we can learn their preferences and objectives, we use their definition of similarity. In simulation as well as in a user study, we show that learning through such similarity queries leads to representations that, while far from perfect, are indeed more generalizable than self-supervised and task-input alternatives.

and widely used information measurement metric, particularly popularized for SSVEP- based Brain-Computer (BCI) interfaces. By combining speed and accuracy into a single-valued parameter, this metric aids in the evaluation and comparison of various target identification algorithms across different BCI communities. To accurately depict performance and inspire an end-to-end design for futuristic BCI designs, a more thorough examination and definition of ITR is therefore required. We model the symbiotic communication medium, hosted by the retinogeniculate visual pathway, as a discrete memoryless channel and use the modified capacity expressions to redefine the ITR. We use graph theory to characterize the relationship between the asymmetry of the transition statistics and the ITR gain with the new definition, leading to potential bounds on data rate performance. On two well-known SSVEP datasets, we compared two cutting-edge target identification methods. Results indicate that the induced DM channel asymmetry has a greater impact on the actual perceived ITR than the change in input distribution. Moreover, it is demonstrated that the ITR gain under the new definition is inversely correlated with the asymmetry in the channel transition statistics. Individual input customizations are further shown to yield perceived ITR performance improvements. An algorithm is proposed to find the capacity of binary classification and further discussions are given to extend such results to ensemble techniques.We anticipate that the results of our study will contribute to the characterization of the highly dynamic BCI channel capacities, performance thresholds, and improved BCI stimulus designs for a tighter symbiosis between the human brain and computer systems while enhancing the efficiency of the underlying communication resources.

A step-search sequential quadratic programming method is proposed for solving nonlinear equality constrained stochastic optimization problems. It is assumed that constraint function values and derivatives are available, but only stochastic approximations of the objective function and its associated derivatives can be computed via inexact probabilistic zeroth- and first-order oracles. Under reasonable assumptions, a high-probability bound on the iteration complexity of the algorithm to approximate first-order stationarity is derived. Numerical results on standard nonlinear optimization test problems illustrate the advantages and limitations of our proposed method.