元学习是机器学习的一个分支,旨在将相关任务分布的数据合成以有效地解决新的数据。在过程控制中,许多系统具有相似且充分理解的动力学,这表明可以通过元学习创建可推广的控制器是可行的。在这项工作中,我们制定了一种元加强学习(META-RL)控制策略,该策略利用已知的离线信息进行培训,例如模型结构。对模型参数的分布而不是单个模型,对元RL代理进行了训练,从而使代理能够自动适应过程动力学的变化,同时保持性能。一个关键的设计元素是能够在培训期间离线利用基于模型的信息,同时保持与新环境交互的无模型策略结构。我们以前的工作已经证明了如何将这种方法应用于调整比例综合控制器以控制一阶过程的与工业相关的问题。在这项工作中,我们简要地重新引入了我们的方法,并证明了如何将其扩展到比例综合衍生的控制器和二阶系统。
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元学习是机器学习的一个分支,它训练神经网络模型以合成各种数据,以快速解决新问题。在过程控制中,许多系统具有相似且充分理解的动力学,这表明可以通过元学习创建可推广的控制器是可行的。在这项工作中,我们制定了一种元加强学习(META-RL)控制策略,该策略可用于调整比例的整体控制器。我们的Meta-RL代理具有复发结构,该结构累积了“上下文”,以通过闭环中的隐藏状态变量学习系统的动力学。该体系结构使代理能够自动适应过程动力学的变化。在此处报告的测试中,对元RL代理完全离线训练了一阶和时间延迟系统,并从相同的训练过程动力学分布中得出的新型系统产生了出色的效果。一个关键的设计元素是能够在模拟环境中训练期间离线利用基于模型的信息,同时保持无模型的策略结构,以与真实过程动态不确定性的新过程进行交互。元学习是一种构建样品有效智能控制器的有前途的方法。
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深度加强学习(RL)是一种优化驱动的框架,用于生产一般动力系统的控制策略,而无明确依赖过程模型。仿真报告了良好的结果。在这里,我们展示了在真实物理系统上实现了艺术深度RL算法状态的挑战。方面包括软件与现有硬件之间的相互作用;实验设计和样品效率;培训受输入限制;和算法和控制法的解释性。在我们的方法中,我们的方法是使用PID控制器作为培训RL策略。除了简单性之外,这种方法还具有多种吸引力功能:无需将额外的硬件添加到控制系统中,因为PID控制器可以通过标准可编程逻辑控制器轻松实现;控制法可以在参数空间的“安全”区域中很容易初始化;最终产品 - 一个调整良好的PID控制器 - 有一种形式,从业者可以充分推理和部署。
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在不完整的数据集中对样本进行分类是机器学习从业人员的普遍目的,但并非平凡。在大多数现实世界数据集中发现缺失的数据,这些缺失值通常是使用已建立的方法估算的,然后进行分类现在完成,估算的样本。然后,机器学习研究人员的重点是优化下游分类性能。在这项研究中,我们强调必须考虑插补的质量。我们展示了如何评估质量的常用措施有缺陷,并提出了一类新的差异评分,这些分数着重于该方法重新创建数据的整体分布的程度。总而言之,我们强调了使用不良数据训练的分类器模型的可解释性损害。
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In this paper, we propose a novel technique, namely INVALIDATOR, to automatically assess the correctness of APR-generated patches via semantic and syntactic reasoning. INVALIDATOR reasons about program semantic via program invariants while it also captures program syntax via language semantic learned from large code corpus using the pre-trained language model. Given a buggy program and the developer-patched program, INVALIDATOR infers likely invariants on both programs. Then, INVALIDATOR determines that a APR-generated patch overfits if: (1) it violates correct specifications or (2) maintains errors behaviors of the original buggy program. In case our approach fails to determine an overfitting patch based on invariants, INVALIDATOR utilizes a trained model from labeled patches to assess patch correctness based on program syntax. The benefit of INVALIDATOR is three-fold. First, INVALIDATOR is able to leverage both semantic and syntactic reasoning to enhance its discriminant capability. Second, INVALIDATOR does not require new test cases to be generated but instead only relies on the current test suite and uses invariant inference to generalize the behaviors of a program. Third, INVALIDATOR is fully automated. We have conducted our experiments on a dataset of 885 patches generated on real-world programs in Defects4J. Experiment results show that INVALIDATOR correctly classified 79% overfitting patches, accounting for 23% more overfitting patches being detected by the best baseline. INVALIDATOR also substantially outperforms the best baselines by 14% and 19% in terms of Accuracy and F-Measure, respectively.
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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.
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The latent space of autoencoders has been improved for clustering image data by jointly learning a t-distributed embedding with a clustering algorithm inspired by the neighborhood embedding concept proposed for data visualization. However, multivariate tabular data pose different challenges in representation learning than image data, where traditional machine learning is often superior to deep tabular data learning. In this paper, we address the challenges of learning tabular data in contrast to image data and present a novel Gaussian Cluster Embedding in Autoencoder Latent Space (G-CEALS) algorithm by replacing t-distributions with multivariate Gaussian clusters. Unlike current methods, the proposed approach independently defines the Gaussian embedding and the target cluster distribution to accommodate any clustering algorithm in representation learning. A trained G-CEALS model extracts a quality embedding for unseen test data. Based on the embedding clustering accuracy, the average rank of the proposed G-CEALS method is 1.4 (0.7), which is superior to all eight baseline clustering and cluster embedding methods on seven tabular data sets. This paper shows one of the first algorithms to jointly learn embedding and clustering to improve multivariate tabular data representation in downstream clustering.
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An unbiased scene graph generation (SGG) algorithm referred to as Skew Class-balanced Re-weighting (SCR) is proposed for considering the unbiased predicate prediction caused by the long-tailed distribution. The prior works focus mainly on alleviating the deteriorating performances of the minority predicate predictions, showing drastic dropping recall scores, i.e., losing the majority predicate performances. It has not yet correctly analyzed the trade-off between majority and minority predicate performances in the limited SGG datasets. In this paper, to alleviate the issue, the Skew Class-balanced Re-weighting (SCR) loss function is considered for the unbiased SGG models. Leveraged by the skewness of biased predicate predictions, the SCR estimates the target predicate weight coefficient and then re-weights more to the biased predicates for better trading-off between the majority predicates and the minority ones. Extensive experiments conducted on the standard Visual Genome dataset and Open Image V4 \& V6 show the performances and generality of the SCR with the traditional SGG models.
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In this paper we discuss the theory used in the design of an open source lightmorphic signatures analysis toolkit (LSAT). In addition to providing a core functionality, the software package enables specific optimizations with its modular and customizable design. To promote its usage and inspire future contributions, LSAT is publicly available. By using a self-supervised neural network and augmented machine learning algorithms, LSAT provides an easy-to-use interface with ample documentation. The experiments demonstrate that LSAT improves the otherwise tedious and error-prone tasks of translating lightmorphic associated data into usable spectrograms, enhanced with parameter tuning and performance analysis. With the provided mathematical functions, LSAT validates the nonlinearity encountered in the data conversion process while ensuring suitability of the forecasting algorithms.
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Most Graph Neural Networks follow the message-passing paradigm, assuming the observed structure depicts the ground-truth node relationships. However, this fundamental assumption cannot always be satisfied, as real-world graphs are always incomplete, noisy, or redundant. How to reveal the inherent graph structure in a unified way remains under-explored. We proposed PRI-GSL, a Graph Structure Learning framework guided by the Principle of Relevant Information, providing a simple and unified framework for identifying the self-organization and revealing the hidden structure. PRI-GSL learns a structure that contains the most relevant yet least redundant information quantified by von Neumann entropy and Quantum Jensen-Shannon divergence. PRI-GSL incorporates the evolution of quantum continuous walk with graph wavelets to encode node structural roles, showing in which way the nodes interplay and self-organize with the graph structure. Extensive experiments demonstrate the superior effectiveness and robustness of PRI-GSL.
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