A deep learning strategy is developed for fast and accurate gas property measurements using flame emission spectroscopy (FES). Particularly, the short-gated fast FES is essential to resolve fast-evolving combustion behaviors. However, as the exposure time for capturing the flame emission spectrum gets shorter, the signal-to-noise ratio (SNR) decreases, and characteristic spectral features indicating the gas properties become relatively weaker. Then, the property estimation based on the short-gated spectrum is difficult and inaccurate. Denoising convolutional neural networks (CNN) can enhance the SNR of the short-gated spectrum. A new CNN architecture including a reversible down- and up-sampling (DU) operator and a loss function based on proper orthogonal decomposition (POD) coefficients is proposed. For training and testing the CNN, flame chemiluminescence spectra were captured from a stable methane-air flat flame using a portable spectrometer (spectral range: 250 - 850 nm, resolution: 0.5 nm) with varied equivalence ratio (0.8 - 1.2), pressure (1 - 10 bar), and exposure time (0.05, 0.2, 0.4, and 2 s). The long exposure (2 s) spectra were used as the ground truth when training the denoising CNN. A kriging model with POD is trained by the long-gated spectra for calibration, and then the prediction of the gas properties taking the denoised short-gated spectrum as the input: The property prediction errors of pressure and equivalence ratio were remarkably lowered in spite of the low SNR attendant with reduced exposure.
translated by 谷歌翻译
气候,化学或天体物理学中的数值模拟在计算上对于高分辨率下的不确定性定量或参数探索而言太昂贵。减少或替代模型的多个数量级更快,但是传统的替代物是僵化或不准确和纯机器学习(ML)基于基于数据的替代物。我们提出了一个混合,灵活的替代模型,该模型利用已知的物理学来模拟大规模动力学,并将学习到难以模拟的项,该术语称为参数化或闭合,并捕获了细界面对大型动力学的影响。利用神经操作员,我们是第一个学习独立于网格的,非本地和灵活的参数化的人。我们的\ textit {多尺度神经操作员}是由多尺度建模的丰富文献进行的,具有准线性运行时复杂性,比最先进的参数化更准确或更灵活,并且在混乱方程的多尺度lorenz96上证明。
translated by 谷歌翻译
全球变暖导致气候极端频率和强度的增加,导致生活巨大损失。准确的远程气候预测允许更多时间进行准备和灾害风险管理,以获得此类极端事件。虽然机器学习方法已经表明了远程气候预测结果,但相关的模型不确定性可能会降低其可靠性。为了解决这个问题,我们提出了一种后期的融合方法,系统地将预测从多种模型中组合以减少融合结果的预期误差。我们还提出了一种具有新型Denormalization层的网络架构,以获得数据标准化的好处,而无需实际归一化数据。远程2M温度预测的实验结果表明,该框架优于30年气候法线,通过增加模型数量可以提高准确性。
translated by 谷歌翻译
联邦学习监督任务的深层学习模型,例如,图像分类和分割,已找到许多应用程序:例如,在人类的循环任务中,如电影后期生产,可以以高效且有效的方式分享人类艺术家的域专业知识。在许多此类应用程序中,我们需要在培训过程中共享由于知识产权或隐私问题而在培训过程中共享时保护培训数据。最近的作品已经证明,当其架构已知时,可以从梯度重建来自图像分类模型的梯度的训练数据。但是,对这种攻击的疗效和失败仍然存在不完整的理论理解。在本文中,我们分析了梯度的训练数据泄漏来源。我们制定培训数据重建的问题,因为为每层迭代地解决优化问题。层面的物理函数主要由来自电流层的权重和梯度与后续层的重建的输出定义,但是它还可能涉及从前面的层的“拉回”约束。当我们通过每层从网络的输出来解决问题时,可以重建训练数据。基于此配方,我们能够将培训数据的潜在泄漏归因于深度网络到其架构。我们还提出了一个指标来测量对基于梯度的攻击对训练数据的深度学习模型的安全水平。
translated by 谷歌翻译
在过去的几年中,深层神经网络方法的反向成像问题产生了令人印象深刻的结果。在本文中,我们考虑在跨问题方法中使用生成模型。所考虑的正规派对图像进行了惩罚,这些图像远非生成模型的范围,该模型学会了产生类似于训练数据集的图像。我们命名这个家庭\ textit {生成正规派}。生成常规人的成功取决于生成模型的质量,因此我们提出了一组所需的标准来评估生成模型并指导未来的研究。在我们的数值实验中,我们根据我们所需的标准评估了三种常见的生成模型,自动编码器,变异自动编码器和生成对抗网络。我们还测试了三个不同的生成正规疗法仪,关于脱毛,反卷积和断层扫描的逆问题。我们表明,逆问题的限制解决方案完全位于生成模型的范围内可以给出良好的结果,但是允许与发电机范围的小偏差产生更一致的结果。
translated by 谷歌翻译
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.
translated by 谷歌翻译
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.
translated by 谷歌翻译
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.
translated by 谷歌翻译
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.
translated by 谷歌翻译
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.
translated by 谷歌翻译