A framework for creating and updating digital twins for dynamical systems from a library of physics-based functions is proposed. The sparse Bayesian machine learning is used to update and derive an interpretable expression for the digital twin. Two approaches for updating the digital twin are proposed. The first approach makes use of both the input and output information from a dynamical system, whereas the second approach utilizes output-only observations to update the digital twin. Both methods use a library of candidate functions representing certain physics to infer new perturbation terms in the existing digital twin model. In both cases, the resulting expressions of updated digital twins are identical, and in addition, the epistemic uncertainties are quantified. In the first approach, the regression problem is derived from a state-space model, whereas in the latter case, the output-only information is treated as a stochastic process. The concepts of It\^o calculus and Kramers-Moyal expansion are being utilized to derive the regression equation. The performance of the proposed approaches is demonstrated using highly nonlinear dynamical systems such as the crack-degradation problem. Numerical results demonstrated in this paper almost exactly identify the correct perturbation terms along with their associated parameters in the dynamical system. The probabilistic nature of the proposed approach also helps in quantifying the uncertainties associated with updated models. The proposed approaches provide an exact and explainable description of the perturbations in digital twin models, which can be directly used for better cyber-physical integration, long-term future predictions, degradation monitoring, and model-agnostic control.
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We propose a novel model agnostic data-driven reliability analysis framework for time-dependent reliability analysis. The proposed approach -- referred to as MAntRA -- combines interpretable machine learning, Bayesian statistics, and identifying stochastic dynamic equation to evaluate reliability of stochastically-excited dynamical systems for which the governing physics is \textit{apriori} unknown. A two-stage approach is adopted: in the first stage, an efficient variational Bayesian equation discovery algorithm is developed to determine the governing physics of an underlying stochastic differential equation (SDE) from measured output data. The developed algorithm is efficient and accounts for epistemic uncertainty due to limited and noisy data, and aleatoric uncertainty because of environmental effect and external excitation. In the second stage, the discovered SDE is solved using a stochastic integration scheme and the probability failure is computed. The efficacy of the proposed approach is illustrated on three numerical examples. The results obtained indicate the possible application of the proposed approach for reliability analysis of in-situ and heritage structures from on-site measurements.
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在科学技术的许多领域中,从数据中提取理事物理学是一个关键挑战。方程发现的现有技术取决于输入和状态测量。但是,实际上,我们只能访问输出测量。我们在这里提出了一个新的框架,用于从输出测量中学习动态系统的物理学;这本质上将物理发现问题从确定性转移到随机域。提出的方法将输入模拟为随机过程,并将随机演算,稀疏学习算法和贝叶斯统计的概念融合在一起。特别是,我们将稀疏性结合起来,促进尖峰和平板先验,贝叶斯法和欧拉·马鲁山(Euler Maruyama)计划,以从数据中识别统治物理。最终的模型高效,可以进行稀疏,嘈杂和不完整的输出测量。在涉及完整状态测量和部分状态测量的几个数值示例中说明了所提出方法的功效和鲁棒性。获得的结果表明,拟议方法仅从产出测量中识别物理学的潜力。
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操作员的学习框架由于其能够在两个无限尺寸功能空间之间学习非线性图和神经网络的利用能力,因此最近成为应用机器学习领域中最相关的领域之一。尽管这些框架在建模复杂现象方面具有极大的能力,但它们需要大量数据才能成功培训,这些数据通常是不可用或太昂贵的。但是,可以通过使用多忠诚度学习来缓解此问题,在这种学习中,通过使用大量廉价的低保真数据以及少量昂贵的高保真数据来训练模型。为此,我们开发了一个基于小波神经操作员的新框架,该框架能够从多保真数据集中学习。通过解决不同的问题,需要在两个忠诚度之间进行有效的相关性学习来证明开发模型的出色学习能力。此外,我们还评估了开发框架在不确定性定量中的应用。从这项工作中获得的结果说明了拟议框架的出色表现。
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Machine Translation (MT) system generally aims at automatic representation of source language into target language retaining the originality of context using various Natural Language Processing (NLP) techniques. Among various NLP methods, Statistical Machine Translation(SMT). SMT uses probabilistic and statistical techniques to analyze information and conversion. This paper canvasses about the development of bilingual SMT models for translating English to fifteen low-resource Indian Languages (ILs) and vice versa. At the outset, all 15 languages are briefed with a short description related to our experimental need. Further, a detailed analysis of Samanantar and OPUS dataset for model building, along with standard benchmark dataset (Flores-200) for fine-tuning and testing, is done as a part of our experiment. Different preprocessing approaches are proposed in this paper to handle the noise of the dataset. To create the system, MOSES open-source SMT toolkit is explored. Distance reordering is utilized with the aim to understand the rules of grammar and context-dependent adjustments through a phrase reordering categorization framework. In our experiment, the quality of the translation is evaluated using standard metrics such as BLEU, METEOR, and RIBES
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机器翻译系统(MTS)是通过将文本或语音从一种语言转换为另一种语言的有效工具。在像印度这样的大型多语言环境中,对有效的翻译系统的需求变得显而易见,英语和一套印度语言(ILS)正式使用。与英语相反,由于语料库的不可用,IL仍然被视为低资源语言。为了解决不对称性质,多语言神经机器翻译(MNMT)系统会发展为在这个方向上的理想方法。在本文中,我们提出了一个MNMT系统,以解决与低资源语言翻译有关的问题。我们的模型包括两个MNMT系统,即用于英语印度(一对多),另一个用于指示英语(多一对多),其中包含15个语言对(30个翻译说明)的共享编码器码头。由于大多数IL对具有很少的平行语料库,因此不足以训练任何机器翻译模型。我们探索各种增强策略,以通过建议的模型提高整体翻译质量。最先进的变压器体系结构用于实现所提出的模型。大量数据的试验揭示了其优越性比常规模型的优势。此外,本文解决了语言关系的使用(在方言,脚本等方面),尤其是关于同一家族的高资源语言在提高低资源语言表现方面的作用。此外,实验结果还表明了ILS的倒退和域适应性的优势,以提高源和目标语言的翻译质量。使用所有这些关键方法,我们提出的模型在评估指标方面比基线模型更有效,即一组ILS的BLEU(双语评估研究)得分。
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产品的属性值是任何电子商务平台中必不可少的组件。属性值提取(AVE)涉及从其标题或描述中提取产品的属性及其值。在本文中,我们建议使用生成框架解决AVE任务。我们通过将AVE任务作为生成问题制定,即基于单词序列和基于位置的生成范式,即基于单词序列和位置序列。我们在两个数据集上进行实验,在该数据集中生成方法获得了新的最新结果。这表明我们可以将建议的框架用于AVE任务,而无需其他标记或特定于任务的模型设计。
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自动言论(POS)标记是许多自然语言处理(NLP)任务的预处理步骤,例如名称实体识别(NER),语音处理,信息提取,单词sense sisse disampigation和Machine Translation。它已经在英语和欧洲语言方面取得了令人鼓舞的结果,但是使用印度语言,尤其是在Odia语言中,由于缺乏支持工具,资源和语言形态丰富性,因此尚未得到很好的探索。不幸的是,我们无法为ODIA找到一个开源POS标记,并且仅尝试为ODIA语言开发POS标记器的尝试。这项研究工作的主要贡献是介绍有条件的随机场(CRF)和基于深度学习的方法(CNN和双向长期短期记忆)来开发ODIA的语音部分。我们使用了一个公开访问的语料库,并用印度标准局(BIS)标签设定了数据集。但是,全球的大多数语言都使用了带有通用依赖项(UD)标签集注释的数据集。因此,要保持统一性,odia数据集应使用相同的标签集。因此,我们已经构建了一个从BIS标签集到UD标签集的简单映射。我们对CRF模型进行了各种特征集输入,观察到构造特征集的影响。基于深度学习的模型包括BI-LSTM网络,CNN网络,CRF层,角色序列信息和预训练的单词向量。通过使用卷积神经网络(CNN)和BI-LSTM网络提取角色序列信息。实施了神经序列标记模型的六种不同组合,并研究了其性能指标。已经观察到具有字符序列特征和预训练的单词矢量的BI-LSTM模型取得了显着的最新结果。
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在这项工作中,提出了基于实时手势识别系统的实时手势识别系统界面(HCI)。该系统由六个阶段组成:(1)手势分割,(3)使用转移学习方法使用六个预训练的CNN模型,(4)构建交互式的人机界面,(( 5)开发手势控制的虚拟鼠标,(6)使用卡尔曼过滤器来估计手部位置,因为指针的平滑度得到了改善。六个预训练的卷积神经网络(CNN)模型(VGG16,VGG19,RESNET50,RESNET101,INCEPTION-V1和MOBILENET-V1)已用于对手势图像进行分类。三个多级数据集(两个公开和一个自定义)已用于评估模型性能。考虑到模型的性能,已经观察到,与其他五个预训练的模型相比,Inception-V1在准确性,精度,召回和F-SCORE值方面表现出了更好的分类性能。手势识别系统已扩展并用于控制多媒体应用程序(例如VLC播放器,音频播放器,文件管理,播放2D Super-Mario-Bros游戏等),并在实时场景中具有不同的自定义手势命令。该系统的平均速度已达到35 fps(每秒帧),满足实时场景的要求。
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