Process monitoring and control are essential in modern industries for ensuring high quality standards and optimizing production performance. These technologies have a long history of application in production and have had numerous positive impacts, but also hold great potential when integrated with Industry 4.0 and advanced machine learning, particularly deep learning, solutions. However, in order to implement these solutions in production and enable widespread adoption, the scalability and transferability of deep learning methods have become a focus of research. While transfer learning has proven successful in many cases, particularly with computer vision and homogenous data inputs, it can be challenging to apply to heterogeneous data. Motivated by the need to transfer and standardize established processes to different, non-identical environments and by the challenge of adapting to heterogeneous data representations, this work introduces the Domain Adaptation Neural Network with Cyclic Supervision (DBACS) approach. DBACS addresses the issue of model generalization through domain adaptation, specifically for heterogeneous data, and enables the transfer and scalability of deep learning-based statistical control methods in a general manner. Additionally, the cyclic interactions between the different parts of the model enable DBACS to not only adapt to the domains, but also match them. To the best of our knowledge, DBACS is the first deep learning approach to combine adaptation and matching for heterogeneous data settings. For comparison, this work also includes subspace alignment and a multi-view learning that deals with heterogeneous representations by mapping data into correlated latent feature spaces. Finally, DBACS with its ability to adapt and match, is applied to a virtual metrology use case for an etching process run on different machine types in semiconductor manufacturing.

虽然在许多域内生成并提供了大量的未标记数据，但对视觉数据的自动理解的需求高于以往任何时候。大多数现有机器学习模型通常依赖于大量标记的训练数据来实现高性能。不幸的是，在现实世界的应用中，不能满足这种要求。标签的数量有限，手动注释数据昂贵且耗时。通常需要将知识从现有标记域传输到新域。但是，模型性能因域之间的差异（域移位或数据集偏差）而劣化。为了克服注释的负担，域适应（DA）旨在在将知识从一个域转移到另一个类似但不同的域中时减轻域移位问题。无监督的DA（UDA）处理标记的源域和未标记的目标域。 UDA的主要目标是减少标记的源数据和未标记的目标数据之间的域差异，并在培训期间在两个域中学习域不变的表示。在本文中，我们首先定义UDA问题。其次，我们从传统方法和基于深度学习的方法中概述了不同类别的UDA的最先进的方法。最后，我们收集常用的基准数据集和UDA最先进方法的报告结果对视觉识别问题。

Transfer learning aims at improving the performance of target learners on target domains by transferring the knowledge contained in different but related source domains. In this way, the dependence on a large number of target domain data can be reduced for constructing target learners. Due to the wide application prospects, transfer learning has become a popular and promising area in machine learning. Although there are already some valuable and impressive surveys on transfer learning, these surveys introduce approaches in a relatively isolated way and lack the recent advances in transfer learning. Due to the rapid expansion of the transfer learning area, it is both necessary and challenging to comprehensively review the relevant studies. This survey attempts to connect and systematize the existing transfer learning researches, as well as to summarize and interpret the mechanisms and the strategies of transfer learning in a comprehensive way, which may help readers have a better understanding of the current research status and ideas. Unlike previous surveys, this survey paper reviews more than forty representative transfer learning approaches, especially homogeneous transfer learning approaches, from the perspectives of data and model. The applications of transfer learning are also briefly introduced. In order to show the performance of different transfer learning models, over twenty representative transfer learning models are used for experiments. The models are performed on three different datasets, i.e., Amazon Reviews, Reuters-21578, and Office-31. And the experimental results demonstrate the importance of selecting appropriate transfer learning models for different applications in practice.

Deep learning has produced state-of-the-art results for a variety of tasks. While such approaches for supervised learning have performed well, they assume that training and testing data are drawn from the same distribution, which may not always be the case. As a complement to this challenge, single-source unsupervised domain adaptation can handle situations where a network is trained on labeled data from a source domain and unlabeled data from a related but different target domain with the goal of performing well at test-time on the target domain. Many single-source and typically homogeneous unsupervised deep domain adaptation approaches have thus been developed, combining the powerful, hierarchical representations from deep learning with domain adaptation to reduce reliance on potentially-costly target data labels. This survey will compare these approaches by examining alternative methods, the unique and common elements, results, and theoretical insights. We follow this with a look at application areas and open research directions.

最近的智能故障诊断（IFD）的进展大大依赖于深度代表学习和大量标记数据。然而，机器通常以各种工作条件操作，或者目标任务具有不同的分布，其中包含用于训练的收集数据（域移位问题）。此外，目标域中的新收集的测试数据通常是未标记的，导致基于无监督的深度转移学习（基于UDTL为基础的）IFD问题。虽然它已经实现了巨大的发展，但标准和开放的源代码框架以及基于UDTL的IFD的比较研究尚未建立。在本文中，我们根据不同的任务，构建新的分类系统并对基于UDTL的IFD进行全面审查。对一些典型方法和数据集的比较分析显示了基于UDTL的IFD中的一些开放和基本问题，这很少研究，包括特征，骨干，负转移，物理前导等的可转移性，强调UDTL的重要性和再现性 - 基于IFD，整个测试框架将发布给研究界以促进未来的研究。总之，发布的框架和比较研究可以作为扩展界面和基本结果，以便对基于UDTL的IFD进行新的研究。代码框架可用于\ url {https:/github.com/zhaozhibin/udtl}。

大量的数据和创新算法使数据驱动的建模成为现代行业的流行技术。在各种数据驱动方法中，潜在变量模型（LVM）及其对应物占主要份额，并在许多工业建模领域中起着至关重要的作用。 LVM通常可以分为基于统计学习的经典LVM和基于神经网络的深层LVM（DLVM）。我们首先讨论经典LVM的定义，理论和应用，该定义和应用既是综合教程，又是对经典LVM的简短申请调查。然后，我们对当前主流DLVM进行了彻底的介绍，重点是其理论和模型体系结构，此后不久就提供了有关DLVM的工业应用的详细调查。上述两种类型的LVM具有明显的优势和缺点。具体而言，经典的LVM具有简洁的原理和良好的解释性，但是它们的模型能力无法解决复杂的任务。基于神经网络的DLVM具有足够的模型能力，可以在复杂的场景中实现令人满意的性能，但它以模型的解释性和效率为例。旨在结合美德并减轻这两种类型的LVM的缺点，并探索非神经网络的举止以建立深层模型，我们提出了一个新颖的概念，称为“轻量级Deep LVM（LDLVM）”。在提出了这个新想法之后，该文章首先阐述了LDLVM的动机和内涵，然后提供了两个新颖的LDLVM，并详尽地描述了其原理，建筑和优点。最后，讨论了前景和机会，包括重要的开放问题和可能的研究方向。

无监督的域适应（UDA）显示出近年来工作条件下的轴承故障诊断的显着结果。但是，大多数UDA方法都不考虑数据的几何结构。此外，通常应用全局域适应技术，这忽略了子域之间的关系。本文通过呈现新的深亚域适应图卷积神经网络（DSAGCN）来解决提到的挑战，具有两个关键特性：首先，采用图形卷积神经网络（GCNN）来模拟数据结构。二，对抗域适应和局部最大平均差异（LMMD）方法同时应用，以对准子域的分布并降低相关子域和全局域之间的结构差异。 CWRU和Paderborn轴承数据集用于验证DSAGCN方法的比较模型之间的效率和优越性。实验结果表明，将结构化子域与域适应方法对准，以获得无监督故障诊断的准确数据驱动模型。

当机器学习模型将其应用于与最初训练的数据相似但不同的域中的数据时，它的性能会降低。为了减轻此域移位问题，域Adaptation（DA）技术搜索了最佳转换，该转换将（当前）输入数据从源域转换为目标域，以学习域名不变的表示，以减少域差异。本文根据两个步骤提出了一个新颖的监督DA。首先，我们从几个样本中搜索从源到目标域的最佳类依赖性转换。我们考虑了最佳的运输方法，例如地球搬运工的距离，凹痕传输和相关对准。其次，我们使用嵌入相似技术在推理时选择相应的转换。我们使用相关指标和高阶矩匹配技术。我们对具有域移动的时间序列数据集进行了广泛的评估，包括模拟和各种在线手写数据集，以演示性能。

A systematic review on machine-learning strategies for improving generalizability (cross-subjects and cross-sessions) electroencephalography (EEG) based in emotion classification was realized. In this context, the non-stationarity of EEG signals is a critical issue and can lead to the Dataset Shift problem. Several architectures and methods have been proposed to address this issue, mainly based on transfer learning methods. 418 papers were retrieved from the Scopus, IEEE Xplore and PubMed databases through a search query focusing on modern machine learning techniques for generalization in EEG-based emotion assessment. Among these papers, 75 were found eligible based on their relevance to the problem. Studies lacking a specific cross-subject and cross-session validation strategy and making use of other biosignals as support were excluded. On the basis of the selected papers' analysis, a taxonomy of the studies employing Machine Learning (ML) methods was proposed, together with a brief discussion on the different ML approaches involved. The studies with the best results in terms of average classification accuracy were identified, supporting that transfer learning methods seem to perform better than other approaches. A discussion is proposed on the impact of (i) the emotion theoretical models and (ii) psychological screening of the experimental sample on the classifier performances.

由于培训和测试数据分布之间的域移动，新的操作条件可能会导致故障诊断模型的大量性能下降。尽管已经提出了几种域的适应方法来克服此类域移位，但如果两个域中表示的故障类别不相同，则其应用是有限的。为了在两个不同的域之间启用训练有素的模型的更好可传递性，尤其是在两个域之间仅共享健康数据类别的设置中，我们提出了一个新的框架，以基于生成不同的故障签名的部分和开放式域适应一个瓦斯林甘。提出的框架的主要贡献是具有两个主要不同特征的受控合成断层数据生成。首先，所提出的方法使目标域中仅能访问目标域中的健康样品和源域中的样本错误，从而在目标域中生成未观察到的故障类型。其次，可以将故障产生控制以精确生成不同的故障类型和故障严重程度。所提出的方法特别适合于极端域的适应设置，这些设置在复杂和安全关键系统的背景下特别相关，其中两个域之间仅共享一个类。我们在两个轴承断层诊断案例研究上评估了部分和开放式域适应任务的拟议框架。我们在不同标签空间设置中进行的实验展示了提出的框架的多功能性。与给定较大域间隙的其他方法相比，提出的方法提供了优越的结果。

We introduce a new representation learning approach for domain adaptation, in which data at training and test time come from similar but different distributions. Our approach is directly inspired by the theory on domain adaptation suggesting that, for effective domain transfer to be achieved, predictions must be made based on features that cannot discriminate between the training (source) and test (target) domains.The approach implements this idea in the context of neural network architectures that are trained on labeled data from the source domain and unlabeled data from the target domain (no labeled target-domain data is necessary). As the training progresses, the approach promotes the emergence of features that are (i) discriminative for the main learning task on the source domain and (ii) indiscriminate with respect to the shift between the domains. We show that this adaptation behaviour can be achieved in almost any feed-forward model by augmenting it with few standard layers and a new gradient reversal layer. The resulting augmented architecture can be trained using standard backpropagation and stochastic gradient descent, and can thus be implemented with little effort using any of the deep learning packages.We demonstrate the success of our approach for two distinct classification problems (document sentiment analysis and image classification), where state-of-the-art domain adaptation performance on standard benchmarks is achieved. We also validate the approach for descriptor learning task in the context of person re-identification application.

Deep domain adaptation has emerged as a new learning technique to address the lack of massive amounts of labeled data. Compared to conventional methods, which learn shared feature subspaces or reuse important source instances with shallow representations, deep domain adaptation methods leverage deep networks to learn more transferable representations by embedding domain adaptation in the pipeline of deep learning. There have been comprehensive surveys for shallow domain adaptation, but few timely reviews the emerging deep learning based methods. In this paper, we provide a comprehensive survey of deep domain adaptation methods for computer vision applications with four major contributions. First, we present a taxonomy of different deep domain adaptation scenarios according to the properties of data that define how two domains are diverged. Second, we summarize deep domain adaptation approaches into several categories based on training loss, and analyze and compare briefly the state-of-the-art methods under these categories. Third, we overview the computer vision applications that go beyond image classification, such as face recognition, semantic segmentation and object detection. Fourth, some potential deficiencies of current methods and several future directions are highlighted.

深度学习已成为解决不同领域中现实世界中问题的首选方法，部分原因是它能够从数据中学习并在广泛的应用程序上实现令人印象深刻的性能。但是，它的成功通常取决于两个假设：（i）精确模型拟合需要大量标记的数据集，并且（ii）培训和测试数据是独立的且分布相同的。因此，不能保证它在看不见的目标域上的性能，尤其是在适应阶段遇到分布数据的数据时。目标域中数据的性能下降是部署深层神经网络的关键问题，这些网络已成功地在源域中的数据训练。通过利用标记的源域数据和未标记的目标域数据来执行目标域中的各种任务，提出了无监督的域适应（UDA）来对抗这一点。 UDA在自然图像处理，视频分析，自然语言处理，时间序列数据分析，医学图像分析等方面取得了令人鼓舞的结果。在本综述中，作为一个快速发展的主题，我们对其方法和应用程序进行了系统的比较。此外，还讨论了UDA与其紧密相关的任务的联系，例如域的概括和分布外检测。此外，突出显示了当前方法和可能有希望的方向的缺陷。

无监督域适应（UDA）已成功解决了可视应用程序的域移位问题。然而，由于以下原因，这些方法可能对时间序列数据的性能有限。首先，它们主要依赖于用于源预制的大规模数据集（即，ImageNet），这不适用于时间序列数据。其次，它们在域对齐步骤期间忽略源极限和目标域的特征空间上的时间维度。最后，最先前的UDA方法中的大多数只能对齐全局特征而不考虑目标域的细粒度分布。为了解决这些限制，我们提出了一个自我监督的自回归域适应（Slarda）框架。特别是，我们首先设计一个自我监督的学习模块，它利用预测作为辅助任务以提高源特征的可转换性。其次，我们提出了一种新的自回归域自适应技术，其包括在域对齐期间源和目标特征的时间依赖性。最后，我们开发了一个集合教师模型，通过自信的伪标记方法对准目标域中的类明智分发。已经在三个现实世界时间序列应用中进行了广泛的实验，具有30个跨域方案。结果表明，我们所提出的杆状方法明显优于时序序列域适应的最先进的方法。

域适应性是现代机器学习中的一种流行范式，旨在解决培训或验证数据集之间具有用于学习和测试分类器（源域）和潜在的大型未标记数据集的培训或验证数据集之间的分歧问题，其中利用了模型（目标域）（目标域）（目标域） 。任务是找到源数据集的源和目标数据集的这种常见表示，其中源数据集提供了培训的信息，因此可以最大程度地减少来源和目标之间的差异。目前，最流行的领域适应性解决方案是基于训练神经网络，这些神经网络结合了分类和对抗性学习模块，这些模块是饥饿的，通常很难训练。我们提出了一种称为域适应性主成分分析（DAPCA）的方法，该方法发现线性减少的数据表示有助于解决域适应任务。 DAPCA基于数据点对之间引入正权重，并概括了主成分分析的监督扩展。 DAPCA代表一种迭代算法，因此在每次迭代中都解决了一个简单的二次优化问题。保证算法的收敛性，并且在实践中的迭代次数很少。我们验证了先前提出的用于解决域适应任务的基准的建议算法，还显示了在生物医学应用中对单细胞法数据集进行分析中使用DAPCA的好处。总体而言，考虑到源域和目标域之间可能的差异，DAPCA可以作为许多机器学习应用程序中有用的预处理步骤。

预后和健康管理（PHM）是一个新兴领域，由于其带来的好处和效率，它引起了制造业的广泛关注。剩余的使用寿命（RUR）预测是任何PHM系统的核心。最新数据驱动的研究要求大量标记的培训数据可以在有监督的学习范式下培训表现模型之前。在这里，转移学习（TL）和域适应（DA）方法介入并使我们有可能将监督模型概括为具有不同数据分布的其他没有标记数据的其他域。在本文中，我们提出了一种基于编码的模型（变压器），该模型（变压器）具有诱导的瓶颈，使用最大平均差异（MMD）的潜在对齐，并提出了歧管学习，以解决无监督的同质域的问题适应Rul预测。 \ textit {lama-net}使用NASA使用C-Mapss Turbofan引擎数据集验证，并将其与DA的其他最新技术进行了比较。结果表明，所提出的方法提供了一种有希望的方法来在RUL预测中进行域适应。一旦纸张退出审查，将提供代码。

语义分割在广泛的计算机视觉应用中起着基本作用，提供了全球对图像​​的理解的关键信息。然而，最先进的模型依赖于大量的注释样本，其比在诸如图像分类的任务中获得更昂贵的昂贵的样本。由于未标记的数据替代地获得更便宜，因此无监督的域适应达到了语义分割社区的广泛成功并不令人惊讶。本调查致力于总结这一令人难以置信的快速增长的领域的五年，这包含了语义细分本身的重要性，以及将分段模型适应新环境的关键需求。我们提出了最重要的语义分割方法;我们对语义分割的域适应技术提供了全面的调查;我们揭示了多域学习，域泛化，测试时间适应或无源域适应等较新的趋势;我们通过描述在语义细分研究中最广泛使用的数据集和基准测试来结束本调查。我们希望本调查将在学术界和工业中提供具有全面参考指导的研究人员，并有助于他们培养现场的新研究方向。

机器学习系统通常假设训练和测试分布是相同的。为此，关键要求是开发可以概括到未经看不见的分布的模型。领域泛化（DG），即分销概括，近年来引起了越来越令人利益。域概括处理了一个具有挑战性的设置，其中给出了一个或几个不同但相关域，并且目标是学习可以概括到看不见的测试域的模型。多年来，域概括地区已经取得了巨大进展。本文提出了对该地区最近进步的首次审查。首先，我们提供了域泛化的正式定义，并讨论了几个相关领域。然后，我们彻底审查了与域泛化相关的理论，并仔细分析了泛化背后的理论。我们将最近的算法分为三个类：数据操作，表示学习和学习策略，并为每个类别详细介绍几种流行的算法。第三，我们介绍常用的数据集，应用程序和我们的开放源代码库进行公平评估。最后，我们总结了现有文学，并为未来提供了一些潜在的研究主题。

Domain adaptation aims at generalizing a high-performance learner on a target domain via utilizing the knowledge distilled from a source domain which has a different but related data distribution. One solution to domain adaptation is to learn domain invariant feature representations while the learned representations should also be discriminative in prediction. To learn such representations, domain adaptation frameworks usually include a domain invariant representation learning approach to measure and reduce the domain discrepancy, as well as a discriminator for classification. Inspired by Wasserstein GAN, in this paper we propose a novel approach to learn domain invariant feature representations, namely Wasserstein Distance Guided Representation Learning (WD-GRL). WDGRL utilizes a neural network, denoted by the domain critic, to estimate empirical Wasserstein distance between the source and target samples and optimizes the feature extractor network to minimize the estimated Wasserstein distance in an adversarial manner. The theoretical advantages of Wasserstein distance for domain adaptation lie in its gradient property and promising generalization bound. Empirical studies on common sentiment and image classification adaptation datasets demonstrate that our proposed WDGRL outperforms the state-of-the-art domain invariant representation learning approaches.

Top-performing deep architectures are trained on massive amounts of labeled data. In the absence of labeled data for a certain task, domain adaptation often provides an attractive option given that labeled data of similar nature but from a different domain (e.g. synthetic images) are available. Here, we propose a new approach to domain adaptation in deep architectures that can be trained on large amount of labeled data from the source domain and large amount of unlabeled data from the target domain (no labeled targetdomain data is necessary).As the training progresses, the approach promotes the emergence of "deep" features that are (i) discriminative for the main learning task on the source domain and (ii) invariant with respect to the shift between the domains. We show that this adaptation behaviour can be achieved in almost any feed-forward model by augmenting it with few standard layers and a simple new gradient reversal layer. The resulting augmented architecture can be trained using standard backpropagation.Overall, the approach can be implemented with little effort using any of the deep-learning packages. The method performs very well in a series of image classification experiments, achieving adaptation effect in the presence of big domain shifts and outperforming previous state-ofthe-art on Office datasets.