我们提出了一种新的方法,用于训练神经网络进行图像分类,以动态减少输入数据,以降低训练神经网络模型的成本。随着深度学习任务变得越来越流行,它们的计算复杂性会增加,从而导致更复杂的算法和模型,这些算法和模型具有更长的时间,并且需要更多的输入数据。结果是按时,硬件和环境资源的成本更高。通过使用数据降低技术,我们减少了执行的工作量以及AI技术的环境影响,并且通过动态数据降低,我们表明可以在将运行时保持高达50%的同时保持准确性,并按比例减少碳排放。
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In this study, we systematically investigate the impact of class imbalance on classification performance of convolutional neural networks (CNNs) and compare frequently used methods to address the issue. Class imbalance is a common problem that has been comprehensively studied in classical machine learning, yet very limited systematic research is available in the context of deep learning. In our study, we use three benchmark datasets of increasing complexity, MNIST, CIFAR-10 and ImageNet, to investigate the effects of imbalance on classification and perform an extensive comparison of several methods to address the issue: oversampling, undersampling, two-phase training, and thresholding that compensates for prior class probabilities. Our main evaluation metric is area under the receiver operating characteristic curve (ROC AUC) adjusted to multi-class tasks since overall accuracy metric is associated with notable difficulties in the context of imbalanced data. Based on results from our experiments we conclude that (i) the effect of class imbalance on classification performance is detrimental; (ii) the method of addressing class imbalance that emerged as dominant in almost all analyzed scenarios was oversampling; (iii) oversampling should be applied to the level that completely eliminates the imbalance, whereas the optimal undersampling ratio depends on the extent of imbalance; (iv) as opposed to some classical machine learning models, oversampling does not cause overfitting of CNNs; (v) thresholding should be applied to compensate for prior class probabilities when overall number of properly classified cases is of interest.
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近年来,计算机视觉社区中最受欢迎的技术之一就是深度学习技术。作为一种数据驱动的技术,深层模型需要大量准确标记的培训数据,这在许多现实世界中通常是无法访问的。数据空间解决方案是数据增强(DA),可以人为地从原始样本中生成新图像。图像增强策略可能因数据集而有所不同,因为不同的数据类型可能需要不同的增强以促进模型培训。但是,DA策略的设计主要由具有领域知识的人类专家决定,这被认为是高度主观和错误的。为了减轻此类问题,一个新颖的方向是使用自动数据增强(AUTODA)技术自动从给定数据集中学习图像增强策略。 Autoda模型的目的是找到可以最大化模型性能提高的最佳DA策略。这项调查从图像分类的角度讨论了Autoda技术出现的根本原因。我们确定标准自动赛车模型的三个关键组件:搜索空间,搜索算法和评估功能。根据他们的架构,我们提供了现有图像AUTODA方法的系统分类法。本文介绍了Autoda领域的主要作品,讨论了他们的利弊,并提出了一些潜在的方向以进行未来的改进。
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Although deep learning approaches have stood out in recent years due to their state-of-the-art results, they continue to suffer from catastrophic forgetting, a dramatic decrease in overall performance when training with new classes added incrementally. This is due to current neural network architectures requiring the entire dataset, consisting of all the samples from the old as well as the new classes, to update the model-a requirement that becomes easily unsustainable as the number of classes grows. We address this issue with our approach to learn deep neural networks incrementally, using new data and only a small exemplar set corresponding to samples from the old classes. This is based on a loss composed of a distillation measure to retain the knowledge acquired from the old classes, and a cross-entropy loss to learn the new classes. Our incremental training is achieved while keeping the entire framework end-to-end, i.e., learning the data representation and the classifier jointly, unlike recent methods with no such guarantees. We evaluate our method extensively on the CIFAR-100 and Im-ageNet (ILSVRC 2012) image classification datasets, and show state-of-the-art performance.
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Image classification with small datasets has been an active research area in the recent past. However, as research in this scope is still in its infancy, two key ingredients are missing for ensuring reliable and truthful progress: a systematic and extensive overview of the state of the art, and a common benchmark to allow for objective comparisons between published methods. This article addresses both issues. First, we systematically organize and connect past studies to consolidate a community that is currently fragmented and scattered. Second, we propose a common benchmark that allows for an objective comparison of approaches. It consists of five datasets spanning various domains (e.g., natural images, medical imagery, satellite data) and data types (RGB, grayscale, multispectral). We use this benchmark to re-evaluate the standard cross-entropy baseline and ten existing methods published between 2017 and 2021 at renowned venues. Surprisingly, we find that thorough hyper-parameter tuning on held-out validation data results in a highly competitive baseline and highlights a stunted growth of performance over the years. Indeed, only a single specialized method dating back to 2019 clearly wins our benchmark and outperforms the baseline classifier.
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随着深入学习更加标签的目标,越来越多的论文已经研究了深度模型的主动学习(AL)。然而,普遍存在的实验设置中存在许多问题,主要源于缺乏统一的实施和基准。当前文献中的问题包括有时对不同AL算法的性能的矛盾观察,意外排除重要的概括方法,如数据增强和SGD进行优化,缺乏对al的标签效率等评价方面的研究,并且很少或没有在Al优于随机采样(RS)的情况下的清晰度。在这项工作中,我们通过我们的新开源AL Toolkit Distil在图像分类的背景下统一重新实现了最先进的AL算法,我们仔细研究了这些问题作为有效评估的方面。在积极的方面,我们表明AL技术为2美元至4倍以上$ 4 \倍。与使用数据增强相比,与卢比相比,高效。令人惊讶的是,当包括数据增强时,在使用徽章,最先进的方法,在简单的不确定性采样中不再存在一致的增益。然后,我们仔细分析现有方法如何具有不同数量的冗余和每个类的示例。最后,我们为AL从业者提供了几次见解,以考虑在将来的工作中考虑,例如Al批量大小的效果,初始化的效果,在每一轮中再培训模型的重要性以及其他见解。
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When data is streaming from multiple sources, conventional training methods update model weights often assuming the same level of reliability for each source; that is: a model does not consider data quality of each source during training. In many applications, sources can have varied levels of noise or corruption that has negative effects on the learning of a robust deep learning model. A key issue is that the quality of data or labels for individual sources is often not available during training and could vary over time. Our solution to this problem is to consider the mistakes made while training on data originating from sources and utilise this to create a perceived data quality for each source. This paper demonstrates a straight-forward and novel technique that can be applied to any gradient descent optimiser: Update model weights as a function of the perceived reliability of data sources within a wider data set. The algorithm controls the plasticity of a given model to weight updates based on the history of losses from individual data sources. We show that applying this technique can significantly improve model performance when trained on a mixture of reliable and unreliable data sources, and maintain performance when models are trained on data sources that are all considered reliable. All code to reproduce this work's experiments and implement the algorithm in the reader's own models is made available.
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无线电星系的连续排放通常可以分为不同的形态学类,如FRI,Frii,弯曲或紧凑。在本文中,我们根据使用深度学习方法使用小规模数据集的深度学习方法来探讨基于形态的无线电星系分类的任务($ \ SIM 2000 $ Samples)。我们基于双网络应用了几次射击学习技术,并使用预先培训的DENSENET模型进行了先进技术的传输学习技术,如循环学习率和歧视性学习迅速训练模型。我们使用最佳表演模型实现了超过92 \%的分类准确性,其中最大的混乱来源是弯曲和周五型星系。我们的结果表明,专注于一个小但策划数据集随着使用最佳实践来训练神经网络可能会导致良好的结果。自动分类技术对于即将到来的下一代无线电望远镜的调查至关重要,这预计将在不久的将来检测数十万个新的无线电星系。
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With the development of a series of Galaxy sky surveys in recent years, the observations increased rapidly, which makes the research of machine learning methods for galaxy image recognition a hot topic. Available automatic galaxy image recognition researches are plagued by the large differences in similarity between categories, the imbalance of data between different classes, and the discrepancy between the discrete representation of Galaxy classes and the essentially gradual changes from one morphological class to the adjacent class (DDRGC). These limitations have motivated several astronomers and machine learning experts to design projects with improved galaxy image recognition capabilities. Therefore, this paper proposes a novel learning method, ``Hierarchical Imbalanced data learning with Weighted sampling and Label smoothing" (HIWL). The HIWL consists of three key techniques respectively dealing with the above-mentioned three problems: (1) Designed a hierarchical galaxy classification model based on an efficient backbone network; (2) Utilized a weighted sampling scheme to deal with the imbalance problem; (3) Adopted a label smoothing technique to alleviate the DDRGC problem. We applied this method to galaxy photometric images from the Galaxy Zoo-The Galaxy Challenge, exploring the recognition of completely round smooth, in between smooth, cigar-shaped, edge-on and spiral. The overall classification accuracy is 96.32\%, and some superiorities of the HIWL are shown based on recall, precision, and F1-Score in comparing with some related works. In addition, we also explored the visualization of the galaxy image features and model attention to understand the foundations of the proposed scheme.
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大多数杂草物种都会通过竞争高价值作物所需的营养而产生对农业生产力的不利影响。手动除草对于大型种植区不实用。已经开展了许多研究,为农业作物制定了自动杂草管理系统。在这个过程中,其中一个主要任务是识别图像中的杂草。但是,杂草的认可是一个具有挑战性的任务。它是因为杂草和作物植物的颜色,纹理和形状类似,可以通过成像条件,当记录图像时的成像条件,地理或天气条件进一步加剧。先进的机器学习技术可用于从图像中识别杂草。在本文中,我们调查了五个最先进的深神经网络,即VGG16,Reset-50,Inception-V3,Inception-Resnet-V2和MobileNetv2,并评估其杂草识别的性能。我们使用了多种实验设置和多个数据集合组合。特别是,我们通过组合几个较小的数据集,通过数据增强构成了一个大型DataSet,缓解了类别不平衡,并在基于深度神经网络的基准测试中使用此数据集。我们通过保留预先训练的权重来调查使用转移学习技术来利用作物和杂草数据集的图像提取特征和微调它们。我们发现VGG16比小规模数据集更好地执行,而ResET-50比其他大型数据集上的其他深网络更好地执行。
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随着大数据的爆炸性增加,培训机器学习(ML)模型成为计算密集型工作量,需要几天甚至几周。因此,重用已经训练的模型受到了受关注的,称为转移学习。转移学习避免通过将知识从源任务转移到目标任务来避免从头开始培训新模型。现有的传输学习方法主要专注于如何通过特定源模型提高目标任务的性能,并假设给出了源模型。虽然有许多源模型可用,但数据科学家难以手动选择目标任务的最佳源模型。因此,如何在模型数据库中有效地选择合适的源模型进行模型重用是一个有趣但未解决的问题。在本文中,我们提出了SMS,有效,高效,灵活的源模型选择框架。即使源数据集具有明显不同的数据标签,SMS也是有效的,并且灵活地支持具有任何类型的结构的源模型,并且有效地避免任何培训过程。对于每个源模型,SMS首先将目标数据集中的样本加速到软标签中,通过直接将该模型直接应用于目标数据集,然后使用高斯分布适合软标签的集群,最后测量源模型使用的显着能力高斯混合的公制。此外,我们提出了一种改进的SMS(I-SMS),其降低了源模型的输出数量。 I-SMS可以显着降低选择时间,同时保留SMS的选择性能。关于一系列实用模型重用工作负载的广泛实验证明了SMS的有效性和效率。
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为了确保全球粮食安全和利益相关者的总体利润,正确检测和分类植物疾病的重要性至关重要。在这方面,基于深度学习的图像分类的出现引入了大量解决方案。但是,这些解决方案在低端设备中的适用性需要快速,准确和计算廉价的系统。这项工作提出了一种基于轻巧的转移学习方法,用于从番茄叶中检测疾病。它利用一种有效的预处理方法来增强具有照明校正的叶片图像,以改善分类。我们的系统使用组合模型来提取功能,该模型由预审计的MobilenETV2体系结构和分类器网络组成,以进行有效的预测。传统的增强方法被运行时的增加取代,以避免数据泄漏并解决类不平衡问题。来自PlantVillage数据集的番茄叶图像的评估表明,所提出的体系结构可实现99.30%的精度,型号大小为9.60mb和4.87亿个浮点操作,使其成为低端设备中现实生活的合适选择。我们的代码和型号可在https://github.com/redwankarimsony/project-tomato中找到。
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对网络规模数据进行培训可能需要几个月的时间。但是,在已经学习或不可学习的冗余和嘈杂点上浪费了很多计算和时间。为了加速训练,我们引入了可减少的持有损失选择(Rho-loss),这是一种简单但原则上的技术,它大致选择了这些训练点,最大程度地减少了模型的概括损失。结果,Rho-loss减轻了现有数据选择方法的弱点:优化文献中的技术通常选择“硬损失”(例如,高损失),但是这种点通常是嘈杂的(不可学习)或更少的任务与任务相关。相反,课程学习优先考虑“简单”的积分,但是一旦学习,就不必对这些要点进行培训。相比之下,Rho-Loss选择了可以学习的点,值得学习的,尚未学习。与先前的艺术相比,Rho-loss火车的步骤要少得多,可以提高准确性,并加快对广泛的数据集,超参数和体系结构(MLP,CNNS和BERT)的培训。在大型Web绑带图像数据集服装1M上,与统一的数据改组相比,步骤少18倍,最终精度的速度少2%。
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神经网络的宽度很重要,因为增加了宽度,这必然会增加模型容量。但是,网络的性能不会随宽度而线性地提高,并且很快就会饱和。在这种情况下,我们认为,增加网络数量(合奏)的数量比纯粹增加宽度可以实现更好的准确性效率折衷。为了证明这一点,一个大型网络就其参数和正则化组件分为几个小网络。这些小型网络中的每一个都有原始参数的一小部分。然后,我们一起训练这些小型网络,使他们看到相同数据的各种观点,以增加它们的多样性。在此共同培训过程中,网络也可以相互学习。结果,小型网络可以比几乎没有或没有额外参数或拖船的大型网络获得更好的合奏性能,即实现更好的准确性效率折衷。通过并发运行,小型网络还可以比大型推理速度更快。以上所有内容都表明,网络的数量是模型缩放的新维度。我们通过广泛的实验在共同基准上使用8种不同的神经体系结构来验证我们的论点。该代码可在\ url {https://github.com/freeformrobotics/divide-and-co-training}中获得。
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Large-batch SGD is important for scaling training of deep neural networks. However, without fine-tuning hyperparameter schedules, the generalization of the model may be hampered. We propose to use batch augmentation: replicating instances of samples within the same batch with different data augmentations. Batch augmentation acts as a regularizer and an accelerator, increasing both generalization and performance scaling for a fixed budget of optimization steps. We analyze the effect of batch augmentation on gradient variance and show that it empirically improves convergence for a wide variety of networks and datasets. Our results show that batch augmentation reduces the number of necessary SGD updates to achieve the same accuracy as the state-of-the-art. Overall, this simple yet effective method enables faster training and better generalization by allowing more computational resources to be used concurrently. Large batch training of neural networksRecent approaches by [10], [8], [41] and others show that by adapting the optimization regime (i.e., hyperparameter schedule), large batch training can achieve equally good
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当在具有不同分布的数据集上不断学习时,神经网络往往会忘记以前学习的知识,这一现象被称为灾难性遗忘。数据集之间的分配更改会导致更多的遗忘。最近,基于参数 - 隔离的方法在克服遗忘时具有巨大的潜力。但是,当他们在培训过程中修复每个数据集的神经路径时,他们的概括不佳,并且在推断过程中需要数据集标签。此外,他们不支持向后的知识转移,因为它们优先于过去的数据。在本文中,我们提出了一种名为ADAPTCL的新的自适应学习方法,该方法完全重复使用并在学习的参数上生长,以克服灾难性的遗忘,并允许在不需要数据集标签的情况下进行积极的向后传输。我们提出的技术通过允许最佳的冷冻参数重复使用在相同的神经路径上生长。此外,它使用参数级数据驱动的修剪来为数据分配同等优先级。我们对MNIST变体,域和食物新鲜度检测数据集进行了广泛的实验,而无需数据集标签。结果表明,我们所提出的方法优于替代基线,可以最大程度地减少遗忘和实现积极的向后知识转移。
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Recent developments in in-situ monitoring and process control in Additive Manufacturing (AM), also known as 3D-printing, allows the collection of large amounts of emission data during the build process of the parts being manufactured. This data can be used as input into 3D and 2D representations of the 3D-printed parts. However the analysis and use, as well as the characterization of this data still remains a manual process. The aim of this paper is to propose an adaptive human-in-the-loop approach using Machine Learning techniques that automatically inspect and annotate the emissions data generated during the AM process. More specifically, this paper will look at two scenarios: firstly, using convolutional neural networks (CNNs) to automatically inspect and classify emission data collected by in-situ monitoring and secondly, applying Active Learning techniques to the developed classification model to construct a human-in-the-loop mechanism in order to accelerate the labeling process of the emission data. The CNN-based approach relies on transfer learning and fine-tuning, which makes the approach applicable to other industrial image patterns. The adaptive nature of the approach is enabled by uncertainty sampling strategy to automatic selection of samples to be presented to human experts for annotation.
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We build new test sets for the CIFAR-10 and ImageNet datasets. Both benchmarks have been the focus of intense research for almost a decade, raising the danger of overfitting to excessively re-used test sets. By closely following the original dataset creation processes, we test to what extent current classification models generalize to new data. We evaluate a broad range of models and find accuracy drops of 3% -15% on CIFAR-10 and 11% -14% on ImageNet. However, accuracy gains on the original test sets translate to larger gains on the new test sets. Our results suggest that the accuracy drops are not caused by adaptivity, but by the models' inability to generalize to slightly "harder" images than those found in the original test sets.
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在理论上和经验上,已经显示了深度神经网络的集合,以提高看不见的试验集上的泛化精度。然而,高训练成本阻碍了其效率,因为我们需要足够数量的基础模型,并且集合中的每一个都必须单独培训。提出了许多方法来解决这个问题,而且大多数基于预先训练的网络可以将其知识转移到下一个基础模型,然后加速培训过程的特征。然而,这些方法遭受严重的问题,即所有这些都会在没有选择的情况下传输知识,从而导致多样化。由于集合学习的效果更明显,如果合并成员是准确和多样化的,我们提出了一种命名为高效分集驱动的合奏(EDDE)的方法来解决集合的多样性和效率。为了加快培训过程,我们提出了一种新颖的知识转移方法,可以选择性地转移以前的通用知识。为了增强多样性,我们首先提出了一种新的多样性度量,然后使用它来定义多样性驱动的损耗功能以进行优化。最后,我们采用基于升级的框架来结合上述操作,这种方法还可以进一步提高分集。我们在计算机视觉(CV)和自然语言处理(NLP)任务中评估EDDE。与其他众所周知的集合方法相比,EDDE可以获得最高的合奏精度,培训成本最低,这意味着它在神经网络的集合中有效。
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Model bias triggered by long-tailed data has been widely studied. However, measure based on the number of samples cannot explicate three phenomena simultaneously: (1) Given enough data, the classification performance gain is marginal with additional samples. (2) Classification performance decays precipitously as the number of training samples decreases when there is insufficient data. (3) Model trained on sample-balanced datasets still has different biases for different classes. In this work, we define and quantify the semantic scale of classes, which is used to measure the feature diversity of classes. It is exciting to find experimentally that there is a marginal effect of semantic scale, which perfectly describes the first two phenomena. Further, the quantitative measurement of semantic scale imbalance is proposed, which can accurately reflect model bias on multiple datasets, even on sample-balanced data, revealing a novel perspective for the study of class imbalance. Due to the prevalence of semantic scale imbalance, we propose semantic-scale-balanced learning, including a general loss improvement scheme and a dynamic re-weighting training framework that overcomes the challenge of calculating semantic scales in real-time during iterations. Comprehensive experiments show that dynamic semantic-scale-balanced learning consistently enables the model to perform superiorly on large-scale long-tailed and non-long-tailed natural and medical datasets, which is a good starting point for mitigating the prevalent but unnoticed model bias.
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