Early-exiting dynamic neural networks (EDNN), as one type of dynamic neural networks, has been widely studied recently. A typical EDNN has multiple prediction heads at different layers of the network backbone. During inference, the model will exit at either the last prediction head or an intermediate prediction head where the prediction confidence is higher than a predefined threshold. To optimize the model, these prediction heads together with the network backbone are trained on every batch of training data. This brings a train-test mismatch problem that all the prediction heads are optimized on all types of data in training phase while the deeper heads will only see difficult inputs in testing phase. Treating training and testing inputs differently at the two phases will cause the mismatch between training and testing data distributions. To mitigate this problem, we formulate an EDNN as an additive model inspired by gradient boosting, and propose multiple training techniques to optimize the model effectively. We name our method BoostNet. Our experiments show it achieves the state-of-the-art performance on CIFAR100 and ImageNet datasets in both anytime and budgeted-batch prediction modes. Our code is released at https://github.com/SHI-Labs/Boosted-Dynamic-Networks.

早期退出是提高深网推理效率的有效范例。通过构建具有不同资源需求的分类器（出口），此类网络可以在早期出口处输出简单的样本，从而消除了执行更深层的需求。尽管现有作品主要关注多EXIT网络的建筑设计，但此类模型的培训策略在很大程度上没有探索。当前的最新模型在培训期间对所有样品进行了相同的处理。但是，在测试过程中的早期外观行为被忽略了，从而导致训练和测试之间存在差距。在本文中，我们建议通过样品加权来弥合这一差距。从直觉上讲，简单的样品通常在推理期间在网络早期退出，应该为培训早期分类器提供更多贡献。但是，晚期分类器应强调硬样品的培训（主要是从更深层退出）。我们的工作建议采用一个体重预测网络，以加重每个出口处不同训练样本的损失。这个重量预测网络和骨干模型在具有新的优化目标的元学习框架下共同优化。通过将推断期间的适应性行为带入训练阶段，我们表明拟议的加权机制始终提高分类准确性和推理效率之间的权衡。代码可在https://github.com/leaplabthu/l2w-den上找到。

由于存储器和计算资源有限，部署在移动设备上的卷积神经网络（CNNS）是困难的。我们的目标是通过利用特征图中的冗余来设计包括CPU和GPU的异构设备的高效神经网络，这很少在神经结构设计中进行了研究。对于类似CPU的设备，我们提出了一种新颖的CPU高效的Ghost（C-Ghost）模块，以生成从廉价操作的更多特征映射。基于一组内在的特征映射，我们使用廉价的成本应用一系列线性变换，以生成许多幽灵特征图，可以完全揭示内在特征的信息。所提出的C-Ghost模块可以作为即插即用组件，以升级现有的卷积神经网络。 C-Ghost瓶颈旨在堆叠C-Ghost模块，然后可以轻松建立轻量级的C-Ghostnet。我们进一步考虑GPU设备的有效网络。在建筑阶段的情况下，不涉及太多的GPU效率（例如，深度明智的卷积），我们建议利用阶段明智的特征冗余来制定GPU高效的幽灵（G-GHOST）阶段结构。舞台中的特征被分成两个部分，其中使用具有较少输出通道的原始块处理第一部分，用于生成内在特征，另一个通过利用阶段明智的冗余来生成廉价的操作。在基准测试上进行的实验证明了所提出的C-Ghost模块和G-Ghost阶段的有效性。 C-Ghostnet和G-Ghostnet分别可以分别实现CPU和GPU的准确性和延迟的最佳权衡。代码可在https://github.com/huawei-noah/cv-backbones获得。

Deep neural networks have long training and processing times. Early exits added to neural networks allow the network to make early predictions using intermediate activations in the network in time-sensitive applications. However, early exits increase the training time of the neural networks. We introduce QuickNets: a novel cascaded training algorithm for faster training of neural networks. QuickNets are trained in a layer-wise manner such that each successive layer is only trained on samples that could not be correctly classified by the previous layers. We demonstrate that QuickNets can dynamically distribute learning and have a reduced training cost and inference cost compared to standard Backpropagation. Additionally, we introduce commitment layers that significantly improve the early exits by identifying for over-confident predictions and demonstrate its success.

动态神经网络是深度学习中的新兴的研究课题。与具有推断阶段的固定计算图和参数的静态模型相比，动态网络可以使其结构或参数适应不同的输入，从而在本调查中的准确性，计算效率，适应性等方面的显着优势。我们全面地通过将动态网络分为三个主要类别：1）使用数据相关的架构或参数进行处理的实例 - Wise-Wise DiveS动态模型的速度开发区域2）关于图像数据的不同空间位置和3）沿着诸如视频和文本的顺序数据的时间维度执行自适应推断的时间明智的动态模型进行自适应计算的空间 - 方向动态网络。系统地审查了动态网络的重要研究问题，例如架构设计，决策方案，优化技术和应用。最后，我们与有趣的未来研究方向讨论了该领域的开放问题。

深度卷积神经网络（CNNS）通常是复杂的设计，具有许多可学习的参数，用于准确性原因。为了缓解在移动设备上部署它们的昂贵成本，最近的作品使挖掘预定识别架构中的冗余作出了巨大努力。然而，尚未完全研究现代CNN的输入分辨率的冗余，即输入图像的分辨率是固定的。在本文中，我们观察到，用于准确预测给定图像的最小分辨率使用相同的神经网络是不同的。为此，我们提出了一种新颖的动态分辨率网络（DRNET），其中基于每个输入样本动态地确定输入分辨率。其中，利用所需网络共同地探索具有可忽略的计算成本的分辨率预测器。具体地，预测器学习可以保留的最小分辨率，并且甚至超过每个图像的原始识别准确性。在推断过程中，每个输入图像将被调整为其预测的分辨率，以最小化整体计算负担。然后，我们对几个基准网络和数据集进行了广泛的实验。结果表明，我们的DRNET可以嵌入到任何现成的网络架构中，以获得计算复杂性的相当大降低。例如，DR-RESET-50实现了类似的性能，计算减少约34％，同时增加了1.4％的准确度，与原始Resnet-50上的计算减少相比，在ImageNet上的原始resnet-50增加了10％。

目前，这是一个热门的研究主题，可以在深度学习和物联网技术的帮助下实现大量光谱数据的准确，高效和实时识别。深度神经网络在光谱分析中起着关键作用。但是，更深层模型的推断是以静态方式进行的，不能根据设备进行调整。并非所有样本都需要分配所有计算以实现自信的预测，这阻碍了最大化整体性能。为了解决上述问题，我们提出了一个具有自适应推理的光谱数据分类框架。具体而言，要为不同样本分配不同的计算，同时更好地利用不同设备之间的协作，我们利用早期外观体系结构，将中间分类器放置在架构的不同深度，并在预测置信度达到预设阈值时输出结果。我们提出了一个自我介绍学习的训练范式，最深的分类器对浅的分类器进行了软监督，以最大程度地提高其性能和训练速度。同时，为了减轻早期外观范式中中间分类器的位置和数字设置的性能脆弱性，我们提出了一个自适应的残留网络。它可以调整不同曲线位置下每个块中的层数，因此它可以专注于曲线的重要位置（例如：拉曼峰），并根据任务性能和计算资源准确地分配适当的计算预算。据我们所知，本文是首次尝试通过自适应推断物联网平台下的光谱检测来进行优化。我们进行了许多实验，实验结果表明，我们所提出的方法可以比现有方法实现更高的计算预算性能。

深神经网络（DNN）已成为许多应用程序域（包括基于Web的服务）的重要组成部分。这些服务需要高吞吐量和（接近）实时功能，例如，对用户的请求做出反应或反应，或者按时处理传入数据流。但是，DNN设计的趋势是朝着具有许多层和参数的较大模型，以实现更准确的结果。尽管这些模型通常是预先训练的，但是在如此大的模型中，计算复杂性仍然相对显着，从而阻碍了低推断潜伏期。实施缓存机制是用于加速服务响应时间的典型系统工程解决方案。但是，传统的缓存通常不适合基于DNN的服务。在本文中，我们提出了一种端到端自动化解决方案，以根据其计算复杂性和推理延迟来提高基于DNN的服务的性能。我们的缓存方法采用了DNN模型和早期出口的自我介绍的思想。提出的解决方案是一种自动化的在线层缓存机制，如果提前出口之一中的高速缓存模型足够有信心，则可以在推理时间提早退出大型模型。本文的主要贡献之一是，我们将该想法实施为在线缓存，这意味着缓存模型不需要访问培训数据，并且仅根据运行时的传入数据执行，使其适用于应用程序使用预训练的模型。我们的实验在两个下游任务（面部和对象分类）上结果表明，平均而言，缓存可以将这些服务的计算复杂性降低到58 \％（就FLOPS计数而言），并将其推断潜伏期提高到46 \％精度低至零至零。

Convolutional neural networks have been widely deployed in various application scenarios. In order to extend the applications' boundaries to some accuracy-crucial domains, researchers have been investigating approaches to boost accuracy through either deeper or wider network structures, which brings with them the exponential increment of the computational and storage cost, delaying the responding time.In this paper, we propose a general training framework named self distillation, which notably enhances the performance (accuracy) of convolutional neural networks through shrinking the size of the network rather than aggrandizing it. Different from traditional knowledge distillation -a knowledge transformation methodology among networks, which forces student neural networks to approximate the softmax layer outputs of pre-trained teacher neural networks, the proposed self distillation framework distills knowledge within network itself. The networks are firstly divided into several sections. Then the knowledge in the deeper portion of the networks is squeezed into the shallow ones. Experiments further prove the generalization of the proposed self distillation framework: enhancement of accuracy at average level is 2.65%, varying from 0.61% in ResNeXt as minimum to 4.07% in VGG19 as maximum. In addition, it can also provide flexibility of depth-wise scalable inference on resource-limited edge devices. Our codes will be released on github soon.

减少大深度学习模型的处理时间的问题是许多现实世界应用中的根本挑战。早期退出方法通过将附加内部分类器（IC）附加到神经网络的中间层来努力实现这一目标。 IC可以快速返回简单示例的预测，结果，降低整个模型的平均推理时间。但是，如果特定IC不决定早期回答，则其预测被丢弃，其计算有效地浪费。为了解决这个问题，我们引入零时间浪费（ZTW），这是一种新的方法，其中每个IC重用由其前辈返回的预测（1）在IC和（2）之间以相对于类似的方式组合先前输出之间的直接连接。我们对各个数据集和架构进行了广泛的实验，以证明ZTW实现了比最近提出的早期退出方法的其他更好的比例与推理时间权衡。

合奏学习结合了几个单独的模型，以获得更好的概括性能。目前，与浅层或传统模型相比，深度学习体系结构表现更好。深度合奏学习模型结合了深度学习模型以及整体学习的优势，使最终模型具有更好的概括性能。本文回顾了最先进的深度合奏模型，因此是研究人员的广泛摘要。合奏模型广泛地分类为包装，增强，堆叠，基于负相关的深度合奏模型，显式/隐式合奏，同质/异质合奏，基于决策融合策略的深层集合模型。还简要讨论了在不同领域中深层集成模型的应用。最后，我们以一些潜在的未来研究方向结束了本文。

Ensemble learning serves as a straightforward way to improve the performance of almost any machine learning algorithm. Existing deep ensemble methods usually naively train many different models and then aggregate their predictions. This is not optimal in our view from two aspects: i) Naively training multiple models adds much more computational burden, especially in the deep learning era; ii) Purely optimizing each base model without considering their interactions limits the diversity of ensemble and performance gains. We tackle these issues by proposing deep negative correlation classification (DNCC), in which the accuracy and diversity trade-off is systematically controlled by decomposing the loss function seamlessly into individual accuracy and the correlation between individual models and the ensemble. DNCC yields a deep classification ensemble where the individual estimator is both accurate and negatively correlated. Thanks to the optimized diversities, DNCC works well even when utilizing a shared network backbone, which significantly improves its efficiency when compared with most existing ensemble systems. Extensive experiments on multiple benchmark datasets and network structures demonstrate the superiority of the proposed method.

诸如智能手机和自治车辆的移动设备越来越依赖深神经网络（DNN）来执行复杂的推理任务，例如图像分类和语音识别等。但是，在移动设备上连续执行整个DNN可以快速消耗其电池。虽然任务卸载到云/边缘服务器可能会降低移动设备的计算负担，但信道质量，网络和边缘服务器负载中的不稳定模式可能导致任务执行的显着延迟。最近，已经提出了基于分割计算（SC）的方法，其中DNN被分成在移动设备上和边缘服务器上执行的头部和尾模型。最终，这可能会降低带宽使用以及能量消耗。另一种叫做早期退出（EE）的方法，列车模型在架构中呈现多个“退出”，每个都提供越来越高的目标准确性。因此，可以根据当前条件或应用需求进行准确性和延迟之间的权衡。在本文中，我们通过呈现最相关方法的比较，对SC和EE策略进行全面的综合调查。我们通过提供一系列引人注目的研究挑战来结束论文。

深度学习技术在各种任务中都表现出了出色的有效性，并且深度学习具有推进多种应用程序（包括在边缘计算中）的潜力，其中将深层模型部署在边缘设备上，以实现即时的数据处理和响应。一个关键的挑战是，虽然深层模型的应用通常会产生大量的内存和计算成本，但Edge设备通常只提供非常有限的存储和计算功能，这些功能可能会在各个设备之间差异很大。这些特征使得难以构建深度学习解决方案，以释放边缘设备的潜力，同时遵守其约束。应对这一挑战的一种有希望的方法是自动化有效的深度学习模型的设计，这些模型轻巧，仅需少量存储，并且仅产生低计算开销。该调查提供了针对边缘计算的深度学习模型设计自动化技术的全面覆盖。它提供了关键指标的概述和比较，这些指标通常用于量化模型在有效性，轻度和计算成本方面的水平。然后，该调查涵盖了深层设计自动化技术的三类最新技术：自动化神经体系结构搜索，自动化模型压缩以及联合自动化设计和压缩。最后，调查涵盖了未来研究的开放问题和方向。

Dynamic networks have been extensively explored as they can considerably improve the model's representation power with acceptable computational cost. The common practice in implementing dynamic networks is to convert given static layers into fully dynamic ones where all parameters are dynamic and vary with the input. Recent studies empirically show the trend that the more dynamic layers contribute to ever-increasing performance. However, such a fully dynamic setting 1) may cause redundant parameters and high deployment costs, limiting the applicability of dynamic networks to a broader range of tasks and models, and more importantly, 2) contradicts the previous discovery in the human brain that \textit{when human brains process an attention-demanding task, only partial neurons in the task-specific areas are activated by the input, while the rest neurons leave in a baseline state.} Critically, there is no effort to understand and resolve the above contradictory finding, leaving the primal question -- to make the computational parameters fully dynamic or not? -- unanswered. The main contributions of our work are challenging the basic commonsense in dynamic networks, and, proposing and validating the \textsc{cherry hypothesis} -- \textit{A fully dynamic network contains a subset of dynamic parameters that when transforming other dynamic parameters into static ones, can maintain or even exceed the performance of the original network.} Technically, we propose a brain-inspired partially dynamic network, namely PAD-Net, to transform the redundant dynamic parameters into static ones. Also, we further design Iterative Mode Partition to partition the dynamic- and static-subnet, which alleviates the redundancy in traditional fully dynamic networks. Our hypothesis and method are comprehensively supported by large-scale experiments with typical advanced dynamic methods.

While machine learning is traditionally a resource intensive task, embedded systems, autonomous navigation, and the vision of the Internet of Things fuel the interest in resource-efficient approaches. These approaches aim for a carefully chosen trade-off between performance and resource consumption in terms of computation and energy. The development of such approaches is among the major challenges in current machine learning research and key to ensure a smooth transition of machine learning technology from a scientific environment with virtually unlimited computing resources into everyday's applications. In this article, we provide an overview of the current state of the art of machine learning techniques facilitating these real-world requirements. In particular, we focus on deep neural networks (DNNs), the predominant machine learning models of the past decade. We give a comprehensive overview of the vast literature that can be mainly split into three non-mutually exclusive categories: (i) quantized neural networks, (ii) network pruning, and (iii) structural efficiency. These techniques can be applied during training or as post-processing, and they are widely used to reduce the computational demands in terms of memory footprint, inference speed, and energy efficiency. We also briefly discuss different concepts of embedded hardware for DNNs and their compatibility with machine learning techniques as well as potential for energy and latency reduction. We substantiate our discussion with experiments on well-known benchmark datasets using compression techniques (quantization, pruning) for a set of resource-constrained embedded systems, such as CPUs, GPUs and FPGAs. The obtained results highlight the difficulty of finding good trade-offs between resource efficiency and predictive performance.

Most of the existing works use projection functions for ternary quantization in discrete space. Scaling factors and thresholds are used in some cases to improve the model accuracy. However, the gradients used for optimization are inaccurate and result in a notable accuracy gap between the full precision and ternary models. To get more accurate gradients, some works gradually increase the discrete portion of the full precision weights in the forward propagation pass, e.g., using temperature-based Sigmoid function. Instead of directly performing ternary quantization in discrete space, we push full precision weights close to ternary ones through regularization term prior to ternary quantization. In addition, inspired by the temperature-based method, we introduce a re-scaling factor to obtain more accurate gradients by simulating the derivatives of Sigmoid function. The experimental results show that our method can significantly improve the accuracy of ternary quantization in both image classification and object detection tasks.

最近，已经成功地应用于各种遥感图像（RSI）识别任务的大量基于深度学习的方法。然而，RSI字段中深度学习方法的大多数现有进步严重依赖于手动设计的骨干网络提取的特征，这严重阻碍了由于RSI的复杂性以及先前知识的限制而受到深度学习模型的潜力。在本文中，我们研究了RSI识别任务中的骨干架构的新设计范式，包括场景分类，陆地覆盖分类和对象检测。提出了一种基于权重共享策略和进化算法的一拍架构搜索框架，称为RSBNet，其中包括三个阶段：首先，在层面搜索空间中构造的超空网是在自组装的大型中预先磨削 - 基于集合单路径培训策略进行缩放RSI数据集。接下来，预先培训的SuperNet通过可切换识别模块配备不同的识别头，并分别在目标数据集上进行微调，以获取特定于任务特定的超网络。最后，我们根据没有任何网络训练的进化算法，搜索最佳骨干架构进行不同识别任务。对于不同识别任务的五个基准数据集进行了广泛的实验，结果显示了所提出的搜索范例的有效性，并证明搜索后的骨干能够灵活地调整不同的RSI识别任务并实现令人印象深刻的性能。

Binary neural networks are the extreme case of network quantization, which has long been thought of as a potential edge machine learning solution. However, the significant accuracy gap to the full-precision counterparts restricts their creative potential for mobile applications. In this work, we revisit the potential of binary neural networks and focus on a compelling but unanswered problem: how can a binary neural network achieve the crucial accuracy level (e.g., 80%) on ILSVRC-2012 ImageNet? We achieve this goal by enhancing the optimization process from three complementary perspectives: (1) We design a novel binary architecture BNext based on a comprehensive study of binary architectures and their optimization process. (2) We propose a novel knowledge-distillation technique to alleviate the counter-intuitive overfitting problem observed when attempting to train extremely accurate binary models. (3) We analyze the data augmentation pipeline for binary networks and modernize it with up-to-date techniques from full-precision models. The evaluation results on ImageNet show that BNext, for the first time, pushes the binary model accuracy boundary to 80.57% and significantly outperforms all the existing binary networks. Code and trained models are available at: https://github.com/hpi-xnor/BNext.git.

标记医学图像取决于专业知识，因此很难在短时间内以高质量获取大量注释的医学图像。因此，在小型数据集中充分利用有限标记的样品来构建高性能模型是医疗图像分类问题的关键。在本文中，我们提出了一个深入监督的层选择性注意网络（LSANET），该网络全面使用功能级和预测级监督中的标签信息。对于特征级别的监督，为了更好地融合低级功能和高级功能，我们提出了一个新颖的视觉注意模块，层选择性注意（LSA），以专注于不同层的特征选择。 LSA引入了一种权重分配方案，该方案可以在整个训练过程中动态调整每个辅助分支的加权因子，以进一步增强深入监督的学习并确保其概括。对于预测级的监督，我们采用知识协同策略，通过成对知识匹配来促进所有监督分支之间的层次信息互动。使用公共数据集MedMnist，这是用于涵盖多种医学专业的生物医学图像分类的大规模基准，我们评估了LSANET在多个主流CNN体系结构和各种视觉注意模块上评估。实验结果表明，我们所提出的方法对其相应的对应物进行了实质性改进，这表明LSANET可以为医学图像分类领域的标签有效学习提供有希望的解决方案。