神经结构搜索(NAS)的成功受到过度计算要求的限制。虽然现代重量共享NAS方法,例如飞镖在单位数GPU天中可以完成搜索,但从共享权重中提取最终的最佳架构是众所周知的不可靠性。培训 - 速度估计(TSE),最近开发的普遍开发的普遍估计,以贝叶斯边缘似然解释的用来代替飞镖基于梯度优化的验证损失。这可以防止飞镖跳过连接崩溃,这显着提高了NASBench-201和原始飞镖搜索空间的性能。我们通过应用各种飞镖诊断来扩展这些结果,并显示不使用验证集产生的几种不寻常的行为。此外,我们的实验产生了在与操作选择相比,尽管通常在文献中受到有限的关注,但仍会产生对搜索性能的强烈影响的深度间隙和拓扑选择的具体示例。
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近年来,可微弱的建筑搜索(飞镖)已经受到了大量的关注,主要是因为它通过重量分享和连续放松来显着降低计算成本。然而,更近期的作品发现现有的可分辨率NAS技术难以俯视幼稚基线,产生劣化架构作为搜索所需。本文通过将体系结构权重放入高斯分布,而不是直接优化架构参数,而不是直接优化架构参数,而是作为分布学习问题。通过利用自然梯度变分推理(NGVI),可以基于现有的码票来容易地优化架构分布而不会产生更多内存和计算消耗。我们展示了贝叶斯原则的可分解NAS如何益处,提高勘探和提高稳定性。 NAS-BENCH-201和NAS-BENCH-1SHOT1基准数据集的实验结果证实了所提出的框架可以制造的重要改进。此外,我们还在学习参数上只需简单地应用argmax,我们进一步利用了NAS中最近提出的无培训代理,从优化分布中汲取的组架构中选择最佳架构,从而实现最终的架构-ART在NAS-BENCH-201和NAS-BENCH-1SHOT1基准上的结果。我们在飞镖搜索空间中的最佳架构也会分别获得2.37 \%,15.72 \%和24.2 \%的竞争性测试错误,分别在Cifar-10,CiFar-100和Imagenet数据集上。
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This paper addresses the scalability challenge of architecture search by formulating the task in a differentiable manner. Unlike conventional approaches of applying evolution or reinforcement learning over a discrete and non-differentiable search space, our method is based on the continuous relaxation of the architecture representation, allowing efficient search of the architecture using gradient descent. Extensive experiments on CIFAR-10, ImageNet, Penn Treebank and WikiText-2 show that our algorithm excels in discovering high-performance convolutional architectures for image classification and recurrent architectures for language modeling, while being orders of magnitude faster than state-of-the-art non-differentiable techniques. Our implementation has been made publicly available to facilitate further research on efficient architecture search algorithms.
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Neural architecture search (NAS) is a promising research direction that has the potential to replace expert-designed networks with learned, task-specific architectures. In this work, in order to help ground the empirical results in this field, we propose new NAS baselines that build off the following observations: (i) NAS is a specialized hyperparameter optimization problem; and (ii) random search is a competitive baseline for hyperparameter optimization. Leveraging these observations, we evaluate both random search with early-stopping and a novel random search with weight-sharing algorithm on two standard NAS benchmarks-PTB and CIFAR-10. Our results show that random search with early-stopping is a competitive NAS baseline, e.g., it performs at least as well as ENAS [41], a leading NAS method, on both benchmarks. Additionally, random search with weight-sharing outperforms random search with early-stopping, achieving a state-of-the-art NAS result on PTB and a highly competitive result on CIFAR-10. Finally, we explore the existing reproducibility issues of published NAS results. We note the lack of source material needed to exactly reproduce these results, and further discuss the robustness of published results given the various sources of variability in NAS experimental setups. Relatedly, we provide all information (code, random seeds, documentation) needed to exactly reproduce our results, and report our random search with weight-sharing results for each benchmark on multiple runs.
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可区分架构搜索(飞镖)是基于解决双重优化问题的数据驱动神经网络设计的有效方法。尽管在许多体系结构搜索任务中取得了成功,但仍然担心一阶飞镖的准确性和二阶飞镖的效率。在本文中,我们制定了单个级别的替代方案和放松的体系结构搜索(RARTS)方法,该方法通过数据和网络拆分利用整个数据集在体系结构学习中,而无需涉及相应损失功能(如飞镖)的混合第二个衍生物。在我们制定网络拆分的过程中,两个具有不同但相关权重的网络在寻找共享体系结构时进行了合作。 RART比飞镖的优势通过收敛定理和可解析的模型证明是合理的。此外,RART在准确性和搜索效率方面优于飞镖及其变体,如足够的实验结果所示。对于搜索拓扑结构(即边缘和操作)的任务,RART获得了比CIFAR-10上的二阶Darts更高的精度和60 \%的计算成本降低。转移到Imagenet时,RART继续超越表演飞镖,并且与最近的飞镖变体相提并论,尽管我们的创新纯粹是在训练算法上,而无需修改搜索空间。对于搜索宽度的任务,即卷积层中的频道数量,RARTS还优于传统的网络修剪基准。关于公共体系结构搜索基准等NATS BENCH的进一步实验也支持RARTS的优势。
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在NAS领域中,可分构造的架构搜索是普遍存在的,因为它的简单性和效率,其中两个范例,多路径算法和单路径方法主导。多路径框架(例如,DARTS)是直观的,但遭受内存使用和培训崩溃。单路径方法(例如,e.g.gdas和proxylesnnas)减轻了内存问题并缩小了搜索和评估之间的差距,但牺牲了性能。在本文中,我们提出了一种概念上简单的且有效的方法来桥接这两个范式,称为相互意识的子图可差架构搜索(MSG-DAS)。我们框架的核心是一个可分辨动的Gumbel-Topk采样器,它产生多个互斥的单路径子图。为了缓解多个子图形设置所带来的Severer Skip-Connect问题,我们提出了一个Dropblock-Identity模块来稳定优化。为了充分利用可用的型号(超级网和子图),我们介绍了一种记忆高效的超净指导蒸馏,以改善培训。所提出的框架击中了灵活的内存使用和搜索质量之间的平衡。我们展示了我们在想象中和CIFAR10上的方法的有效性,其中搜索的模型显示了与最近的方法相当的性能。
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虽然可分辨率的架构搜索(飞镖)已成为神经结构中的主流范例(NAS),因为其简单和效率,最近的作品发现,搜索架构的性能几乎可以随着飞镖的优化程序而增加,以及最终的大小由飞镖获得几乎无法表明运营的重要性。上述观察表明,飞镖中的监督信号可能是架构搜索的穷人或不可靠的指标,鼓励有趣和有趣的方向:我们可以衡量不可分辨率范式下的任何培训的运作重要性吗?我们通过在初始化问题的网络修剪中定制NAS提供肯定的答案。随着最近建议的突触突触效力标准在初始化的网络修剪中,我们寻求在没有任何培训的情况下将候选人行动中的候选人行动的重要性进行评分,并提出了一种名为“免费可分辨的架构搜索}(Freedarts)的小说框架” 。我们表明,没有任何培训,具有不同代理度量的自由路由器可以在不同的搜索空间中优于大多数NAS基线。更重要的是,Freedarts是非常内存的高效和计算效率,因为它放弃了架构搜索阶段的培训,使得能够在更灵活的空间上执行架构搜索并消除架构搜索和评估之间的深度间隙。我们希望我们的工作激励从初始化修剪的角度来激发解决NAS的尝试。
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神经结构中的标准范例(NAS)是搜索具有特定操作和连接的完全确定性体系结构。在这项工作中,我们建议寻找最佳运行分布,从而提供了一种随机和近似解,可用于采样任意长度的架构。我们提出并显示,给定架构单元格,其性能主要取决于使用的操作的比率,而不是典型的搜索空间中的任何特定连接模式;也就是说,操作排序的小变化通常是无关紧要的。这种直觉与任何特定的搜索策略都具有正交,并且可以应用于多样化的NAS算法。通过对4数据集和4个NAS技术的广泛验证(贝叶斯优化,可分辨率搜索,本地搜索和随机搜索),我们表明操作分布(1)保持足够的辨别力来可靠地识别解决方案,并且(2)显着识别比传统的编码更容易优化,导致大量速度,几乎没有成本性能。实际上,这种简单的直觉显着降低了电流方法的成本,并可能使NAS用于更广泛的应用中。
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This work targets designing a principled and unified training-free framework for Neural Architecture Search (NAS), with high performance, low cost, and in-depth interpretation. NAS has been explosively studied to automate the discovery of top-performer neural networks, but suffers from heavy resource consumption and often incurs search bias due to truncated training or approximations. Recent NAS works start to explore indicators that can predict a network's performance without training. However, they either leveraged limited properties of deep networks, or the benefits of their training-free indicators are not applied to more extensive search methods. By rigorous correlation analysis, we present a unified framework to understand and accelerate NAS, by disentangling "TEG" characteristics of searched networks - Trainability, Expressivity, Generalization - all assessed in a training-free manner. The TEG indicators could be scaled up and integrated with various NAS search methods, including both supernet and single-path approaches. Extensive studies validate the effective and efficient guidance from our TEG-NAS framework, leading to both improved search accuracy and over 56% reduction in search time cost. Moreover, we visualize search trajectories on three landscapes of "TEG" characteristics, observing that while a good local minimum is easier to find on NAS-Bench-201 given its simple topology, balancing "TEG" characteristics is much harder on the DARTS search space due to its complex landscape geometry. Our code is available at https://github.com/VITA-Group/TEGNAS.
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Conventional neural architecture search (NAS) approaches are based on reinforcement learning or evolutionary strategy, which take more than 3000 GPU hours to find a good model on CIFAR-10. We propose an efficient NAS approach learning to search by gradient descent. Our approach represents the search space as a directed acyclic graph (DAG). This DAG contains billions of sub-graphs, each of which indicates a kind of neural architecture. To avoid traversing all the possibilities of the sub-graphs, we develop a differentiable sampler over the DAG. This sampler is learnable and optimized by the validation loss after training the sampled architecture. In this way, our approach can be trained in an end-to-end fashion by gradient descent, named Gradient-based search using Differentiable Architecture Sampler (GDAS). In experiments, we can finish one searching procedure in four GPU hours on CIFAR-10, and the discovered model obtains a test error of 2.82% with only 2.5M parameters, which is on par with the state-of-the-art. Code is publicly available on GitHub: https://github.com/D-X-Y/NAS-Projects.
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可区分的架构搜索(飞镖)大大促进了NAS技术的发展,因为其搜索效率很高,但遭受了性能崩溃的影响。在本文中,我们努力从两个方面减轻飞镖的性能崩溃问题。首先,我们研究了飞镖中超级网的表达能力,然后仅使用训练batchnorm来得出新的飞镖范式设置。其次,从理论上讲,随机特征稀释了跳过连接在超网优化中的辅助连接作用,并使搜索算法专注于更公平的操作选择,从而解决了性能崩溃问题。我们具有随机功能的实例化飞镖和PC-Darts,分别为每个命名的RF-Darts和RF-PCDART构建一个改进的版本。实验结果表明,RF-darts在CIFAR-10上获得\ TextBf {94.36 \%}测试精度(这是NAS Bench-201的最接近最佳结果),并实现了最新的最新最先进的TOP-1从CIFAR-10传输时,ImageNet上\ TextBf {24.0 \%}的测试错误。此外,RF-DARTS在三个数据集(CIFAR-10,CIFAR-100和SVHN)和四个搜索空间(S1-S4)上进行稳健性能。此外,RF-PCDARTS在Imagenet上取得了更好的结果,即\ textbf {23.9 \%} top-1和\ textbf {7.1 \%} top-5 top-5测试错误,超越了代表性的方法,例如单路径,训练免费, ,直接在Imagenet上搜索部分通道范例。
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The automated machine learning (AutoML) field has become increasingly relevant in recent years. These algorithms can develop models without the need for expert knowledge, facilitating the application of machine learning techniques in the industry. Neural Architecture Search (NAS) exploits deep learning techniques to autonomously produce neural network architectures whose results rival the state-of-the-art models hand-crafted by AI experts. However, this approach requires significant computational resources and hardware investments, making it less appealing for real-usage applications. This article presents the third version of Pareto-Optimal Progressive Neural Architecture Search (POPNASv3), a new sequential model-based optimization NAS algorithm targeting different hardware environments and multiple classification tasks. Our method is able to find competitive architectures within large search spaces, while keeping a flexible structure and data processing pipeline to adapt to different tasks. The algorithm employs Pareto optimality to reduce the number of architectures sampled during the search, drastically improving the time efficiency without loss in accuracy. The experiments performed on images and time series classification datasets provide evidence that POPNASv3 can explore a large set of assorted operators and converge to optimal architectures suited for the type of data provided under different scenarios.
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Deep Learning has enabled remarkable progress over the last years on a variety of tasks, such as image recognition, speech recognition, and machine translation. One crucial aspect for this progress are novel neural architectures. Currently employed architectures have mostly been developed manually by human experts, which is a time-consuming and errorprone process. Because of this, there is growing interest in automated neural architecture search methods. We provide an overview of existing work in this field of research and categorize them according to three dimensions: search space, search strategy, and performance estimation strategy.
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与其他基于架构的NAS方法不同,广泛的神经结构搜索(BNA)提出了一个广泛的,它由卷积和增强块组成,被称为广泛的卷积神经网络(BCNN)作为搜索空间,以惊人的效率改进。 BCNN重用卷积块中的单元格的拓扑,使得BNA可以使用很少的小区以获得有效的搜索。此外,提出了多尺度特征融合和知识嵌入,以提高BCNN具有浅层拓扑的性能。然而,BNA遭受了一些缺点:1)特征融合和增强的代表性多样性不足,2)人类专家对知识嵌入设计的耗时。在本文中,我们提出了堆叠的BNA,其搜索空间是名为堆叠BCNN的开发的广泛可扩展架构,性能比BNA更好。一方面,堆叠的BCNN将Mini-BCNN视为保存综合表示的基本块,并提供强大的特征提取能力。另一方面,我们提出了知识嵌入搜索(KES)来学习适当的知识嵌入。实验结果表明,1)堆叠的BNA获得比BNA,2)KES有助于降低具有令人满意的性能的学习架构参数,3)堆叠BNA可提供0.02 GPU天的最新效率。
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可微分的架构搜索逐渐成为神经结构中的主流研究主题,以实现与早期NAS(基于EA的RL的)方法相比提高效率的能力。最近的可分辨率NAS还旨在进一步提高搜索效率,降低GPU记忆消耗,并解决“深度间隙”问题。然而,这些方法不再能够解决非微弱目标,更不用说多目标,例如性能,鲁棒性,效率和其他指标。我们提出了一个端到端的架构搜索框架,朝向非微弱的目标TND-NAS,具有在多目标NAs(MNA)中的不同NAS框架中的高效率的优点和兼容性的兼容性(MNA)。在可分辨率的NAS框架下,随着搜索空间的连续放松,TND-NAS具有在离散空间中优化的架构参数($ \ alpha $),同时通过$ \ alpha $逐步缩小超缩小的搜索策略。我们的代表性实验需要两个目标(参数,准确性),例如,我们在CIFAR10上实现了一系列高性能紧凑型架构(1.09米/ 3.3%,2.4M / 2.95%,9.57M / 2.54%)和CIFAR100(2.46 M / 18.3%,5.46 / 16.73%,12.88 / 15.20%)数据集。有利地,在现实世界的情景下(资源受限,平台专用),TND-NA可以方便地达到Pareto-Optimal解决方案。
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We propose Efficient Neural Architecture Search (ENAS), a fast and inexpensive approach for automatic model design. ENAS constructs a large computational graph, where each subgraph represents a neural network architecture, hence forcing all architectures to share their parameters. A controller is trained with policy gradient to search for a subgraph that maximizes the expected reward on a validation set. Meanwhile a model corresponding to the selected subgraph is trained to minimize a canonical cross entropy loss. Sharing parameters among child models allows ENAS to deliver strong empirical performances, whilst using much fewer GPU-hours than existing automatic model design approaches, and notably, 1000x less expensive than standard Neural Architecture Search. On Penn Treebank, ENAS discovers a novel architecture that achieves a test perplexity of 56.3, on par with the existing state-of-the-art among all methods without post-training processing. On CIFAR-10, ENAS finds a novel architecture that achieves 2.89% test error, which is on par with the 2.65% test error of NASNet (Zoph et al., 2018).
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作为梯度引导的搜索方法,可区分的神经体系结构搜索(飞镖)大大降低了计算成本,并加快了搜索的速度。在飞镖中,将体系结构参数引入候选操作,但是某些配备权重的操作的参数可能在初始阶段训练不好,这会导致候选操作之间的不公平竞争。无重量的操作大量出现,导致性能崩溃现象。此外,在训练超网中将占用许多内存,这会导致内存利用率较低。在本文中,提出了基于通道注意的部分通道连接,以进行可区分的神经体系结构搜索(ADARTS)。一些具有较高权重的通道是通过注意机制选择的,并将其他通道直接与处理的通道接触到操作空间。选择一些具有较高注意力权重的通道可以更好地将重要的功能信息传输到搜索空间中,并大大提高搜索效率和内存利用率。也可以避免由随机选择引起的网络结构的不稳定性。实验结果表明,ADART在CIFAR-10和CIFAR-100上分别达到了2.46%和17.06%的分类错误率。 Adarts可以有效地解决一个问题,即搜索过程中出现过多的跳过连接并获得具有更好性能的网络结构。
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我们提出了一个模型不确定性感知的可区分架构搜索($ \ mu $ darts),该搜索优化神经网络以同时达到高精度和低不确定性。我们在DARTS单元中引入混凝土辍学,并在训练损失中包括一个蒙特卡洛正规器,以优化混凝土辍学概率。在验证损失中引入了预测差异项,以使搜索具有最小模型不确定性的体系结构。与现有的DARTS方法相比,CIFAR10,CIFAR100,SVHN和ImageNet上的实验验证了$ \ MU $ $ $ $ $ $的实验。此外,与从现有的飞镖方法获得的体系结构相比,从$ \ mu $ darts获得的最终体系结构显示出更高的噪声稳健性。
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现有的神经结构搜索算法主要在具有短距离连接的搜索空间上。我们争辩说,这种设计虽然安全稳定,障碍搜索算法从探索更复杂的情景。在本文中,我们在具有长距离连接的复杂搜索空间上构建搜索算法,并显示现有的权重共享搜索算法由于存在\ TextBF {交织连接}而大部分失败。基于观察,我们介绍了一个名为\ textbf {if-nas}的简单且有效的算法,在那里我们在搜索过程中执行定期采样策略来构建不同的子网,避免在任何中的交织连接出现。在所提出的搜索空间中,IF-NAS优于随机采样和先前的重量共享搜索算法,通过显着的余量。 IF-NAS还推广到微单元的空间,这些空间更容易。我们的研究强调了宏观结构的重要性,我们期待沿着这个方向进一步努力。
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关于神经体系结构搜索(NAS)的现有研究主要集中于有效地搜索具有更好性能的网络体系结构。几乎没有取得进展,以系统地了解NAS搜索的架构是否对隐私攻击是强大的,而丰富的工作已经表明,人类设计的架构容易受到隐私攻击。在本文中,我们填补了这一空白,并系统地衡量了NAS体系结构的隐私风险。利用我们的测量研究中的见解,我们进一步探索了基于细胞的NAS架构的细胞模式,并评估细胞模式如何影响NAS搜索架构的隐私风险。通过广泛的实验,我们阐明了如何针对隐私攻击设计强大的NAS体系结构,还提供了一种通用方法,以了解NAS搜索的体系结构与其他隐私风险之间的隐藏相关性。
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