生物神经元比人工感知龙更强大,部分原因是复杂的树突状输入计算。启发是为了使感知器具有生物学启发的功能,我们探索了添加和调谐输入分支因子以及输入辍学的效果。这允许发现和基准测试参数有效的非线性输入体系结构。此外,我们提出了一个pytorch模块,以替换现有体系结构中的多层感知层。我们对MNIST分类的最初实验证明了与现有的感知架构相比,树突神经元的准确性和泛化改善。
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为了对线性不可分离的数据进行分类,神经元通常被组织成具有至少一个隐藏层的多层神经网络。灵感来自最近神经科学的发现,我们提出了一种新的神经元模型以及一种新的激活函数,可以使用单个神经元来学习非线性决策边界。我们表明标准神经元随后是新颖的顶端枝晶激活(ADA)可以使用100 \%的精度来学习XOR逻辑函数。此外,我们在计算机视觉,信号处理和自然语言处理中进行五个基准数据集进行实验,即摩洛哥,utkface,crema-d,时尚mnist和微小的想象成,表明ADA和泄漏的ADA功能提供了卓越的结果用于各种神经网络架构的整流线性单元(Relu),泄漏的Relu,RBF和嗖嗖声,例如单隐层或两个隐藏层的多层的Perceptrons(MLPS)和卷积神经网络(CNNS),如LENET,VGG,RESET和字符级CNN。当我们使用具有顶端树突激活(Pynada)的金字塔神经元改变神经元的标准模型时,我们获得进一步的性能改进。我们的代码可用于:https://github.com/raduionescu/pynada。
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The choice of activation functions and their motivation is a long-standing issue within the neural network community. Neuronal representations within artificial neural networks are commonly understood as logits, representing the log-odds score of presence of features within the stimulus. We derive logit-space operators equivalent to probabilistic Boolean logic-gates AND, OR, and XNOR for independent probabilities. Such theories are important to formalize more complex dendritic operations in real neurons, and these operations can be used as activation functions within a neural network, introducing probabilistic Boolean-logic as the core operation of the neural network. Since these functions involve taking multiple exponents and logarithms, they are computationally expensive and not well suited to be directly used within neural networks. Consequently, we construct efficient approximations named $\text{AND}_\text{AIL}$ (the AND operator Approximate for Independent Logits), $\text{OR}_\text{AIL}$, and $\text{XNOR}_\text{AIL}$, which utilize only comparison and addition operations, have well-behaved gradients, and can be deployed as activation functions in neural networks. Like MaxOut, $\text{AND}_\text{AIL}$ and $\text{OR}_\text{AIL}$ are generalizations of ReLU to two-dimensions. While our primary aim is to formalize dendritic computations within a logit-space probabilistic-Boolean framework, we deploy these new activation functions, both in isolation and in conjunction to demonstrate their effectiveness on a variety of tasks including image classification, transfer learning, abstract reasoning, and compositional zero-shot learning.
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We introduce DropConnect, a generalization of Dropout (Hinton et al., 2012), for regularizing large fully-connected layers within neural networks. When training with Dropout, a randomly selected subset of activations are set to zero within each layer. DropConnect instead sets a randomly selected subset of weights within the network to zero. Each unit thus receives input from a random subset of units in the previous layer. We derive a bound on the generalization performance of both Dropout and DropConnect. We then evaluate DropConnect on a range of datasets, comparing to Dropout, and show state-of-the-art results on several image recognition benchmarks by aggregating multiple DropConnect-trained models.
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神经网络体系结构的定义是执行最关键和最具挑战性的任务之一。在本文中,我们提出了平行密码。ParallelMLPS是一种可以通过探索现代CPU和GPU的局部性和并行功能的原理来实现具有不同数量神经元和激活功能的几个独立多层感知神经网络的训练。该技术的核心思想是使用修改的矩阵乘法,该矩阵乘法将序数矩阵乘法替换为两个简单的矩阵操作,这些矩阵操作允许梯度流动的单独且独立的路径,可以在其他情况下使用。我们已经在模拟数据集中评估了我们的算法,该数据集使用10,000种不同的模型来改变样品,功能和批次的数量。如果与顺序方法相比,我们实现了从1到4个数量级的训练速度。
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Computational units in artificial neural networks follow a simplified model of biological neurons. In the biological model, the output signal of a neuron runs down the axon, splits following the many branches at its end, and passes identically to all the downward neurons of the network. Each of the downward neurons will use their copy of this signal as one of many inputs dendrites, integrate them all and fire an output, if above some threshold. In the artificial neural network, this translates to the fact that the nonlinear filtering of the signal is performed in the upward neuron, meaning that in practice the same activation is shared between all the downward neurons that use that signal as their input. Dendrites thus play a passive role. We propose a slightly more complex model for the biological neuron, where dendrites play an active role: the activation in the output of the upward neuron becomes optional, and instead the signals going through each dendrite undergo independent nonlinear filterings, before the linear combination. We implement this new model into a ReLU computational unit and discuss its biological plausibility. We compare this new computational unit with the standard one and describe it from a geometrical point of view. We provide a Keras implementation of this unit into fully connected and convolutional layers and estimate their FLOPs and weights change. We then use these layers in ResNet architectures on CIFAR-10, CIFAR-100, Imagenette, and Imagewoof, obtaining performance improvements over standard ResNets up to 1.73%. Finally, we prove a universal representation theorem for continuous functions on compact sets and show that this new unit has more representational power than its standard counterpart.
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基于事件的视觉传感器在事件流中编码本地像素方面的亮度变化,而不是图像帧,并且除了低延迟,高动态范围和缺乏运动模糊之外,还产生稀疏,节能编码。基于事件的传感器的对象识别的最新进展来自深度神经网络的转换,培训背部经历。但是,使用这些事件流的方法需要转换到同步范式,这不仅失去了计算效率,而且还会错过提取时空特征的机会。在本文中,我们提出了一种用于基于事件的模式识别和对象检测的深度神经网络的端到端培训的混合架构,将尖刺神经网络(SNN)骨干组合用于高效的基于事件的特征提取,以及随后的模拟神经网络(ANN)头解决同步分类和检测任务。这是通过将标准的梯度训练与替代梯度训练相结合来实现这一点来实现,以通过SNN传播梯度。可以在不转换的情况下培训混合SNN-ANN,并且导致高度准确的网络,这些网络比其ANN对应物大得多。我们演示了基于事件的分类和对象检测数据集的结果,其中只需要将ANN头的体系结构适应任务,并且不需要基于事件的输入的转换。由于ANNS和SNNS需要不同的硬件范式来最大限度地提高其效率,因此设想SNN骨干网和ANN头可以在不同的处理单元上执行,从而分析在两部分之间进行通信的必要带宽。混合网络是有前途的架构,以进一步推进基于事件的愿景的机器学习方法,而不必妥协效率。
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This paper presents a novel technique based on gradient boosting to train the final layers of a neural network (NN). Gradient boosting is an additive expansion algorithm in which a series of models are trained sequentially to approximate a given function. A neural network can also be seen as an additive expansion where the scalar product of the responses of the last hidden layer and its weights provide the final output of the network. Instead of training the network as a whole, the proposed algorithm trains the network sequentially in $T$ steps. First, the bias term of the network is initialized with a constant approximation that minimizes the average loss of the data. Then, at each step, a portion of the network, composed of $J$ neurons, is trained to approximate the pseudo-residuals on the training data computed from the previous iterations. Finally, the $T$ partial models and bias are integrated as a single NN with $T \times J$ neurons in the hidden layer. Extensive experiments in classification and regression tasks, as well as in combination with deep neural networks, are carried out showing a competitive generalization performance with respect to neural networks trained with different standard solvers, such as Adam, L-BFGS, SGD and deep models. Furthermore, we show that the proposed method design permits to switch off a number of hidden units during test (the units that were last trained) without a significant reduction of its generalization ability. This permits the adaptation of the model to different classification speed requirements on the fly.
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本文提出了一种新的方法,称为模块化语法进化(MGE),以验证以下假设,即限制了神经进化的解决方案空间到模块化和简单的神经网络,可以有效地生成较小,更结构化的神经网络,同时提供可接受的(在某些方面)案例优于大型数据集的精度。 MGE还在两个方向上增强了最新的语法演化(GE)方法。首先,MGE的表示是模块化的,因为每个个体都有一组基因,并且每个基因都通过语法规则映射到神经元。其次,所提出的表示形式减轻了GE的两个重要缺点,即表示较低的表示性和弱位置,以生成具有大量神经元的模块化和多层网络。我们使用MGE定义和评估具有和不具有模块化的五种不同形式的结构,并找到没有耦合更有效的单层模块。我们的实验表明,模块化有助于更快地找到更好的神经网络。我们使用了十个具有不同尺寸,功能计数和输出类计数的众所周知的分类基准验证了提出的方法。我们的实验结果表明,MGE相对于现有的神经进化方法提供了卓越的准确性,并且返回分类器比其他机器学习生成的分类器要简单得多。最后,我们从经验上证明,MGE在局部性和可伸缩性属性方面优于其他GE方法。
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最近对反向传播的近似(BP)减轻了BP的许多计算效率低下和与生物学的不兼容性,但仍然存在重要的局限性。此外,近似值显着降低了基准的准确性,这表明完全不同的方法可能更富有成果。在这里,基于在软冠军全网络中Hebbian学习的最新理论基础上,我们介绍了多层softhebb,即一种训练深神经网络的算法,没有任何反馈,目标或错误信号。结果,它通过避免重量传输,非本地可塑性,层更新的时间锁定,迭代平衡以及(自我)监督或其他反馈信号来实现效率,这在其他方法中是必不可少的。与最先进的生物学知识学习相比,它提高的效率和生物兼容性不能取得准确性的折衷,而是改善了准确性。 MNIST,CIFAR-10,STL-10和IMAGENET上最多五个隐藏层和添加的线性分类器,分别达到99.4%,80.3%,76.2%和27.3%。总之,SOFTHEBB显示出与BP的截然不同的方法,即对几层的深度学习在大脑中可能是合理的,并提高了生物学上的机器学习的准确性。
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最近,稀疏的培训方法已开始作为事实上的人工神经网络的培训和推理效率的方法。然而,这种效率只是理论上。在实践中,每个人都使用二进制掩码来模拟稀疏性,因为典型的深度学习软件和硬件已针对密集的矩阵操作进行了优化。在本文中,我们采用正交方法,我们表明我们可以训练真正稀疏的神经网络以收获其全部潜力。为了实现这一目标,我们介绍了三个新颖的贡献,这些贡献是专门为稀疏神经网络设计的:(1)平行训练算法及其相应的稀疏实现,(2)具有不可训练的参数的激活功能,以支持梯度流动,以支持梯度流量, (3)隐藏的神经元对消除冗余的重要性指标。总而言之,我们能够打破记录并训练有史以来最大的神经网络在代表力方面训练 - 达到蝙蝠大脑的大小。结果表明,我们的方法具有最先进的表现,同时为环保人工智能时代开辟了道路。
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AI的一个关键挑战是构建体现的系统,该系统在动态变化的环境中运行。此类系统必须适应更改任务上下文并持续学习。虽然标准的深度学习系统实现了最先进的静态基准的结果,但它们通常在动态方案中挣扎。在这些设置中,来自多个上下文的错误信号可能会彼此干扰,最终导致称为灾难性遗忘的现象。在本文中,我们将生物学启发的架构调查为对这些问题的解决方案。具体而言,我们表明树突和局部抑制系统的生物物理特性使网络能够以特定于上下文的方式动态限制和路由信息。我们的主要贡献如下。首先,我们提出了一种新颖的人工神经网络架构,该架构将活跃的枝形和稀疏表示融入了标准的深度学习框架中。接下来,我们在需要任务的适应性的两个单独的基准上研究这种架构的性能:Meta-World,一个机器人代理必须学习同时解决各种操纵任务的多任务强化学习环境;和一个持续的学习基准,其中模型的预测任务在整个训练中都会发生变化。对两个基准的分析演示了重叠但不同和稀疏的子网的出现,允许系统流动地使用最小的遗忘。我们的神经实现标志在单一架构上第一次在多任务和持续学习设置上取得了竞争力。我们的研究揭示了神经元的生物学特性如何通知深度学习系统,以解决通常不可能对传统ANN来解决的动态情景。
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人工神经网络从其生物学对应物中汲取了很多灵感,成为我们最好的机器感知系统。这项工作总结了一些历史,并将现代理论神经科学纳入了深度学习领域的人工神经网络的实验。具体而言,迭代幅度修剪用于训练稀疏连接的网络,重量减少33倍而不会损失性能。这些用于测试并最终拒绝这样的假设:仅体重稀疏就可以改善图像噪声稳健性。最近的工作减轻了使用重量稀疏性,激活稀疏性和主动树突建模的灾难性遗忘。本文复制了这些发现,并扩展了培训卷积神经网络的方法,以更具挑战性的持续学习任务。该代码已公开可用。
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Exploring the climate impacts of various anthropogenic emissions scenarios is key to making informed decisions for climate change mitigation and adaptation. State-of-the-art Earth system models can provide detailed insight into these impacts, but have a large associated computational cost on a per-scenario basis. This large computational burden has driven recent interest in developing cheap machine learning models for the task of climate model emulation. In this manuscript, we explore the efficacy of randomly wired neural networks for this task. We describe how they can be constructed and compare them to their standard feedforward counterparts using the ClimateBench dataset. Specifically, we replace the serially connected dense layers in multilayer perceptrons, convolutional neural networks, and convolutional long short-term memory networks with randomly wired dense layers and assess the impact on model performance for models with 1 million and 10 million parameters. We find average performance improvements of 4.2% across model complexities and prediction tasks, with substantial performance improvements of up to 16.4% in some cases. Furthermore, we find no significant difference in prediction speed between networks with standard feedforward dense layers and those with randomly wired layers. These findings indicate that randomly wired neural networks may be suitable direct replacements for traditional dense layers in many standard models.
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Time Series Classification (TSC) is an important and challenging problem in data mining. With the increase of time series data availability, hundreds of TSC algorithms have been proposed. Among these methods, only a few have considered Deep Neural Networks (DNNs) to perform this task. This is surprising as deep learning has seen very successful applications in the last years. DNNs have indeed revolutionized the field of computer vision especially with the advent of novel deeper architectures such as Residual and Convolutional Neural Networks. Apart from images, sequential data such as text and audio can also be processed with DNNs to reach state-of-the-art performance for document classification and speech recognition. In this article, we study the current state-ofthe-art performance of deep learning algorithms for TSC by presenting an empirical study of the most recent DNN architectures for TSC. We give an overview of the most successful deep learning applications in various time series domains under a unified taxonomy of DNNs for TSC. We also provide an open source deep learning framework to the TSC community where we implemented each of the compared approaches and evaluated them on a univariate TSC benchmark (the UCR/UEA archive) and 12 multivariate time series datasets. By training 8,730 deep learning models on 97 time series datasets, we propose the most exhaustive study of DNNs for TSC to date.
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深度学习文献通过新的架构和培训技术不断更新。然而,尽管有一些关于随机权重的发现,但最近的研究却忽略了重量初始化。另一方面,最近的作品一直在接近网络科学,以了解训练后人工神经网络(ANN)的结构和动态。因此,在这项工作中,我们分析了随机初始化网络中神经元的中心性。我们表明,较高的神经元强度方差可能会降低性能,而较低的神经元强度方差通常会改善它。然后,提出了一种新方法,根据其强度根据优先附着(PA)规则重新连接神经元连接,从而大大降低了通过常见方法初始化的层的强度方差。从这个意义上讲,重新布线仅重新组织连接,同时保留权重的大小和分布。我们通过对图像分类进行的广泛统计分析表明,在使用简单和复杂的体系结构和学习时间表时,在大多数情况下,在培训和测试过程中,性能都会提高。我们的结果表明,除了规模外,权重的组织也与更好的初始化初始化有关。
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We introduce a method to train Quantized Neural Networks (QNNs) -neural networks with extremely low precision (e.g., 1-bit) weights and activations, at run-time. At traintime the quantized weights and activations are used for computing the parameter gradients. During the forward pass, QNNs drastically reduce memory size and accesses, and replace most arithmetic operations with bit-wise operations. As a result, power consumption is expected to be drastically reduced. We trained QNNs over the MNIST, CIFAR-10, SVHN and ImageNet datasets. The resulting QNNs achieve prediction accuracy comparable to their 32-bit counterparts. For example, our quantized version of AlexNet with 1-bit weights and 2-bit activations achieves 51% top-1 accuracy. Moreover, we quantize the parameter gradients to 6-bits as well which enables gradients computation using only bit-wise operation. Quantized recurrent neural networks were tested over the Penn Treebank dataset, and achieved comparable accuracy as their 32-bit counterparts using only 4-bits. Last but not least, we programmed a binary matrix multiplication GPU kernel with which it is possible to run our MNIST QNN 7 times faster than with an unoptimized GPU kernel, without suffering any loss in classification accuracy. The QNN code is available online.
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纯粹后的损害评估对于管理资源分配和执行有效响应至关重要。传统上,这种评估是通过野外侦察进行的,该侦察速度缓慢,危险且艰巨。取而代之的是,在本文中,我们进一步提出了通过卷积神经网络实施深度学习的想法,以便将建筑物的后卫星卫星图像分类为被洪水/损坏或未损坏的。该实验是在2017年哈维飓风之后使用的,该数据集采用了一个包含大休斯顿地区的纯种后卫星图像的数据集进行。本文实施了三个卷积神经网络模型体系结构,并配对了其他模型考虑,以实现高精度(超过99%),(超过99%),,超过99%),(超过99%)加强在殖民后灾难评估中有效使用机器学习。
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An activation function has a significant impact on the efficiency and robustness of the neural networks. As an alternative, we evolved a cutting-edge non-monotonic activation function, Negative Stimulated Hybrid Activation Function (Nish). It acts as a Rectified Linear Unit (ReLU) function for the positive region and a sinus-sigmoidal function for the negative region. In other words, it incorporates a sigmoid and a sine function and gaining new dynamics over classical ReLU. We analyzed the consistency of the Nish for different combinations of essential networks and most common activation functions using on several most popular benchmarks. From the experimental results, we reported that the accuracy rates achieved by the Nish is slightly better than compared to the Mish in classification.
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由于稀疏神经网络通常包含许多零权重,因此可以在不降低网络性能的情况下潜在地消除这些不必要的网络连接。因此,设计良好的稀疏神经网络具有显着降低拖鞋和计算资源的潜力。在这项工作中,我们提出了一种新的自动修剪方法 - 稀疏连接学习(SCL)。具体地,重量被重新参数化为可培训权重变量和二进制掩模的元素方向乘法。因此,由二进制掩模完全描述网络连接,其由单位步进函数调制。理论上,从理论上证明了使用直通估计器(STE)进行网络修剪的基本原理。这一原则是STE的代理梯度应该是积极的,确保掩模变量在其最小值处收敛。在找到泄漏的Relu后,SoftPlus和Identity Stes可以满足这个原理,我们建议采用SCL的身份STE以进行离散面膜松弛。我们发现不同特征的面具梯度非常不平衡,因此,我们建议将每个特征的掩模梯度标准化以优化掩码变量训练。为了自动训练稀疏掩码,我们将网络连接总数作为我们的客观函数中的正则化术语。由于SCL不需要由网络层设计人员定义的修剪标准或超级参数,因此在更大的假设空间中探讨了网络,以实现最佳性能的优化稀疏连接。 SCL克服了现有自动修剪方法的局限性。实验结果表明,SCL可以自动学习并选择各种基线网络结构的重要网络连接。 SCL培训的深度学习模型以稀疏性,精度和减少脚波特的SOTA人类设计和自动修剪方法训练。
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