尽管人工智能模型的进步,神经网络仍然无法实现人的表现,部分原因是由于信息是如何编码,并与人脑处理分歧。在一个人工神经网络(ANN)信息是使用统计方法来表示和处理为拟合函数,使在图像,文本和语音处理处理的结构模式。然而,实质性的变化的数据,例如统计特性,扭转的图像的背景,显着降低性能。在这里,我们提出了一个量子叠加扣球量子机制和现象在大脑中,它能够处理图像背景色的反转激发神经网络(QS-SNN)。的QS-SNN结合量子理论与脑启发从计算的角度来看尖峰神经网络模型,从而产生更鲁棒的性能与传统的人工神经网络模型进行比较,处理嘈杂输入时尤其如此。这里给出的结果将成为今后努力开发大脑启发的人工智能。
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由于其强大的时空信息表示能力,尖峰神经网络(SNN)引起了很多关注。胶囊神经网络(CAPSNET)在不同级别的组装和耦合功能方面做得好。在这里,我们通过将胶囊引入尖刺神经网络的建模来提出尖峰帽。此外,我们提出了更具生物合理的尖峰定时依赖性可塑性路线机构。通过充分考虑低水平尖峰胶囊与高级尖峰胶囊之间的时空关系,它们之间的耦合能力进一步提高。我们在Mnist和FashionMnist数据集上进行了验证的实验。与其他优秀的SNN模型相比,我们的算法仍然实现了高性能。我们的尖峰帽完全结合了SNN和Capsnet的增强,并对噪声和仿射变换表现出强大的稳健性。通过向测试数据集添加不同的盐胡椒和高斯噪声,实验结果表明,当有更多的噪音时,我们的尖峰帽显示出更强大的性能,而人工神经网络无法正确澄清。同样,我们的尖峰帽显示出强烈的概括,可以在漂式数据集上仿射转换。
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尖峰神经网络(SNN)引起了脑启发的人工智能和计算神经科学的广泛关注。它们可用于在多个尺度上模拟大脑中的生物信息处理。更重要的是,SNN是适当的抽象水平,可以将大脑和认知的灵感带入人工智能。在本文中,我们介绍了脑启发的认知智力引擎(Braincog),用于创建脑启发的AI和脑模拟模型。 Braincog将不同类型的尖峰神经元模型,学习规则,大脑区域等作为平台提供的重要模块。基于这些易于使用的模块,BrainCog支持各种受脑启发的认知功能,包括感知和学习,决策,知识表示和推理,运动控制和社会认知。这些受脑启发的AI模型已在各种受监督,无监督和强化学习任务上有效验证,并且可以用来使AI模型具有多种受脑启发的认知功能。为了进行大脑模拟,Braincog实现了决策,工作记忆,神经回路的结构模拟以及小鼠大脑,猕猴大脑和人脑的整个大脑结构模拟的功能模拟。一个名为BORN的AI引擎是基于Braincog开发的,它演示了如何将Braincog的组件集成并用于构建AI模型和应用。为了使科学追求解码生物智能的性质并创建AI,Braincog旨在提供必要且易于使用的构件,并提供基础设施支持,以开发基于脑部的尖峰神经网络AI,并模拟认知大脑在多个尺度上。可以在https://github.com/braincog-x上找到Braincog的在线存储库。
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这项研究提出了依赖电压突触可塑性(VDSP),这是一种新型的脑启发的无监督的本地学习规则,用于在线实施HEBB对神经形态硬件的可塑性机制。拟议的VDSP学习规则仅更新了突触后神经元的尖峰的突触电导,这使得相对于标准峰值依赖性可塑性(STDP)的更新数量减少了两倍。此更新取决于突触前神经元的膜电位,该神经元很容易作为神经元实现的一部分,因此不需要额外的存储器来存储。此外,该更新还对突触重量进行了正规化,并防止重复刺激时的重量爆炸或消失。进行严格的数学分析以在VDSP和STDP之间达到等效性。为了验证VDSP的系统级性能,我们训练一个单层尖峰神经网络(SNN),以识别手写数字。我们报告85.01 $ \ pm $ 0.76%(平均$ \ pm $ s.d。)对于MNIST数据集中的100个输出神经元网络的精度。在缩放网络大小时,性能会提高(400个输出神经元的89.93 $ \ pm $ 0.41%,500个神经元为90.56 $ \ pm $ 0.27),这验证了大规模计算机视觉任务的拟议学习规则的适用性。有趣的是,学习规则比STDP更好地适应输入信号的频率,并且不需要对超参数进行手动调整。
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Event-based simulations of Spiking Neural Networks (SNNs) are fast and accurate. However, they are rarely used in the context of event-based gradient descent because their implementations on GPUs are difficult. Discretization with the forward Euler method is instead often used with gradient descent techniques but has the disadvantage of being computationally expensive. Moreover, the lack of precision of discretized simulations can create mismatches between the simulated models and analog neuromorphic hardware. In this work, we propose a new exact error-backpropagation through spikes method for SNNs, extending Fast \& Deep to multiple spikes per neuron. We show that our method can be efficiently implemented on GPUs in a fully event-based manner, making it fast to compute and precise enough for analog neuromorphic hardware. Compared to the original Fast \& Deep and the current state-of-the-art event-based gradient-descent algorithms, we demonstrate increased performance on several benchmark datasets with both feedforward and convolutional SNNs. In particular, we show that multi-spike SNNs can have advantages over single-spike networks in terms of convergence, sparsity, classification latency and sensitivity to the dead neuron problem.
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Spiking neural networks (SNN) are a viable alternative to conventional artificial neural networks when energy efficiency and computational complexity are of importance. A major advantage of SNNs is their binary information transfer through spike trains. The training of SNN has, however, been a challenge, since neuron models are non-differentiable and traditional gradient-based backpropagation algorithms cannot be applied directly. Furthermore, spike-timing-dependent plasticity (STDP), albeit being a spike-based learning rule, updates weights locally and does not optimize for the output error of the network. We present desire backpropagation, a method to derive the desired spike activity of neurons from the output error. The loss function can then be evaluated locally for every neuron. Incorporating the desire values into the STDP weight update leads to global error minimization and increasing classification accuracy. At the same time, the neuron dynamics and computational efficiency of STDP are maintained, making it a spike-based supervised learning rule. We trained three-layer networks to classify MNIST and Fashion-MNIST images and reached an accuracy of 98.41% and 87.56%, respectively. Furthermore, we show that desire backpropagation is computationally less complex than backpropagation in traditional neural networks.
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脑启发的尖峰神经网络(SNN)已成功应用于许多模式识别域。基于SNN的深层结构在感知任务(例如图像分类,目标检测)中取得了可观的结果。但是,深SNN在加强学习(RL)任务中的应用仍然是一个问题。尽管以前有关于SNN和RL组合的研究,但其中大多数专注于浅网络的机器人控制问题,或使用ANN-SNN转换方法来实施Spiking Spiking Deep Q Network(SDQN)。在这项工作中,我们数学分析了SDQN中尖峰信号特征消失的问题,并提出了一种基于潜在的层归一化(PBLN)方法,以直接训练尖峰尖峰深度Q网络。实验表明,与最先进的ANN-SNN转换方法和其他SDQN作品相比,建议的PBLN Spiking Deep Q Networks(PL-SDQN)在Atari游戏任务上取得了更好的性能。
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最近的研究表明,卷积神经网络(CNNS)不是图像分类的唯一可行的解决方案。此外,CNN中使用的重量共享和反向验证不对应于预测灵长类动物视觉系统中存在的机制。为了提出更加生物合理的解决方案,我们设计了使用峰值定时依赖性塑性(STDP)和其奖励调制变体(R-STDP)学习规则训练的本地连接的尖峰神经网络(SNN)。使用尖刺神经元和局部连接以及强化学习(RL)将我们带到了所提出的架构中的命名法生物网络。我们的网络由速率编码的输入层组成,后跟局部连接的隐藏层和解码输出层。采用尖峰群体的投票方案进行解码。我们使用Mnist DataSet获取图像分类准确性,并评估我们有益于于不同目标响应的奖励系统的稳健性。
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Emergence of deep neural networks (DNNs) has raised enormous attention towards artificial neural networks (ANNs) once again. They have become the state-of-the-art models and have won different machine learning challenges. Although these networks are inspired by the brain, they lack biological plausibility, and they have structural differences compared to the brain. Spiking neural networks (SNNs) have been around for a long time, and they have been investigated to understand the dynamics of the brain. However, their application in real-world and complicated machine learning tasks were limited. Recently, they have shown great potential in solving such tasks. Due to their energy efficiency and temporal dynamics there are many promises in their future development. In this work, we reviewed the structures and performances of SNNs on image classification tasks. The comparisons illustrate that these networks show great capabilities for more complicated problems. Furthermore, the simple learning rules developed for SNNs, such as STDP and R-STDP, can be a potential alternative to replace the backpropagation algorithm used in DNNs.
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为了在专门的神经形态硬件中进行节能计算,我们提出了尖峰神经编码,这是基于预测性编码理论的人工神经模型家族的实例化。该模型是同类模型,它是通过在“猜测和检查”的永无止境过程中运行的,神经元可以预测彼此的活动值,然后调整自己的活动以做出更好的未来预测。我们系统的互动性,迭代性质非常适合感官流预测的连续时间表述,并且如我们所示,模型的结构产生了局部突触更新规则,可以用来补充或作为在线峰值定位的替代方案依赖的可塑性。在本文中,我们对模型的实例化进行了实例化,该模型包括泄漏的集成和火灾单元。但是,我们系统所在的框架自然可以结合更复杂的神经元,例如Hodgkin-Huxley模型。我们在模式识别方面的实验结果证明了当二进制尖峰列车是通信间通信的主要范式时,模型的潜力。值得注意的是,尖峰神经编码在分类绩效方面具有竞争力,并且在从任务序列中学习时会降低遗忘,从而提供了更经济的,具有生物学上的替代品,可用于流行的人工神经网络。
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我们提出了一种新的学习算法,使用传统的人工神经网络(ANN)作为代理训练尖刺神经网络(SNN)。我们分别与具有相同网络架构和共享突触权重的集成和火(IF)和Relu神经元进行两次SNN和ANN网络。两个网络的前进通过完全独立。通过假设具有速率编码的神经元作为Relu的近似值,我们将SNN中的SNN的误差进行了回复,以更新共享权重,只需用SNN的ANN最终输出替换ANN最终输出。我们将建议的代理学习应用于深度卷积的SNNS,并在Fahion-Mnist和CiFar10的两个基准数据集上进行评估,分别为94.56%和93.11%的分类准确性。所提出的网络可以优于培训的其他深鼻涕,训练,替代学习,代理梯度学习,或从深处转换。转换的SNNS需要长时间的仿真时间来达到合理的准确性,而我们的代理学习导致高效的SNN,模拟时间较短。
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We propose a novel backpropagation algorithm for training spiking neural networks (SNNs) that encodes information in the relative multiple spike timing of individual neurons without single-spike restrictions. The proposed algorithm inherits the advantages of conventional timing-based methods in that it computes accurate gradients with respect to spike timing, which promotes ideal temporal coding. Unlike conventional methods where each neuron fires at most once, the proposed algorithm allows each neuron to fire multiple times. This extension naturally improves the computational capacity of SNNs. Our SNN model outperformed comparable SNN models and achieved as high accuracy as non-convolutional artificial neural networks. The spike count property of our networks was altered depending on the time constant of the postsynaptic current and the membrane potential. Moreover, we found that there existed the optimal time constant with the maximum test accuracy. That was not seen in conventional SNNs with single-spike restrictions on time-to-fast-spike (TTFS) coding. This result demonstrates the computational properties of SNNs that biologically encode information into the multi-spike timing of individual neurons. Our code would be publicly available.
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In the past years, artificial neural networks (ANNs) have become the de-facto standard to solve tasks in communications engineering that are difficult to solve with traditional methods. In parallel, the artificial intelligence community drives its research to biology-inspired, brain-like spiking neural networks (SNNs), which promise extremely energy-efficient computing. In this paper, we investigate the use of SNNs in the context of channel equalization for ultra-low complexity receivers. We propose an SNN-based equalizer with a feedback structure akin to the decision feedback equalizer (DFE). For conversion of real-world data into spike signals we introduce a novel ternary encoding and compare it with traditional log-scale encoding. We show that our approach clearly outperforms conventional linear equalizers for three different exemplary channels. We highlight that mainly the conversion of the channel output to spikes introduces a small performance penalty. The proposed SNN with a decision feedback structure enables the path to competitive energy-efficient transceivers.
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Deep spiking neural networks (SNNs) offer the promise of low-power artificial intelligence. However, training deep SNNs from scratch or converting deep artificial neural networks to SNNs without loss of performance has been a challenge. Here we propose an exact mapping from a network with Rectified Linear Units (ReLUs) to an SNN that fires exactly one spike per neuron. For our constructive proof, we assume that an arbitrary multi-layer ReLU network with or without convolutional layers, batch normalization and max pooling layers was trained to high performance on some training set. Furthermore, we assume that we have access to a representative example of input data used during training and to the exact parameters (weights and biases) of the trained ReLU network. The mapping from deep ReLU networks to SNNs causes zero percent drop in accuracy on CIFAR10, CIFAR100 and the ImageNet-like data sets Places365 and PASS. More generally our work shows that an arbitrary deep ReLU network can be replaced by an energy-efficient single-spike neural network without any loss of performance.
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Spiking neural networks (SNNs) are receiving increasing attention due to their low power consumption and strong bio-plausibility. Optimization of SNNs is a challenging task. Two main methods, artificial neural network (ANN)-to-SNN conversion and spike-based backpropagation (BP), both have their advantages and limitations. For ANN-to-SNN conversion, it requires a long inference time to approximate the accuracy of ANN, thus diminishing the benefits of SNN. With spike-based BP, training high-precision SNNs typically consumes dozens of times more computational resources and time than their ANN counterparts. In this paper, we propose a novel SNN training approach that combines the benefits of the two methods. We first train a single-step SNN by approximating the neural potential distribution with random noise, then convert the single-step SNN to a multi-step SNN losslessly. The introduction of Gaussian distributed noise leads to a significant gain in accuracy after conversion. The results show that our method considerably reduces the training and inference times of SNNs while maintaining their high accuracy. Compared to the previous two methods, ours can reduce training time by 65%-75% and achieves more than 100 times faster inference speed. We also argue that the neuron model augmented with noise makes it more bio-plausible.
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尖峰神经网络(SNN)已成为用于分类任务的硬件有效体系结构。基于尖峰的编码的惩罚是缺乏完全使用尖峰执行的通用训练机制。已经进行了几项尝试,用于采用在非加速人工神经网络(ANN)中使用的强大反向传播(BP)技术:(1)SNN可以通过外部计算的数值梯度来训练。 (2)基于天然尖峰的学习的主要进步是使用具有分阶段的前向/向后传递的尖峰时间依赖性可塑性(STDP)的近似反向传播。但是,在此类阶段之间的信息传输需要外部内存和计算访问。这是神经形态硬件实现的挑战。在本文中,我们提出了一种基于随机SNN的后式Prop(SSNN-BP)算法,该算法利用复合神经元同时计算前向通行激活,并用尖峰明确计算前向传递梯度。尽管签名的梯度值是基于SPIKE的表示的挑战,但我们通过将梯度信号分为正和负流来解决这一问题。复合神经元以随机尖峰传播的形式编码信息,并将反向传播的权重更新转换为时间和空间上局部离散的STDP类似STDP的Spike Concike更新,使其与硬件友好的电阻式处理单元(RPU)兼容。此外,我们的方法使用足够长的尖峰训练来接近BP ANN基线。最后,我们表明,可以通过强制执行胜利者的抑制性横向连接来实现软磁体交叉渗透损失函数。我们的SNN通过与MNIST,时尚和扩展的MNIST数据集的ANN相当的性能来表现出极好的概括。因此,SSNN-BP可以使BP与纯粹基于尖峰的神经形态硬件兼容。
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图形卷积网络(GCN)由于学习图信息的显着表示能力而实现了令人印象深刻的性能。但是,GCN在深网上实施时需要昂贵的计算功率,因此很难将其部署在电池供电的设备上。相比之下,执行生物保真推理过程的尖峰神经网络(SNN)提供了节能的神经结构。在这项工作中,我们提出了SpikingGCN,这是一个端到端框架,旨在将GCN的嵌入与SNN的生物层性特征相结合。原始图数据根据图形卷积的合并编码为尖峰列车。我们通过利用与神经元节点结合的完全连接的层来进一步对生物信息处理进行建模。在各种场景(例如引用网络,图像图分类和推荐系统)中,我们的实验结果表明,该方法可以针对最新方法获得竞争性能。此外,我们表明,在神经形态芯片上的SpikingGCN可以将能源效率的明显优势带入图形数据分析中,这表明了其构建环境友好的机器学习模型的巨大潜力。
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在连续学习期间,人工神经网络(ANNS)经历灾难性的遗忘(CF)。相比之下,大脑可以在没有任何灾难性遗忘的迹象的情况下连续学习。尖峰神经网络(SNNS)是下一代ANN,具有从生物神经网络借入的许多功能。因此,SNNS可能希望更好地适应CF。在本文中,我们研究SNNS对CF的易感性,并测试几种用于减轻灾难性遗忘的生物启发方法。 SNNS受到基于Spike-Timing依赖的塑性(STDP)的生物合理的本地培训规则。本地培训禁止基于全局损失函数的梯度直接使用CF防御方法。我们开发并测试了该方法,以确定基于随机Langevin动态的突触(重量)的重要性,而无需梯度。还测试了一种从模拟神经网络改编的灾难性遗忘预防的其他几种方法。实验是在Spyketorch环境中自由的数据集进行的。
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尖峰神经网络(SNNS)模仿大脑计算策略,并在时空信息处理中表现出很大的功能。作为人类感知的基本因素,视觉关注是指生物视觉系统中显着区域的动态选择过程。尽管视觉注意力的机制在计算机视觉上取得了巨大成功,但很少会引入SNN中。受到预测注意重新映射的实验观察的启发,我们在这里提出了一种新的时空通道拟合注意力(SCTFA)模块,该模块可以通过使用历史积累的空间通道信息来指导SNN有效地捕获潜在的目标区域。通过在三个事件流数据集(DVS手势,SL-Animals-DVS和MNIST-DVS)上进行系统评估,我们证明了带有SCTFA模块(SCTFA-SNN)的SNN不仅显着超过了基线SNN(BL-SNN)(BL-SNN)(BL-SNN)以及其他两个具有退化注意力模块的SNN模型,但也通过现有最新方法实现了竞争精度。此外,我们的详细分析表明,所提出的SCTFA-SNN模型对噪声和出色的稳定性具有强大的稳健性,同时保持了可接受的复杂性和效率。总体而言,这些发现表明,适当纳入大脑的认知机制可能会提供一种有希望的方法来提高SNN的能力。
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尖峰神经网络(SNN)在各种智能场景中都表现出了出色的功能。大多数现有的训练SNN方法基于突触可塑性的概念。但是,在现实的大脑中学习还利用了神经元的内在非突触机制。生物神经元的尖峰阈值是一种关键的固有神经元特征,在毫秒的时间尺度上表现出丰富的动力学,并已被认为是一种促进神经信息处理的基本机制。在这项研究中,我们开发了一种新型的协同学习方法,该方法同时训练SNN中的突触权重和尖峰阈值。经过突触阈值协同学习(STL-SNN)训练的SNN在各种静态和神经形态数据集上的精度明显高于接受两种突触学习(SL)和阈值学习(TL)的单独学习模型(TL)的SNN。在训练过程中,协同学习方法优化了神经阈值,通过适当的触发速率为网络提供稳定的信号传输。进一步的分析表明,STL-SNN对嘈杂的数据是可靠的,并且对深网结构表现出低的能耗。此外,通过引入广义联合决策框架(JDF),可以进一步提高STL-SNN的性能。总体而言,我们的发现表明,突触和内在的非突触机制之间的生物学上合理的协同作用可能为开发高效的SNN学习方法提供了一种有希望的方法。
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