Question

我已经开始实施Nguyen Widrow算法（如下所示），它似乎运行正常，但我有一些后续问题：

这看起来是正确的实现吗？
Nguyen Widrow初始化是否适用于任何网络拓扑/ 大小？（即5层AutoEncoder）
Nguyen Widrow初始化对任何输入范围都有效吗？（0/1，-1 / + 1等）
Nguyen Widrow初始化对任何激活函数都有效吗？（即Logistic，Tanh，Linear）

以下代码假设网络已经被随机化为-1 / + 1：

        ' Calculate the number of hidden neurons
        Dim HiddenNeuronsCount As Integer = Me.TotalNeuronsCount - (Me.InputsCount - Me.OutputsCount)

        ' Calculate the Beta value for all hidden layers
        Dim Beta As Double = (0.7 * Math.Pow(HiddenNeuronsCount, (1.0 / Me.InputsCount)))

        ' Loop through each layer in neural network, skipping input layer
        For i As Integer = 1 To Layers.GetUpperBound(0)

            ' Loop through each neuron in layer
            For j As Integer = 0 To Layers(i).Neurons.GetUpperBound(0)

                Dim InputsNorm As Double = 0

                ' Loop through each weight in neuron inputs, add weight value to InputsNorm
                For k As Integer = 0 To Layers(i).Neurons(j).ConnectionWeights.GetUpperBound(0)
                    InputsNorm += Layers(i).Neurons(j).ConnectionWeights(k) * Layers(i).Neurons(j).ConnectionWeights(k)
                Next

                ' Add bias value to InputsNorm
                InputsNorm += Layers(i).Neurons(j).Bias * Layers(i).Neurons(j).Bias

                ' Finalize euclidean norm calculation
                InputsNorm = Math.Sqrt(InputsNorm)

                ' Loop through each weight in neuron inputs, scale the weight based on euclidean norm and beta
                For k As Integer = 0 To Layers(i).Neurons(j).ConnectionWeights.GetUpperBound(0)
                    Layers(i).Neurons(j).ConnectionWeights(k) = (Beta * Layers(i).Neurons(j).ConnectionWeights(k)) / InputsNorm
                Next

                ' Scale the bias based on euclidean norm and beta
                Layers(i).Neurons(j).Bias = (Beta * Layers(i).Neurons(j).Bias) / InputsNorm

            Next

        Next

Answer 1

Nguyen＆amp; Widrow在他们的论文中假设输入介于-1和+1之间。 Nguyen Widrow初始化对任何长度有限的激活函数都有效。在他们的论文中，他们只讨论了一个2层NN，不确定是否有5层NN。

取值

神经网络初始化 - Nguyen Widrow实现？

1 个答案: