[{"createTime":1735734952000,"id":1,"img":"hwy_ms_500_252.jpeg","link":"https://activity.huaweicloud.com/cps.html?fromacct=261f35b6-af54-4511-a2ca-910fa15905d1&utm_source=V1g3MDY4NTY=&utm_medium=cps&utm_campaign=201905","name":"华为云秒杀","status":9,"txt":"华为云38元秒杀","type":1,"updateTime":1735747411000,"userId":3},{"createTime":1736173885000,"id":2,"img":"txy_480_300.png","link":"https://cloud.tencent.com/act/cps/redirect?redirect=1077&cps_key=edb15096bfff75effaaa8c8bb66138bd&from=console","name":"腾讯云秒杀","status":9,"txt":"腾讯云限量秒杀","type":1,"updateTime":1736173885000,"userId":3},{"createTime":1736177492000,"id":3,"img":"aly_251_140.png","link":"https://www.aliyun.com/minisite/goods?userCode=pwp8kmv3","memo":"","name":"阿里云","status":9,"txt":"阿里云2折起","type":1,"updateTime":1736177492000,"userId":3},{"createTime":1735660800000,"id":4,"img":"vultr_560_300.png","link":"https://www.vultr.com/?ref=9603742-8H","name":"Vultr","status":9,"txt":"Vultr送$100","type":1,"updateTime":1735660800000,"userId":3},{"createTime":1735660800000,"id":5,"img":"jdy_663_320.jpg","link":"https://3.cn/2ay1-e5t","name":"京东云","status":9,"txt":"京东云特惠专区","type":1,"updateTime":1735660800000,"userId":3},{"createTime":1735660800000,"id":6,"img":"new_ads.png","link":"https://www.iodraw.com/ads","name":"发布广告","status":9,"txt":"发布广告","type":1,"updateTime":1735660800000,"userId":3},{"createTime":1735660800000,"id":7,"img":"yun_910_50.png","link":"https://activity.huaweicloud.com/discount_area_v5/index.html?fromacct=261f35b6-af54-4511-a2ca-910fa15905d1&utm_source=aXhpYW95YW5nOA===&utm_medium=cps&utm_campaign=201905","name":"底部","status":9,"txt":"高性能云服务器2折起","type":2,"updateTime":1735660800000,"userId":3}]
学深度学习怎么可能学不到BN呢?今天就记录一下,学BN学到的一些知识。个人笔记,欢迎指点。
原论文:《Batch Normalization: Accelerating Deep Network Training by Reducing
Internal Covariate Shift》
Batch Normalization的目的是使我们的feature map满足均值为0,方差为1的分布规律。
这里所说满足某一分布规律并不是指某一个feature map的数据要满足分布规律,理论上是指整个训练样本集所对应feature map的数据要满足分布规律。
对于一个拥有d维的输入x,我们将对它的每一个维度进行标准化处理
下图为论文中给出的公式:
我们刚刚有说让feature map满足某一分布规律,理论上是指整个训练样本集所对应feature
map的数据要满足分布规律,也就是说要计算出整个训练集的feature
map然后在进行标准化处理,对于一个大型的数据集明显是不可能的,所以论文中说的是Batch
Normalization,也就是我们计算一个Batch数据的feature
map然后在进行标准化(batch越大越接近整个数据集的分布,效果越好)。我们根据上图的公式可以知道代表着我们计算的feature
map每个维度(channel)的均值,注意是一个向量不是一个值,向量的每一个元素代表着一个维度(channel)的均值。代表着我们计算的feature
map每个维度(channel)的方差,注意是一个向量不是一个值,向量的每一个元素代表着一个维度(channel)的方差,然后根据和计算标准化处理后得到的值。
在原论文公式中还有,两个参数吗?是的,是用来调整数值分布的方差大小,是用来调节数值均值的位置。这两个参数是在反向传播过程中学习得到的,的默认值是1,
的默认值是0。