{"id":6190,"date":"2024-06-27T17:08:30","date_gmt":"2024-06-27T09:08:30","guid":{"rendered":"https:\/\/t.n-years.com\/?p=6190"},"modified":"2024-06-27T17:16:58","modified_gmt":"2024-06-27T09:16:58","slug":"%e6%bf%80%e6%b4%bb%e5%87%bd%e6%95%b0%e5%92%8c%e6%8d%9f%e5%a4%b1%e5%87%bd%e6%95%b0","status":"publish","type":"post","link":"https:\/\/t.n-years.com\/?p=6190","title":{"rendered":"\u6fc0\u6d3b\u51fd\u6570\u548c\u635f\u5931\u51fd\u6570"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">\u975e\u539f\u521b\u3001ChatGPT \u95ee\u7b54\u751f\u6210<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u6fc0\u6d3b\u51fd\u6570\u548c\u635f\u5931\u51fd\u6570\u662f\u795e\u7ecf\u7f51\u7edc\u4e2d\u4e24\u4e2a\u91cd\u8981\u4f46\u4e0d\u540c\u7684\u6982\u5ff5\uff0c\u5b83\u4eec\u5728\u6a21\u578b\u8bad\u7ec3\u548c\u6027\u80fd\u4f18\u5316\u4e2d\u8d77\u7740\u5173\u952e\u4f5c\u7528\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u6fc0\u6d3b\u51fd\u6570<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u6fc0\u6d3b\u51fd\u6570<\/strong>\uff08Activation Function\uff09\u7528\u4e8e\u795e\u7ecf\u7f51\u7edc\u4e2d\u7684\u6bcf\u4e2a\u795e\u7ecf\u5143\uff0c\u4ee5\u5f15\u5165\u975e\u7ebf\u6027\u3002\u5b83\u5c06\u795e\u7ecf\u5143\u7684\u8f93\u5165\u52a0\u6743\u6c42\u548c\u5e76\u6dfb\u52a0\u504f\u7f6e\u540e\u7684\u8f93\u51fa\u8fdb\u884c\u53d8\u6362\uff0c\u4ece\u800c\u4f7f\u795e\u7ecf\u7f51\u7edc\u80fd\u591f\u5b66\u4e60\u548c\u8868\u793a\u590d\u6742\u7684\u975e\u7ebf\u6027\u5173\u7cfb\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">\u5e38\u89c1\u7684\u6fc0\u6d3b\u51fd\u6570<\/h4>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Sigmoid<\/strong>\uff08S\u5f62\u51fd\u6570\uff09\uff1a<br>[<br>\\sigma(x) = \\frac{1}{1 + e^{-x}}<br>]<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u8f93\u51fa\u8303\u56f4\uff1a0 \u5230 1<\/li>\n\n\n\n<li>\u4f18\u70b9\uff1a\u5c06\u8f93\u51fa\u6620\u5c04\u5230 (0, 1) \u533a\u95f4\uff0c\u9002\u5408\u4e8e\u4e8c\u5206\u7c7b\u95ee\u9898\u3002<\/li>\n\n\n\n<li>\u7f3a\u70b9\uff1a\u5bb9\u6613\u5bfc\u81f4\u68af\u5ea6\u6d88\u5931\u95ee\u9898\u3002<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Tanh<\/strong>\uff08\u53cc\u66f2\u6b63\u5207\u51fd\u6570\uff09\uff1a<br><code>[<br>\\tanh(x) = \\frac{e^x - e^{-x}}{e^x + e^{-x}}<br>]<\/code><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u8f93\u51fa\u8303\u56f4\uff1a-1 \u5230 1<\/li>\n\n\n\n<li>\u4f18\u70b9\uff1a\u8f93\u51fa\u5747\u503c\u4e3a0\uff0c\u6bd4 Sigmoid \u66f4\u597d\u3002<\/li>\n\n\n\n<li>\u7f3a\u70b9\uff1a\u4e5f\u4f1a\u6709\u68af\u5ea6\u6d88\u5931\u95ee\u9898\u3002<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>ReLU<\/strong>\uff08Rectified Linear Unit\uff09\uff1a<br>[<br>\\text{ReLU}(x) = \\max(0, x)<br>]<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u8f93\u51fa\u8303\u56f4\uff1a0 \u5230\u6b63\u65e0\u7a77<\/li>\n\n\n\n<li>\u4f18\u70b9\uff1a\u89e3\u51b3\u68af\u5ea6\u6d88\u5931\u95ee\u9898\uff0c\u8ba1\u7b97\u7b80\u5355\u9ad8\u6548\u3002<\/li>\n\n\n\n<li>\u7f3a\u70b9\uff1a\u5bb9\u6613\u5bfc\u81f4\u201c\u6b7b\u4ea1 ReLU\u201d\u95ee\u9898\uff08\u795e\u7ecf\u5143\u8f93\u51fa\u6052\u4e3a0\uff09\u3002<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Leaky ReLU<\/strong>\uff1a<br>[<br>\\text{Leaky ReLU}(x) = \\begin{cases}<br>x &amp; \\text{if } x &gt; 0 \\<br>\\alpha x &amp; \\text{if } x \\leq 0<br>\\end{cases}<br>]<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u8f93\u51fa\u8303\u56f4\uff1a0 \u5230\u6b63\u65e0\u7a77<\/li>\n\n\n\n<li>\u4f18\u70b9\uff1a\u7f13\u89e3\u201c\u6b7b\u4ea1 ReLU\u201d\u95ee\u9898\u3002<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Softmax<\/strong>\uff1a<br>[<br>\\text{Softmax}(x_i) = \\frac{e^{x_i}}{\\sum_{j} e^{x_j}}<br>]<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u8f93\u51fa\u8303\u56f4\uff1a0 \u5230 1<\/li>\n\n\n\n<li>\u4f18\u70b9\uff1a\u7528\u4e8e\u591a\u5206\u7c7b\u95ee\u9898\uff0c\u5c06\u8f93\u51fa\u8f6c\u6362\u4e3a\u6982\u7387\u5206\u5e03\u3002<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">\u635f\u5931\u51fd\u6570<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u635f\u5931\u51fd\u6570<\/strong>\uff08Loss Function\uff09\uff0c\u4e5f\u79f0\u4e3a\u76ee\u6807\u51fd\u6570\u6216\u4ee3\u4ef7\u51fd\u6570\uff0c\u7528\u4e8e\u8861\u91cf\u6a21\u578b\u9884\u6d4b\u503c\u4e0e\u5b9e\u9645\u503c\u4e4b\u95f4\u7684\u5dee\u8ddd\u3002\u5b83\u662f\u6a21\u578b\u4f18\u5316\u8fc7\u7a0b\u4e2d\u9700\u8981\u6700\u5c0f\u5316\u7684\u76ee\u6807\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">\u5e38\u89c1\u7684\u635f\u5931\u51fd\u6570<\/h4>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u5747\u65b9\u8bef\u5dee\uff08MSE\uff09<\/strong>\uff1a<br>[<br>\\text{MSE} = \\frac{1}{n} \\sum_{i=1}^n (y_i - \\hat{y}_i)^2<br>]<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u7528\u4e8e\u56de\u5f52\u95ee\u9898\uff0c\u8ba1\u7b97\u9884\u6d4b\u503c\u4e0e\u5b9e\u9645\u503c\u4e4b\u95f4\u7684\u5e73\u65b9\u8bef\u5dee\u3002<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u5747\u65b9\u6839\u8bef\u5dee\uff08RMSE\uff09<\/strong>\uff1a<br>[<br>\\text{RMSE} = \\sqrt{\\frac{1}{n} \\sum_{i=1}^n (y_i - \\hat{y}_i)^2}<br>]<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>MSE \u7684\u5e73\u65b9\u6839\uff0c\u66f4\u5177\u89e3\u91ca\u6027\uff0c\u5355\u4f4d\u4e0e\u539f\u6570\u636e\u4e00\u81f4\u3002<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u5e73\u5747\u7edd\u5bf9\u8bef\u5dee\uff08MAE\uff09<\/strong>\uff1a<br>[<br>\\text{MAE} = \\frac{1}{n} \\sum_{i=1}^n |y_i - \\hat{y}_i|<br>]<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u7528\u4e8e\u56de\u5f52\u95ee\u9898\uff0c\u8ba1\u7b97\u9884\u6d4b\u503c\u4e0e\u5b9e\u9645\u503c\u4e4b\u95f4\u7684\u7edd\u5bf9\u8bef\u5dee\u3002<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u4ea4\u53c9\u71b5\u635f\u5931\uff08Cross-Entropy Loss\uff09<\/strong>\uff1a<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u4e8c\u5206\u7c7b\u4ea4\u53c9\u71b5\uff1a<br>[<br>\\text{Binary Cross-Entropy} = -\\frac{1}{n} \\sum_{i=1}^n [y_i \\log(\\hat{y}_i) + (1 - y_i) \\log(1 - \\hat{y}_i)]<br>]<\/li>\n\n\n\n<li>\u591a\u5206\u7c7b\u4ea4\u53c9\u71b5\uff1a<br>[<br>\\text{Categorical Cross-Entropy} = -\\sum_{i=1}^n \\sum_{c=1}^C y_{i,c} \\log(\\hat{y}_{i,c})<br>]<\/li>\n\n\n\n<li>\u7528\u4e8e\u5206\u7c7b\u95ee\u9898\uff0c\u8861\u91cf\u9884\u6d4b\u6982\u7387\u5206\u5e03\u4e0e\u5b9e\u9645\u5206\u5e03\u4e4b\u95f4\u7684\u5dee\u5f02\u3002<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Huber \u635f\u5931<\/strong>\uff1a<br>[<br>L_\\delta(a) = \\begin{cases}<br>\\frac{1}{2}a^2 &amp; \\text{for } |a| \\leq \\delta \\<br>\\delta(|a| - \\frac{1}{2}\\delta) &amp; \\text{otherwise}<br>\\end{cases}<br>]<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u7ed3\u5408\u4e86 MAE \u548c MSE \u7684\u4f18\u70b9\uff0c\u9002\u7528\u4e8e\u5bf9\u5f02\u5e38\u503c\u9c81\u68d2\u7684\u56de\u5f52\u95ee\u9898\u3002<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">\u533a\u522b\u4e0e\u8054\u7cfb<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u4f5c\u7528\u4e0d\u540c<\/strong>\uff1a<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u6fc0\u6d3b\u51fd\u6570\u7528\u4e8e\u795e\u7ecf\u7f51\u7edc\u7684\u6bcf\u4e2a\u795e\u7ecf\u5143\uff0c\u4ee5\u5f15\u5165\u975e\u7ebf\u6027\uff0c\u4f7f\u7f51\u7edc\u80fd\u591f\u5b66\u4e60\u590d\u6742\u7684\u6a21\u5f0f\u3002<\/li>\n\n\n\n<li>\u635f\u5931\u51fd\u6570\u7528\u4e8e\u8861\u91cf\u6a21\u578b\u7684\u9884\u6d4b\u8bef\u5dee\uff0c\u5e76\u5728\u8bad\u7ec3\u8fc7\u7a0b\u4e2d\u5f15\u5bfc\u4f18\u5316\u7b97\u6cd5\uff08\u5982\u68af\u5ea6\u4e0b\u964d\uff09\u8c03\u6574\u6a21\u578b\u53c2\u6570\u4ee5\u6700\u5c0f\u5316\u8bef\u5dee\u3002<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u4f4d\u7f6e\u4e0d\u540c<\/strong>\uff1a<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u6fc0\u6d3b\u51fd\u6570\u4f4d\u4e8e\u795e\u7ecf\u7f51\u7edc\u7684\u6bcf\u4e00\u5c42\u795e\u7ecf\u5143\u4e2d\uff0c\u5f71\u54cd\u6bcf\u5c42\u7684\u8f93\u51fa\u3002<\/li>\n\n\n\n<li>\u635f\u5931\u51fd\u6570\u4f4d\u4e8e\u7f51\u7edc\u7684\u8f93\u51fa\u5c42\uff0c\u7528\u4e8e\u8ba1\u7b97\u6574\u4f53\u9884\u6d4b\u8bef\u5dee\u3002<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u5f71\u54cd\u4e0d\u540c<\/strong>\uff1a<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u6fc0\u6d3b\u51fd\u6570\u5f71\u54cd\u7f51\u7edc\u7684\u8bad\u7ec3\u8fc7\u7a0b\u548c\u6700\u7ec8\u8868\u73b0\uff0c\u662f\u7f51\u7edc\u7ed3\u6784\u7684\u4e00\u90e8\u5206\u3002<\/li>\n\n\n\n<li>\u635f\u5931\u51fd\u6570\u5f71\u54cd\u6a21\u578b\u7684\u4f18\u5316\u76ee\u6807\u548c\u5b66\u4e60\u8fc7\u7a0b\u7684\u65b9\u5411\u3002<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">\u793a\u4f8b<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u4e00\u4e2a\u7b80\u5355\u7684\u795e\u7ecf\u7f51\u7edc\u4e2d\uff0c\u6211\u4eec\u53ef\u4ee5\u540c\u65f6\u4f7f\u7528 ReLU \u6fc0\u6d3b\u51fd\u6570\u548c MSE \u635f\u5931\u51fd\u6570\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>import numpy as np\nimport tensorflow as tf\nfrom tensorflow.keras.models import Sequential\nfrom tensorflow.keras.layers import Dense\n\n# \u6784\u5efa\u7b80\u5355\u7684\u795e\u7ecf\u7f51\u7edc\nmodel = Sequential(&#91;\n    Dense(64, activation='relu', input_shape=(10,)),  # \u4f7f\u7528 ReLU \u4f5c\u4e3a\u6fc0\u6d3b\u51fd\u6570\n    Dense(64, activation='relu'),\n    Dense(1)\n])\n\n# \u7f16\u8bd1\u6a21\u578b\uff0c\u4f7f\u7528\u5747\u65b9\u8bef\u5dee\u4f5c\u4e3a\u635f\u5931\u51fd\u6570\nmodel.compile(optimizer='adam', loss='mse')\n\n# \u6a21\u62df\u6570\u636e\nX_train = np.random.rand(100, 10)\ny_train = np.random.rand(100)\n\n# \u8bad\u7ec3\u6a21\u578b\nmodel.fit(X_train, y_train, epochs=10)<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u8fd9\u4e2a\u793a\u4f8b\u4e2d\uff0c\u795e\u7ecf\u7f51\u7edc\u4f7f\u7528 ReLU \u6fc0\u6d3b\u51fd\u6570\u5f15\u5165\u975e\u7ebf\u6027\uff0c\u800c\u5747\u65b9\u8bef\u5dee\u635f\u5931\u51fd\u6570\u7528\u4e8e\u8861\u91cf\u9884\u6d4b\u503c\u4e0e\u5b9e\u9645\u503c\u4e4b\u95f4\u7684\u5dee\u8ddd\uff0c\u5e76\u6307\u5bfc\u6a21\u578b\u4f18\u5316\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u975e\u539f\u521b\u3001ChatGPT \u95ee\u7b54\u751f\u6210 \u6fc0\u6d3b\u51fd\u6570\u548c\u635f\u5931\u51fd\u6570\u662f\u795e\u7ecf\u7f51\u7edc\u4e2d\u4e24\u4e2a\u91cd\u8981\u4f46\u4e0d\u540c\u7684\u6982\u5ff5\uff0c\u5b83\u4eec\u5728\u6a21\u578b\u8bad\u7ec3\u548c\u6027\u80fd\u4f18\u5316&#8230; <\/p>\n<div class=\"read-more navbutton\"><a href=\"https:\/\/t.n-years.com\/?p=6190\">\u9605\u8bfb\u66f4\u591a<i class=\"fa fa-angle-double-right\"><\/i><\/a><\/div>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[95,86,93],"class_list":["post-6190","post","type-post","status-publish","format-standard","hentry","category-5","tag-95","tag-86","tag-93"],"_links":{"self":[{"href":"https:\/\/t.n-years.com\/index.php?rest_route=\/wp\/v2\/posts\/6190","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/t.n-years.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/t.n-years.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/t.n-years.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/t.n-years.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=6190"}],"version-history":[{"count":2,"href":"https:\/\/t.n-years.com\/index.php?rest_route=\/wp\/v2\/posts\/6190\/revisions"}],"predecessor-version":[{"id":6194,"href":"https:\/\/t.n-years.com\/index.php?rest_route=\/wp\/v2\/posts\/6190\/revisions\/6194"}],"wp:attachment":[{"href":"https:\/\/t.n-years.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=6190"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/t.n-years.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6190"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/t.n-years.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6190"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}