“`” \u53c2\u8003\u56de\u7b54\uff1a<\/p>\n
Focal loss\u4e3b\u8981\u662f\u4e3a\u4e86\u89e3\u51b3one-stage\u76ee\u6807\u68c0\u6d4b\u4e2d\u6b63\u8d1f\u6837\u672c\u6bd4\u4f8b\u4e25\u91cd\u5931\u8861\u7684\u95ee\u9898\u3002\u8be5\u635f\u5931\u51fd\u6570\u964d\u4f4e\u4e86\u5927\u91cf\u7b80\u5355\u8d1f\u6837\u672c\u5728\u8bad\u7ec3\u4e2d\u6240\u5360\u7684\u6743\u91cd\uff0c\u4e5f\u53ef\u7406\u89e3\u4e3a\u4e00\u79cd\u56f0\u96be\u6837\u672c\u6316\u6398\u3002<\/p>\n
\u635f\u5931\u51fd\u6570\u5f62\u5f0f\uff1aFocal loss\u662f\u5728\u4ea4\u53c9\u71b5\u635f\u5931\u51fd\u6570\u57fa\u7840\u4e0a\u8fdb\u884c\u7684\u4fee\u6539\uff0c\u9996\u5148\u56de\u987e\u4e8c\u5206\u7c7b\u4ea4\u53c9\u4e0a\u635f\u5931\uff1a<\/p>\n
<img alt=""img"" referrerpolicy=""no-referrer"" src=""https:\/\/uploadfiles.nowcoder.com\/images\/20190315\/311436_1552657534871_E429E38DB287AE3F7F68AD1172A48606""><\/p>\n
\u662f\u7ecf\u8fc7\u6fc0\u6d3b\u51fd\u6570\u7684\u8f93\u51fa\uff0c\u6240\u4ee5\u57280-1\u4e4b\u95f4\u3002\u53ef\u89c1\u666e\u901a\u7684\u4ea4\u53c9\u71b5\u5bf9\u4e8e\u6b63\u6837\u672c\u800c\u8a00\uff0c\u8f93\u51fa\u6982\u7387\u8d8a\u5927\u635f\u5931\u8d8a\u5c0f\u3002\u5bf9\u4e8e\u8d1f\u6837\u672c\u800c\u8a00\uff0c\u8f93\u51fa\u6982\u7387\u8d8a\u5c0f\u5219\u635f\u5931\u8d8a\u5c0f\u3002\u6b64\u65f6\u7684\u635f\u5931\u51fd\u6570\u5728\u5927\u91cf\u7b80\u5355\u6837\u672c\u7684\u8fed\u4ee3\u8fc7\u7a0b\u4e2d\u6bd4\u8f83\u7f13\u6162\u4e14\u53ef\u80fd\u65e0\u6cd5\u4f18\u5316\u81f3\u6700\u4f18\u3002<\/p>\n
<img alt=""img"" referrerpolicy=""no-referrer"" src=""https:\/\/uploadfiles.nowcoder.com\/images\/20190315\/311436_1552657519849_21259D5A3307E27C1AD9AAC6160B05CA""><\/p>\n
<img alt=""img"" referrerpolicy=""no-referrer"" src=""https:\/\/uploadfiles.nowcoder.com\/images\/20190315\/311436_1552657505129_0D7FBDDC029A298D16708726E43FB2E7""><\/p>\n
\u9996\u5148\u5728\u539f\u6709\u7684\u57fa\u7840\u4e0a\u52a0\u4e86\u4e00\u4e2a\u56e0\u5b50\uff0c\u5176\u4e2dgamma>0\u4f7f\u5f97\u51cf\u5c11\u6613\u5206\u7c7b\u6837\u672c\u7684\u635f\u5931\u3002\u4f7f\u5f97\u66f4\u5173\u6ce8\u4e8e\u56f0\u96be\u7684\u3001\u9519\u5206\u7684\u6837\u672c\u3002<\/p>\n
\u4f8b\u5982gamma\u4e3a2\uff0c\u5bf9\u4e8e\u6b63\u7c7b\u6837\u672c\u800c\u8a00\uff0c\u9884\u6d4b\u7ed3\u679c\u4e3a0.95\u80af\u5b9a\u662f\u7b80\u5355\u6837\u672c\uff0c\u6240\u4ee5\uff081-0.95\uff09\u7684gamma\u6b21\u65b9\u5c31\u4f1a\u5f88\u5c0f\uff0c\u8fd9\u65f6\u635f\u5931\u51fd\u6570\u503c\u5c31\u53d8\u5f97\u66f4\u5c0f\u3002\u800c\u9884\u6d4b\u6982\u7387\u4e3a0.3\u7684\u6837\u672c\u5176\u635f\u5931\u76f8\u5bf9\u5f88\u5927\u3002\u5bf9\u4e8e\u8d1f\u7c7b\u6837\u672c\u800c\u8a00\u540c\u6837\uff0c\u9884\u6d4b0.1\u7684\u7ed3\u679c\u5e94\u5f53\u8fdc\u6bd4\u9884\u6d4b0.7\u7684\u6837\u672c\u635f\u5931\u503c\u8981\u5c0f\u5f97\u591a\u3002\u5bf9\u4e8e\u9884\u6d4b\u6982\u7387\u4e3a0.5\u65f6\uff0c\u635f\u5931\u53ea\u51cf\u5c11\u4e860.25\u500d\uff0c\u6240\u4ee5\u66f4\u52a0\u5173\u6ce8\u4e8e\u8fd9\u79cd\u96be\u4ee5\u533a\u5206\u7684\u6837\u672c\u3002\u8fd9\u6837\u51cf\u5c11\u4e86\u7b80\u5355\u6837\u672c\u7684\u5f71\u54cd\uff0c\u5927\u91cf\u9884\u6d4b\u6982\u7387\u5f88\u5c0f\u7684\u6837\u672c\u53e0\u52a0\u8d77\u6765\u540e\u7684\u6548\u5e94\u624d\u53ef\u80fd\u6bd4\u8f83\u6709\u6548\u3002<\/p>\n
\u6b64\u5916\uff0c\u52a0\u5165\u5e73\u8861\u56e0\u5b50alpha\uff0c\u7528\u6765\u5e73\u8861\u6b63\u8d1f\u6837\u672c\u672c\u8eab\u7684\u6bd4\u4f8b\u4e0d\u5747\uff1a<\/p>\n
<img alt=""img"" referrerpolicy=""no-referrer"" src=""https:\/\/uploadfiles.nowcoder.com\/images\/20190315\/311436_1552657490617_00DB87D29DA5A959E603CF06BC578795""><\/p>\n
\u53ea\u6dfb\u52a0alpha\u867d\u7136\u53ef\u4ee5\u5e73\u8861\u6b63\u8d1f\u6837\u672c\u7684\u91cd\u8981\u6027\uff0c\u4f46\u662f\u65e0\u6cd5\u89e3\u51b3\u7b80\u5355\u4e0e\u56f0\u96be\u6837\u672c\u7684\u95ee\u9898\u3002<\/p>\n
lambda\u8c03\u8282\u7b80\u5355\u6837\u672c\u6743\u91cd\u964d\u4f4e\u7684\u901f\u7387\uff0c\u5f53lambda\u4e3a0\u65f6\u5373\u4e3a\u4ea4\u53c9\u71b5\u635f\u5931\u51fd\u6570\uff0c\u5f53lambda\u589e\u52a0\u65f6\uff0c\u8c03\u6574\u56e0\u5b50\u7684\u5f71\u54cd\u4e5f\u5728\u589e\u52a0\u3002\u5b9e\u9a8c\u53d1\u73b0lambda\u4e3a2\u662f\u6700\u4f18\u3002<\/p>\n
<pre><code> "“`
\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"
“`” \u53c2\u8003\u56de\u7b54\uff1a Focal loss\u4e3b\u8981\u662f\u4e3a\u4e86\u89e3\u51b3one-stage\u76ee\u6807\u68c0\u6d4b\u4e2d\u6b63\u8d1f […]<\/p>\n","protected":false},"author":7,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-45053","post","type-post","status-publish","format-standard","hentry","category-c"],"_links":{"self":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/45053","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/comments?post=45053"}],"version-history":[{"count":1,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/45053\/revisions"}],"predecessor-version":[{"id":45054,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/45053\/revisions\/45054"}],"wp:attachment":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/media?parent=45053"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/categories?post=45053"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/tags?post=45053"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}