{"id":384,"date":"2018-05-31T11:31:11","date_gmt":"2018-05-31T02:31:11","guid":{"rendered":"https:\/\/mieruca-ai.com\/ai\/?p=384"},"modified":"2019-08-29T09:48:56","modified_gmt":"2019-08-29T00:48:56","slug":"viterbi_algorithm","status":"publish","type":"post","link":"https:\/\/mieruca-ai.com\/ai\/viterbi_algorithm\/","title":{"rendered":"\u3010\u6280\u8853\u89e3\u8aac\u3011HMM\u306b\u57fa\u3065\u3044\u305fViterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306b\u3088\u308b\u89e3\u63a8\u5b9a\u624b\u6cd5(\u4f8b\u984c\u3064\u304d)"},"content":{"rendered":"<p style=\"text-align: right;\">\n\u57f7\u7b46\uff1a\u91d1\u5b50\u51b4\n<\/p>\n<p>\n\u4eca\u56de\u306f\uff0c\u5f62\u614b\u7d20\u89e3\u6790\u5668\u3067\u3042\u308bMeCab\uff0cChasen\uff0cJUMAN\u3067<b>\u89e3\u63a2\u7d22\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0<\/b>\u306b\u63a1\u7528\u3055\u308c\u3066\u3044\u308b<b><span style=\"color: #ff0000;\">Viterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0(Viterbi algorithm)<\/span><\/b>\u306b\u3064\u3044\u3066\u89e3\u8aac\u3059\u308b\uff0e\n<\/p>\n<p><!--more--><\/p>\n<h3>\u76ee\u6b21<\/h3>\n<p>\n<a href=\"#toc_2\">Viterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0(Viterbi algorithm)\u3068\u306f<\/a><br \/>\n<a href=\"#toc_3\">Viterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306e\u63a8\u5b9a\u624b\u9806<\/a><br \/>\n<a href=\"#toc_4\">Viterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306e\u63a8\u5b9a\u624b\u9806(\u4f8b\u984c)<\/a><br \/>\n<a href=\"#toc_5\">Viterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306e\u5fdc\u7528\u53ef\u80fd\u6027<\/a><br \/>\n<a href=\"#toc_6\">\u53c2\u8003<\/a>\n<\/p>\n<h2 id=\"toc_2\">Viterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0(Viterbi algorithm)\u3068\u306f<\/h2>\n<p>\n\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306e\u89e3\u8aac\u306b\u3046\u3064\u308b\u524d\u306b\uff0c\u307e\u305a\u306f\u6982\u8981\u3092\u7406\u89e3\u3057\u3088\u3046\uff0e\n<\/p>\n<h3>Viterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306e\u6982\u8981<\/h3>\n<p>\n<b>&#8220;\u30d3\u30bf\u30d3\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\uff08\u82f1: Viterbi algorithm\uff09\u306f\u3001\u89b3\u6e2c\u3055\u308c\u305f\u4e8b\u8c61\u7cfb\u5217\u3092\u7d50\u679c\u3068\u3057\u3066\u751f\u3058\u308b\u96a0\u3055\u308c\u305f\u72b6\u614b\u306e\u6700\u3082\u5c24\u3082\u3089\u3057\u3044\u4e26\u3073\uff08\u30d3\u30bf\u30d3\u7d4c\u8def\u3068\u547c\u3076\uff09\u3092\u63a2\u3059\u52d5\u7684\u8a08\u753b\u6cd5\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306e\u4e00\u7a2e\u3067\u3042\u308a\u3001\u7279\u306b\u96a0\u308c\u30de\u30eb\u30b3\u30d5\u30e2\u30c7\u30eb\u306b\u57fa\u3065\u3044\u3066\u3044\u308b\u3002&#8221;<\/b> &#8211; <a href=\"https:\/\/ja.wikipedia.org\/wiki\/%E3%83%93%E3%82%BF%E3%83%93%E3%82%A2%E3%83%AB%E3%82%B4%E3%83%AA%E3%82%BA%E3%83%A0\">\u30d3\u30bf\u30d3\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0(wikipedia)<\/a>\n<\/p>\n<p>\n\u4e0a\u8a18\u306e\u6982\u8981\u3092\u898b\u308b\u306b\uff0cViterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u3092\u7406\u89e3\u3059\u308b\u305f\u3081\u306b\u306f\u4e8b\u524d\u306b<b>\u52d5\u7684\u8a08\u753b\u6cd5<\/b>\u3068<b>\u96a0\u308c\u30de\u30eb\u30b3\u30d5\u30e2\u30c7\u30eb(HMM)<\/b>\u306b\u3064\u3044\u3066\u7406\u89e3\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u305d\u3046\u3060\uff0e\u5f8c\u8005\u306e\u96a0\u308c\u30de\u30eb\u30b3\u30d5\u30e2\u30c7\u30eb\u306b\u3064\u3044\u3066\u306f\u5f53\u30d6\u30ed\u30b0\u3067\u3059\u3067\u306b\u53d6\u308a\u6271\u3063\u305f\u984c\u6750\u306e\u305f\u3081\uff0c\u305d\u3061\u3089\u3092\u3054\u89a7\u3044\u305f\u3060\u304d\u305f\u3044\uff0e<br \/>\u3000\u21d2<a href=\"https:\/\/mieruca-ai.com\/ai\/markov_model_hmm\/\">\u30de\u30eb\u30b3\u30d5\u30e2\u30c7\u30eb\u3068\u96a0\u308c\u30de\u30eb\u30b3\u30d5\u30e2\u30c7\u30eb<\/a><br \/>\n\u305d\u308c\u3067\u306f\uff0c<b>\u52d5\u7684\u8a08\u753b\u6cd5<\/b>\u306b\u3064\u3044\u3066\u78ba\u8a8d\u3057\u3066\u3044\u3053\u3046\uff0e\n<\/p>\n<h3>\u52d5\u7684\u8a08\u753b\u6cd5(Dynamic Programming)\u3068\u306f<\/h3>\n<p>\n\u300cViterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306f\u52d5\u7684\u8a08\u753b\u6cd5\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306e\u4e00\u7a2e\u300d\u3068wikipedia\u306e\u6982\u8981\u306b\u306f\u8a18\u8f09\u3057\u3066\u3042\u308b\u304c\uff0c\u305d\u3082\u305d\u3082<b>\u52d5\u7684\u8a08\u753b\u6cd5<\/b>\u3068\u306f\u4f55\u306a\u306e\u3060\u308d\u3046\u304b\uff0ewikipedia\u3092\u78ba\u8a8d\u3057\u3066\u307f\u3088\u3046\uff0e\n<\/p>\n<p>\n<b>&#8220;\u52d5\u7684\u8a08\u753b\u6cd5\uff08\u3069\u3046\u3066\u304d\u3051\u3044\u304b\u304f\u307b\u3046\u3001\u82f1: Dynamic Programming, DP\uff09\u306f\u3001\u8a08\u7b97\u6a5f\u79d1\u5b66\u306e\u5206\u91ce\u306b\u304a\u3044\u3066\u3001\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306e\u5206\u985e\u306e1\u3064\u3067\u3042\u308b\u3002\u5bfe\u8c61\u3068\u306a\u308b\u554f\u984c\u3092\u8907\u6570\u306e\u90e8\u5206\u554f\u984c\u306b\u5206\u5272\u3057\u3001\u90e8\u5206\u554f\u984c\u306e\u8a08\u7b97\u7d50\u679c\u3092\u8a18\u9332\u3057\u306a\u304c\u3089\u89e3\u3044\u3066\u3044\u304f\u624b\u6cd5\u3092\u7dcf\u79f0\u3057\u3066\u3053\u3046\u547c\u3076\u3002&#8221;<\/b> &#8211; <a href=\"https:\/\/ja.wikipedia.org\/wiki\/%E5%8B%95%E7%9A%84%E8%A8%88%E7%94%BB%E6%B3%95\">\u52d5\u7684\u8a08\u753b\u6cd5(wikipedia)<\/a>\n<\/p>\n<p>\n\u5177\u4f53\u7684\u306b\u306f\uff0c\u4ee5\u4e0b\u306e2\u6761\u4ef6\u3092\u6e80\u305f\u3059\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u3092<b><span style=\"color: #ff0000;\">\u52d5\u7684\u8a08\u753b\u6cd5<\/span><\/b>\u3068\u547c\u3076\uff0e<br \/>\n<strong>\u25c6\u5206\u5272\u7d71\u6cbb\u6cd5<\/strong><br \/>\n\u5206\u5272\u7d71\u6cbb\u6cd5\u3067\u306f\uff0c\u5927\u304d\u306a\u554f\u984c\u3092\u5c0f\u3055\u306a\u554f\u984c\u306b\u5206\u5272\u3057\uff0c\u5206\u5272\u5f8c\u306e\u5c0f\u3055\u306a\u554f\u984c\u3092\u3059\u3079\u3066\u89e3\u6c7a\u3059\u308b\u3053\u3068\u3067\u6700\u7d42\u7684\u306b\u5927\u304d\u306a\u554f\u984c\u3092\u89e3\u6c7a\u3059\u308b\uff0e\u4e00\u822c\u7684\u306b\u306f\u5c0f\u3055\u306a\u554f\u984c\u306b\u5206\u89e3\u3057\u305f\u3042\u3068\u518d\u5e30\u306b\u3088\u3063\u3066\u500b\u5225\u306b\u554f\u984c\u3092\u89e3\u6c7a\u3057\u3066\u3044\u304f\u304c\uff0c\u540c\u3058\u554f\u984c\u3092\u8907\u6570\u56de\u89e3\u6c7a\u3059\u308b\u5fc5\u8981\u304c\u3042\u308b\u5834\u5408\u306a\u3069\u306b\u8a08\u7b97\u30b3\u30b9\u30c8\u304c\u8457\u3057\u304f\u5897\u52a0\u3059\u308b\u6050\u308c\u304c\u3042\u308b\uff0e\u305d\u306e\u554f\u984c\u3092\u9632\u3050\u65b9\u6cd5\u3068\u3057\u3066\uff0c\u3082\u30461\u3064\u306e\u6761\u4ef6\u3067\u3042\u308b<b>\u30e1\u30e2\u5316<\/b>\u3092\u5229\u7528\u3059\u308b\uff0e<br \/>\n<strong>\u25c6\u30e1\u30e2\u5316<\/strong><br \/>\n\u30e1\u30e2\u5316\u3068\u306f\uff0c\u4e00\u5ea6\u8a08\u7b97\u3057\u305f\u7d50\u679c\u3092\u4fdd\u6301\u3057\u3066\u304a\u304f\u3053\u3068\u3067\u540c\u3058\u554f\u984c\u306e\u518d\u8a08\u7b97\u3092\u4e0d\u8981\u3068\u3059\u308b\u624b\u6cd5\u3067\u3042\u308b\uff0e\u30e1\u30e2\u5316\u306b\u3088\u308a\u8a08\u7b97\u91cf\u304c\u524a\u6e1b\u3055\u308c\u308b\u3053\u3068\u3067\uff0c\u30d7\u30ed\u30b0\u30e9\u30e0\u306e\u9ad8\u901f\u5316\u3084\u6700\u9069\u5316\u304c\u53ef\u80fd\u3068\u306a\u308b\uff0e\n<\/p>\n<p>\n\u52d5\u7684\u8a08\u753b\u6cd5\u306b\u3064\u3044\u3066\u306f\u5225\u306e\u8a18\u4e8b\u3067\u3088\u308a\u8a73\u7d30\u306b\u89e3\u8aac\u3059\u308b\u4e88\u5b9a\u306e\u305f\u3081\uff0c\u4eca\u56de\u306f\u4e0a\u8a18\u306e\u8aac\u660e\u306b\u3068\u3069\u3081\u308b\uff0e<br \/>\n\u6b21\u306b\uff0cViterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306e\u76ee\u7684\u306b\u3064\u3044\u3066\u78ba\u8a8d\u3057\u3088\u3046\uff0e\n<\/p>\n<h3>Viterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306e\u76ee\u7684<\/h3>\n<p>\nViterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306e\u76ee\u7684\u306f\uff0cwikipedia\u306b\u3082\u8a18\u8f09\u3055\u308c\u3066\u3044\u308b\u901a\u308a<b><span style=\"color: #ff0000;\">\u89b3\u6e2c\u3055\u308c\u305f\u51fa\u529b\u304b\u3089\u6700\u3082\u5c24\u3082\u3089\u3057\u3044\u72b6\u614b\u7cfb\u5217\u3092\u63a8\u6e2c\u3059\u308b<\/span><\/b>\u3053\u3068\u3067\u3042\u308b\uff0eViterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u3067\u306f\uff0c\u305d\u306e\u6700\u3082\u5c24\u3082\u3089\u3057\u3044\u72b6\u614b\u7cfb\u5217\u3092<b>\u30d3\u30bf\u30d3\u7d4c\u8def<\/b>\u3068\u547c\u3076\uff0e<br \/>\n\u3054\u5b58\u3058\u306e\u3068\u304a\u308a\uff0c\u96a0\u308c\u30de\u30eb\u30b3\u30d5\u30e2\u30c7\u30eb\u3067\u306f\u72b6\u614b\u304c\u96a0\u308c\u3066\u3044\u308b\uff0eViterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u3067\u306f\uff0c\u9077\u79fb\u78ba\u7387\u3068\u51fa\u529b\u78ba\u7387\uff0c\u51fa\u529b\u7d50\u679c\u304b\u3089\uff0c\u305d\u306e\u96a0\u3055\u308c\u305f\u72b6\u614b\u306e\u7cfb\u5217\u3092\u63a8\u6e2c\u3059\u308b\u3053\u3068\u304c\u76ee\u7684\u3068\u306a\u308b\uff0e\n<\/p>\n<p>\n\u305d\u308c\u3067\u306f\uff0cViterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306b\u3088\u308b\u72b6\u614b\u7cfb\u5217\u306e\u63a8\u5b9a\u624b\u9806\u3092\u78ba\u8a8d\u3057\u3088\u3046\uff0e\n<\/p>\n<h2 id=\"toc_3\">Viterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306e\u63a8\u5b9a\u624b\u9806<\/h2>\n<p>\n\u63a8\u5b9a\u624b\u9806\u3092\u78ba\u8a8d\u3059\u308b\u524d\u306b\uff0c\u3044\u304f\u3064\u304b\u5909\u6570\u3092\u5b9a\u7fa9\u3057\u3088\u3046\uff0e<br \/>\n\t\u4eca\u56de\uff0c\u63a8\u5b9a\u306b\u7528\u3044\u308b\u96a0\u308c\u30de\u30eb\u30b3\u30d5\u30e2\u30c7\u30eb\u3092<b>M<\/b>\u3068\u3057\uff0c<b>M<\/b>\u306e\u51fa\u529b\u7cfb\u5217\u3092<b>o<sup>T<\/sup><\/b>=o<sub>1<\/sub>,&#8230;,o<sub>T<\/sub>\u3068\u3059\u308b\uff0e<b>o<sup>T<\/sup><\/b>\u3092\u51fa\u529b\u3059\u308b\u3088\u3046\u306a\u72b6\u614b\u9077\u79fb\u7cfb\u5217\u306f\u8907\u6570\u3042\u308b\u3053\u3068\u304c\u4e00\u822c\u7684\u3067\u3042\u308b\u304c\uff0c\u305d\u306e\u4e2d\u304b\u3089<b><span style=\"color: #ff0000;\">\u78ba\u7387\u7684\u306b\u6700\u3082\u5c24\u3082\u3089\u3057\u3044\u72b6\u614b\u9077\u79fb\u7cfb\u5217<\/span><\/b>\u3092\u63a8\u5b9a\u3059\u308b\u3053\u3068\u304cViterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306e\u76ee\u7684\u3068\u306a\u308b\uff0e\u3053\u308c\u306f\uff0c\u72b6\u614b\u9077\u79fb\u7cfb\u5217\u3092<b>q<sup>T<\/sup><\/b>=q<sub>1<\/sub>,&#8230;,q<sub>T<\/sub>\u3068\u3057\u305f\u6642\uff0c\u51fa\u529b\u7cfb\u5217\u304c\u51fa\u529b\u3055\u308c\u308b\u78ba\u7387P(<b>o<sup>T<\/sup><\/b>,<b>q<sup>T<\/sup><\/b>|<b>M<\/b>)\u304c\u6700\u5927\u3068\u306a\u308b\u3088\u3046\u306a\u72b6\u614b\u9077\u79fb\u7cfb\u5217<b>q<sup>T<\/sup><\/b>\u3092\u6c42\u3081\u308b\u3068\u3044\u3046\u3053\u3068\u3067\u3042\u308b\uff0e<br \/>\n\t\u6642\u523bt\u3067\u72b6\u614bq<sub>i<\/sub>\u306b\u5230\u9054\u3059\u308b\u72b6\u614b\u9077\u79fb\u7cfb\u5217\u306b\u95a2\u3057\u3066\uff0c\u6700\u5927\u306e\u78ba\u7387\u5024\u3092\u03b4<sub>t<\/sub>(i)\u3068\u3059\u308b\uff0e\u3053\u306e\u3068\u304d\uff0c\u72b6\u614b\u6bce\u306b\u5b58\u5728\u3059\u308b\u03b4<sub>t<\/sub>(i)\u306f\u4ee5\u4e0b\u306e\u5f0f\u3067\u8868\u3055\u308c\u308b\uff0e\u3053\u306e\u5f0f\u306e\u53f3\u8fba\u306f<b>\u30e2\u30c7\u30ebM\u306b\u304a\u3044\u3066\uff0c<span style=\"color: #ff0000;\">\u72b6\u614bq<sub>t-1<\/sub>\u304b\u3089\u72b6\u614bq<sub>t<\/sub>\u306b\u9077\u79fb\u3057\uff0c\u304b\u3064o<sub>t<\/sub>\u304c\u51fa\u529b\u3055\u308c\u308b\u3088\u3046\u306a\u72b6\u614bq<sub>t-1<\/sub>\u306e\u4e2d\u3067\u6700\u3082\u9ad8\u3044\u78ba\u7387\u5024<\/span><\/b>\u3092\u8fd4\u3059\uff0e\u306a\u304a\uff0c\u5f0f\u4e2d\u306eX<sub>t<\/sub>\u306f\u73fe\u5728\u306e\u72b6\u614b\u3092\u8868\u3059\uff0e<\/p>\n<div class=\"show-srollbar\">$$\\delta_t (i) = \\max_{q_{t-1}} P(q_{t-1},X_t=q_i,o_t|M)$$<\/div>\n<p>\u03b4<sub>t<\/sub>(i)\u3092\u518d\u5e30\u7684\u306b\u8a08\u7b97\u3059\u308b\u305f\u3081\uff0cViterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u3067\u306f\u4ee5\u4e0b\u306e\u5f0f\u3092\u7528\u3044\u308b\uff0e\u306a\u304a\uff0c\u5f0f\u4e2d\u306ea<sub>ij<\/sub>\u306f\u72b6\u614bq<sub>i<\/sub>\u304b\u3089\u72b6\u614bq<sub>j<\/sub>\u3078\u306e\u9077\u79fb\u78ba\u7387\uff0cb<sub>j<\/sub>(o<sub>t+1<\/sub>)\u306f\u72b6\u614bq<sub>j<\/sub>\u306b\u304a\u3051\u308bo<sub>t+1<\/sub>\u306e\u51fa\u529b\u78ba\u7387\u3092\u8868\u3059\uff0e<\/p>\n<div class=\"show-srollbar\">$$\\delta_{t+1} (j) = \\max_{i} [\\delta_t(i)a_{ij}]b_j(o_{t+1})$$<\/div>\n<p>\u307e\u305f\uff0c\u6700\u5f8c\u306b\u72b6\u614b\u9077\u79fb\u7cfb\u5217\u3092\u5fa9\u5143\u3059\u308b\u305f\u3081\uff0c\u6700\u5927\u306e\u78ba\u7387\u5024\u03b4<sub>t+1<\/sub>(j)\u3092\u4e0e\u3048\u308b\u76f4\u524d\u306e\u72b6\u614b\u3092\u03c8(\uff65)\u306b\u8a18\u61b6\u3057\u3066\u304a\u304f\uff0e\n<\/p>\n<p>\u305d\u308c\u3067\u306f\uff0cViterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306e\u63a8\u5b9a\u624b\u9806\u306b\u3064\u3044\u3066\u78ba\u8a8d\u3057\u3088\u3046\uff0e\u624b\u9806\u306b\u306f\u5927\u304d\u304f\u5206\u3051\u3066\u300c\u521d\u671f\u5316\u300d\u300c\u518d\u5e30\u51e6\u7406\u300d\u300c\u518d\u5e30\u7d42\u4e86\u5f8c\u51e6\u7406\u300d\u300c\u6700\u9069\u72b6\u614b\u7cfb\u5217\u306e\u5fa9\u5143\u300d\u306e\uff14\u3064\u306e\u6bb5\u968e\u304c\u3042\u308b\uff0e\n<\/p>\n<h3>\uff11\uff0e\u521d\u671f\u5316<\/h3>\n<p>\n\u307e\u305a\uff0ct=1\u306e\u6642\u306e\u72b6\u614bq<sub>i<\/sub>(i=1,2,&#8230;,N)\u306b\u304a\u3051\u308b\u5909\u6570\u03b4\uff0c\u03c8\u306b\u3064\u3044\u3066\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u521d\u671f\u5316\u3092\u884c\u3046\uff0e\u306a\u304a\uff0c\u03c0<sub>i<\/sub>\u306f\u72b6\u614bq<sub>i<\/sub>\u306e\u521d\u671f\u72b6\u614b\u78ba\u7387(\u72b6\u614bq<sub>i<\/sub>\u304c\u521d\u671f\u72b6\u614b\u3068\u306a\u308b\u78ba\u7387)\u3067\u3042\u308b\uff0e\u3053\u306e\u3053\u3068\u304b\u3089\uff0c\u03b4<sub>1<\/sub>(i)\u306f\uff0c\u5404\u72b6\u614bq<sub>i<\/sub>\u306b\u3064\u3044\u3066<b>\u521d\u671f\u72b6\u614b\u304b\u3064o<sub>1<\/sub>\u304c\u51fa\u529b\u3055\u308c\u308b\u78ba\u7387<\/b>\u3068\u306a\u308b\u3053\u3068\u304c\u308f\u304b\u308b\u3060\u308d\u3046\uff0e<\/p>\n<div class=\"show-srollbar\">$$\\delta_1(i)=\u03c0_ib_i(o_1)$$<\/div>\n<div class=\"show-srollbar\">$$\\psi_1(i)=0$$<\/div>\n<\/p>\n<h3>\uff12\uff0e\u518d\u5e30\u51e6\u7406<\/h3>\n<p>\n\u6642\u523bt=1,&#8230;,T-1\u3068\u3057\u3066\uff0c\u72b6\u614bq<sub>j<\/sub>(j=1,&#8230;,N)\u306e\u6700\u5927\u306e\u78ba\u7387\u5024\u03b4<sub>t+1<\/sub>(j)\u3092\u518d\u5e30\u7684\u306b\u8a08\u7b97\u3059\u308b\uff0e\u307e\u305f\uff0c\u6700\u5927\u306e\u78ba\u7387\u5024\u03b4<sub>t+1<\/sub>(j)\u3092\u4e0e\u3048\u308b\u76f4\u524d\u306e\u72b6\u614bi\u3092\u8a18\u61b6\u3059\u308b\u03c8\u306b\u3064\u3044\u3066\u3082\u66f4\u65b0\u3059\u308b\uff0e<\/p>\n<div class=\"show-srollbar\">$$\\delta_{t+1} (j) = \\max_{i} [\\delta_t(i)a_{ij}]b_j(o_{t+1})$$<\/div>\n<div class=\"show-srollbar\">$$\\newcommand{\\argmax}{\\mathop{\\rm arg~max}\\limits} \\psi_{t+1} (j) = \\argmax_{i} [\\delta_t(i)a_{ij}]$$<\/div>\n<p>\u4f59\u8ac7\u3060\u304c\uff0cmax[f(x)]\u306f<b>f(x)\u3092\u6700\u5927\u306b\u3059\u308bx<\/b>\u3092\u8fd4\u3057\uff0cargmax[f(x)]\u306f<b>f(x)\u3092\u6700\u5927\u306b\u3059\u308bx\u306e<span style=\"color: #ff0000;\">\u96c6\u5408<\/span><\/b>\u3092\u8fd4\u3059\uff0e\n<\/p>\n<h3 id=\"mtoc_2\">\uff13\uff0e\u518d\u5e30\u7d42\u4e86\u5f8c\u51e6\u7406<\/h3>\n<p>\n\u518d\u5e30\u51e6\u7406\u306f\u6642\u523bt=T-1\u3067\u7d42\u4e86\u3059\u308b\u305f\u3081\uff0c\u6700\u5f8c\u306b\u6642\u523bt=T\u306b\u304a\u3051\u308b\u6700\u5927\u306e\u78ba\u7387\u5024<b>P<\/b>\u3068\u72b6\u614b\u9077\u79fb\u7cfb\u5217<b>q<sub>T<\/sub><\/b>\u3092\u8a08\u7b97\u3059\u308b\uff0e<\/p>\n<div class=\"show-srollbar\">$${\\bf P} = \\max_{i} \\delta_T (i)$$<\/div>\n<div class=\"show-srollbar\">$$\\newcommand{\\argmax}{\\mathop{\\rm arg~max}\\limits} {\\bf q_T} = \\argmax_{i} \\psi_t (i)$$<\/div>\n<\/p>\n<h3>\uff14\uff0e\u6700\u9069\u72b6\u614b\u7cfb\u5217\u306e\u5fa9\u5143<\/h3>\n<p>\n\t<a href=\"#mtoc_2\">\uff13\uff0e\u518d\u5e30\u7d42\u4e86\u5f8c\u51e6\u7406<\/a>\u307e\u3067\u306e\u624b\u9806\u3067\u5f97\u3089\u308c\u305f\u72b6\u614b\u9077\u79fb\u7cfb\u5217<b>q<sup>T<\/sup><\/b>\u306b\u3064\u3044\u3066t=T-1,&#8230;,1\u306e\u9806\u306b\u4ee5\u4e0b\u306e\u5f0f\u3092\u7528\u3044\u3066\u6700\u9069\u72b6\u614b\u7cfb\u5217\u3092\u7372\u5f97\u3059\u308b\uff0e<\/p>\n<div class=\"show-srollbar\">$${\\bf q_t} = \\psi_{t+1} ({\\bf q_{t+1}})$$<\/div>\n<\/p>\n<p>\n\u4ee5\u4e0a\u304c\uff0cViterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306e\u63a8\u5b9a\u624b\u9806\u3067\u3042\u308b\uff0e\u6570\u5f0f\u306e\u307f\u3067\u306f\u308f\u304b\u308a\u3065\u3089\u3044\u90e8\u5206\u3082\u3042\u308b\u3068\u601d\u3046\u306e\u3067\uff0c\u4f8b\u984c\u3068\u56f3\u3092\u7528\u3044\u3066\u518d\u5ea6\u624b\u9806\u3092\u78ba\u8a8d\u3057\u3066\u307f\u3088\u3046\uff0e\n<\/p>\n<h2 id=\"toc_4\">Viterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306e\u63a8\u5b9a\u624b\u9806(\u4f8b\u984c)<\/h2>\n<p>\n\u305d\u308c\u3067\u306f\uff0c<a href=\"#toc_3\">Viterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306e\u63a8\u5b9a\u624b\u9806<\/a>\u3067\u78ba\u8a8d\u3057\u305f\u624b\u9806\u3092\uff0c\u4f8b\u984c\u306b\u5f53\u3066\u306f\u3081\u3066\u518d\u5ea6\u78ba\u8a8d\u3057\u3088\u3046\uff0e<br \/>\n\u4eca\u56de\uff0c\u300cJohn has fried chicken for dinner\u300d\u3068\u3044\u3046\u82f1\u6587\u306e\u54c1\u8a5e\u60c5\u5831\u3092\u63a8\u5b9a\u3059\u308b\u554f\u984c\u3092\u8003\u3048\u308b\uff0e\u5bfe\u8c61\u306e\u82f1\u6587\u306e\u54c1\u8a5e\u7cfb\u5217(\u72b6\u614b\u9077\u79fb\u7cfb\u5217)\u306b\u306f<b>\u540d\u8a5e-\u52d5\u8a5e-\u5f62\u5bb9\u8a5e-\u540d\u8a5e-\u524d\u7f6e\u8a5e-\u540d\u8a5e(\u8a33:\u30b8\u30e7\u30f3\u306f\u5915\u98df\u306b\u30d5\u30e9\u30a4\u30c9\u30c1\u30ad\u30f3\u3092\u98df\u3079\u308b)<\/b>\u3068<b>\u540d\u8a5e-\u52d5\u8a5e-\u52d5\u8a5e-\u540d\u8a5e-\u524d\u7f6e\u8a5e-\u540d\u8a5e(\u8a33:\u30b8\u30e7\u30f3\u306f\u5915\u98df\u306e\u305f\u3081\u306b\u30c1\u30ad\u30f3\u3092\u63da\u3052\u3066\u3044\u308b)<\/b>\u306e2\u30d1\u30bf\u30fc\u30f3\u304c\u8003\u3048\u3089\u308c\u308b\uff0e\u4eca\u56de\u306f\uff0c\u4e0b\u56f3\u306e\u3088\u3046\u306a\u96a0\u308c\u30de\u30eb\u30b3\u30d5\u30e2\u30c7\u30eb\u3092\u7528\u3044\u3066\uff0c\u3069\u3061\u3089\u306e\u54c1\u8a5e\u7cfb\u5217\u304c\u5c24\u3082\u3089\u3057\u3044\u304b\u3092\u78ba\u7387\u7684\u306b\u6c42\u3081\u3066\u307f\u3088\u3046\uff0e<br \/>\n<img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/mieruca-ai.com\/ai\/wp-content\/uploads\/2018\/05\/fig01a.png\" alt=\"\" width=\"648\" height=\"602\" class=\"alignnone size-full wp-image-428\" \/>\n<\/p>\n<p>\n\u3067\u306f\uff0c\u63a8\u5b9a\u624b\u9806\u306b\u6cbf\u3063\u3066\u78ba\u8a8d\u3057\u3066\u3044\u3053\u3046\uff0e\n<\/p>\n<h3>\uff11\uff0e\u521d\u671f\u5316(\u4f8b\u984c)<\/h3>\n<p>\n\u307e\u305a\uff0c\u3059\u3079\u3066\u306e\u72b6\u614bq<sub>i<\/sub>\u306b\u3064\u3044\u3066\uff0c\u03b4<sub>1<\/sub>(i)\u3068\u03c8<sub>1<\/sub>(i)\u3092\u521d\u671f\u5316\u3059\u308b\uff0e\u4eca\u56de\u306fo<sub>1<\/sub>=&#8221;John&#8221;\u3067\u3042\u308b\uff0e<\/p>\n<div class=\"show-srollbar\">$$\\delta_1(i)=\u03c0_ib_i(o_1)$$<\/div>\n<div class=\"show-srollbar\">$$\\psi_1(i)=0$$<\/div>\n<p>\u3053\u306e\u6642\u306e\u7d4c\u8def\u56f3\u306f\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u306a\u308b\uff0e\u56f3\u4e2d\u3067[\u6587\u982d]\u304b\u3089\u72b6\u614b1\u306b\u4f38\u3073\u3066\u3044\u308b\u8d64\u7dda\u306f\uff0c<b>\u72b6\u614b\u6bce\u306e\u6700\u5927\u306e\u78ba\u7387\u5024\u3092\u3068\u308b\u7d4c\u8def<\/b>\u3092\u8868\u3057\u3066\u3044\u308b\uff0e\u306a\u304a\u4eca\u56de\u306f\u56f3\u3092\u898b\u3084\u3059\u304f\u3059\u308b\u305f\u3081\uff0c\u6700\u5927\u306e\u78ba\u7387\u5024\u304c0.0\u3067\u3042\u308b\u72b6\u614b\u3078\u306e\u30d1\u30b9\u306b\u3064\u3044\u3066\u306f\u8d64\u7dda\u3092\u8a18\u8f09\u3057\u3066\u3044\u306a\u3044\uff0e\u4f8b\u3048\u3070\uff0c\u72b6\u614b2\u3067\u306fo<sub>1<\/sub>=&#8221;John&#8221;\u306e\u51fa\u529b\u78ba\u7387\u304c0\u3067\u3042\u308b\u3053\u3068\u304b\u3089\u6700\u5927\u306e\u78ba\u7387\u5024\u306f0.0\u3068\u306a\u308b\u305f\u3081\uff0c\u30d1\u30b9\u306f\u30b0\u30ec\u30fc\u306e\u70b9\u7dda\u3068\u306a\u3063\u3066\u3044\u308b\uff0e<br \/>\n<img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/mieruca-ai.com\/ai\/wp-content\/uploads\/2018\/05\/fig02b.png\" alt=\"\" width=\"300\" height=\"144\" class=\"alignnone size-medium wp-image-449\" \/>\n<\/p>\n<h3 id=\"mtoc_1\">\uff12\uff0e\u518d\u5e30\u51e6\u7406(\u4f8b\u984c)<\/h3>\n<p>\n\u521d\u3081\u306b\uff0c\u4eca\u56de\u306e\u4f8b\u984c\u3067\u518d\u5e30\u51e6\u7406\u3092\u884c\u3063\u305f\u5f8c\u306e\u7d4c\u8def\u56f3\u3092\u8f09\u305b\u3066\u304a\u304f\uff0e\u3064\u307e\u308a\uff0c\u624b\u9806\u901a\u308a\u306b\u7d4c\u8def\u3092\u63a8\u5b9a\u3057\u305f\u5834\u5408\uff0c\u72b6\u614b\u9077\u79fb\u7cfb\u5217q<sup>T<\/sup>\u306f{1,2,3,1,4,1}=<b>\u540d\u8a5e-\u52d5\u8a5e-\u5f62\u5bb9\u8a5e-\u540d\u8a5e-\u524d\u7f6e\u8a5e-\u540d\u8a5e<\/b>\u3068\u306a\u308b\u306f\u305a\u3067\u3042\u308b\uff0e\u305d\u308c\u3067\u306f\uff0c\u624b\u9806\u306b\u6cbf\u3063\u3066\u7d4c\u8def\u56f3\u3092\u4f5c\u6210\u3057\u3066\u307f\u3088\u3046\uff0e<br \/>\n<img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/mieruca-ai.com\/ai\/wp-content\/uploads\/2018\/05\/fig07a.png\" alt=\"\" width=\"300\" height=\"143\" class=\"alignnone size-medium wp-image-448\" \/>\n<\/p>\n<p><strong>\u2460t=1(o<sub>2<\/sub>=&#8221;has&#8221;)<\/strong><\/p>\n<p>\n\u4eca\u56de\u306f\u7c21\u7565\u5316\u306e\u305f\u3081\uff0c\u6700\u5927\u306e\u78ba\u7387\u5024\u304c0.0\u3067\u3042\u308b\u72b6\u614b\u306b\u3064\u3044\u3066\u306f\u03c8<sub>t<\/sub>(j)\u3092\u4fdd\u6301\u3057\u306a\u3044\u3053\u3068\u3068\u3059\u308b\uff0e\n<\/p>\n<p>\n\u3000\u25c6j=1<br \/>\n\u3000\u3000\u51fa\u529b\u78ba\u7387b<sub>1<\/sub>(o<sub>2<\/sub>)\u304c0\u306e\u305f\u3081\uff0c\u03b4<sub>2<\/sub>(1)=0.0<br \/>\n\u3000\u25c6j=2<\/p>\n<div class=\"show-srollbar\">$$\\delta_2(2)=[\\delta_1(1)a_{12}]b_2(o_2)=0.24\u30fb0.5\u30fb0.7=0.084$$<\/div>\n<div class=\"show-srollbar\">$$\\psi_2(2) = \\{1\\}$$<\/div>\n<p>\u3000\u25c6j=3<br \/>\u3000<br \/>\n\u3000\u3000\u51fa\u529b\u78ba\u7387b<sub>3<\/sub>(o<sub>2<\/sub>)\u304c0\u306e\u305f\u3081\uff0c\u03b4<sub>2<\/sub>(3)=0.0<br \/>\n\u3000\u25c6j=4<br \/>\n\u3000\u3000\u51fa\u529b\u78ba\u7387b<sub>4<\/sub>(o<sub>2<\/sub>)\u304c0\u306e\u305f\u3081\uff0c\u03b4<sub>2<\/sub>(4)=0.0<br \/>\n<img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/mieruca-ai.com\/ai\/wp-content\/uploads\/2018\/05\/fig03a.png\" alt=\"\" width=\"1112\" height=\"532\" class=\"alignnone size-full wp-image-444\" \/>\n<\/p>\n<p><strong>\u2461t=2(o<sub>3<\/sub>=&#8221;fried&#8221;)<\/strong><\/p>\n<p>\n\u3000\u25c6j=1<br \/>\n\u3000\u3000\u51fa\u529b\u78ba\u7387b<sub>1<\/sub>(o<sub>3<\/sub>)\u304c0\u306e\u305f\u3081\uff0c\u03b4<sub>3<\/sub>(1)=0.0<br \/>\n\u3000\u25c6j=2<\/p>\n<div class=\"show-srollbar\">$$\\delta_3(2) = \\max_{i} [\\delta_2(i)a_{i2}]b_2(o_3) = [\\delta_2(2)a_{22}]b_2(o_3) = 0.084\u30fb0.3\u30fb0.3 = 0.00756$$<\/div>\n<div class=\"show-srollbar\">$$\\psi_3(2) = \\{2\\}$$<\/div>\n<p>\u3000\u25c6j=3<\/p>\n<div class=\"show-srollbar\">$$\\delta_3 (3) = \\max_{i} [\\delta_2(i)a_{i3}]b_3(o_3) = [\\delta_2(2)a_{23}]b_3(o_3) = 0.084\u30fb0.2\u30fb1.0 = 0.0168$$<\/div>\n<div class=\"show-srollbar\">$$\\psi_3 (3) = \\{2\\}$$<\/div>\n<p>\u3000\u25c6j=4<br \/>\n\u3000\u3000\u51fa\u529b\u78ba\u7387b<sub>4<\/sub>(o<sub>3<\/sub>)\u304c0\u306e\u305f\u3081\uff0c\u03b4<sub>3<\/sub>(4)=0.0<br \/>\n<img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/mieruca-ai.com\/ai\/wp-content\/uploads\/2018\/05\/fig04a.png\" alt=\"\" width=\"300\" height=\"144\" class=\"alignnone size-medium wp-image-445\" \/>\n<\/p>\n<p><strong>\u2462t=3(o<sub>4<\/sub>=&#8221;chicken&#8221;)<\/strong><\/p>\n<p>\n\u3000\u25c6j=1<\/p>\n<div class=\"show-srollbar\">$$\\delta_4(1) = \\max_{i} [\\delta_3(i)a_{i1}]b_1(o_4) = [\\delta_3(3)a_{31}]b_1(o_4) = 0.0168\u30fb0.5\u30fb0.3 = 0.00252$$<\/div>\n<div class=\"show-srollbar\">$$\\psi_4(1) = \\{3\\}$$<\/div>\n<p>\u3000\u25c6j=2<br \/>\n\u3000\u3000\u51fa\u529b\u78ba\u7387b<sub>2<\/sub>(o<sub>4<\/sub>)\u304c0\u306e\u305f\u3081\uff0c\u03b4<sub>4<\/sub>(2)=0.0<br \/>\n\u3000\u25c6j=3<br \/>\n\u3000\u3000\u51fa\u529b\u78ba\u7387b<sub>3<\/sub>(o<sub>4<\/sub>)\u304c0\u306e\u305f\u3081\uff0c\u03b4<sub>4<\/sub>(3)=0.0<br \/>\n\u3000\u25c6j=4<br \/>\n\u3000\u3000\u51fa\u529b\u78ba\u7387b<sub>4<\/sub>(o<sub>4<\/sub>)\u304c0\u306e\u305f\u3081\uff0c\u03b4<sub>4<\/sub>(4)=0.0<br \/>\n<img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/mieruca-ai.com\/ai\/wp-content\/uploads\/2018\/05\/fig05a.png\" alt=\"\" width=\"300\" height=\"144\" class=\"alignnone size-medium wp-image-446\" \/><br \/>\n\u3053\u3053\u3067\u6ce8\u76ee\u3057\u3066\u307b\u3057\u3044\u306e\u306f\uff0c\u72b6\u614bq<sub>2<\/sub>\u3067\u306f\u306a\u304f\u72b6\u614bq<sub>3<\/sub>\u304b\u3089\u306e\u30d1\u30b9\u304c\u63a1\u7528\u3055\u308c\u305f\u70b9\u3067\u3042\u308b\uff0e\u3053\u308c\u306f<b>o<sub>3<\/sub>=&#8221;fried&#8221;\u304c<span style=\"color: #ff0000;\">\u52d5\u8a5e\u3088\u308a\u3082\u5f62\u5bb9\u8a5e\u3067\u3042\u308b\u78ba\u7387\u304c\u9ad8\u3044<\/span><\/b>\u3068\u63a8\u5b9a\u3055\u308c\u305f\u3053\u3068\u3092\u8868\u3057\u3066\u3044\u308b\uff0e\n<\/p>\n<p><strong>\u2463t=4(o<sub>5<\/sub>=&#8221;for&#8221;)<\/strong><\/p>\n<p>\n\u3000\u25c6j=1<br \/>\n\u3000\u3000\u51fa\u529b\u78ba\u7387b<sub>1<\/sub>(o<sub>5<\/sub>)\u304c0\u306e\u305f\u3081\uff0c\u03b4<sub>5<\/sub>(1)=0.0<br \/>\n\u3000\u25c6j=2<br \/>\n\u3000\u3000\u51fa\u529b\u78ba\u7387b<sub>2<\/sub>(o<sub>5<\/sub>)\u304c0\u306e\u305f\u3081\uff0c\u03b4<sub>5<\/sub>(2)=0.0<br \/>\n\u3000\u25c6j=3<br \/>\n\u3000\u3000\u51fa\u529b\u78ba\u7387b<sub>3<\/sub>(o<sub>5<\/sub>)\u304c0\u306e\u305f\u3081\uff0c\u03b4<sub>5<\/sub>(3)=0.0<br \/>\n\u3000\u25c6j=4<\/p>\n<div class=\"show-srollbar\">$$\\delta_5(4) = \\max_{i} [\\delta_4(i)a_{i4}]b_4(o_5) = [\\delta_4(1)a_{14}]b_4(o_5) = 0.00252\u30fb0.2\u30fb1.0 = 0.000504$$<\/div>\n<div class=\"show-srollbar\">$$\\psi_5(4) = \\{1\\}$$<\/div>\n<p><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/mieruca-ai.com\/ai\/wp-content\/uploads\/2018\/05\/fig06a.png\" alt=\"\" width=\"300\" height=\"144\" class=\"alignnone size-medium wp-image-447\" \/>\n<\/p>\n<p><strong>\u2464t=5(o<sub>6<\/sub>=&#8221;dinner&#8221;)<\/strong><\/p>\n<p>\n\u3000\u25c6j=1<\/p>\n<div class=\"show-srollbar\">$$\\delta_6(1) = \\max_{i} [\\delta_5(i)a_{i1}]b_1(o_6) = [\\delta_5(4)a_{41}]b_1(o_6) = 0.000504\u30fb0.7\u30fb0.3 = 0.00010584$$<\/div>\n<div class=\"show-srollbar\">$$\\psi_6(1) = \\{4\\}$$<\/div>\n<p>\u3000\u25c6j=2<br \/>\n\u3000\u3000\u51fa\u529b\u78ba\u7387b<sub>2<\/sub>(o<sub>6<\/sub>)\u304c0\u306e\u305f\u3081\uff0c\u03b4<sub>6<\/sub>(2)=0.0<br \/>\n\u3000\u25c6j=3<br \/>\n\u3000\u3000\u51fa\u529b\u78ba\u7387b<sub>3<\/sub>(o<sub>6<\/sub>)\u304c0\u306e\u305f\u3081\uff0c\u03b4<sub>6<\/sub>(3)=0.0<br \/>\n\u3000\u25c6j=4<br \/>\n\u3000\u3000\u51fa\u529b\u78ba\u7387b<sub>4<\/sub>(o<sub>6<\/sub>)\u304c0\u306e\u305f\u3081\uff0c\u03b4<sub>6<\/sub>(4)=0.0<br \/>\n<img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/mieruca-ai.com\/ai\/wp-content\/uploads\/2018\/05\/fig07a.png\" alt=\"\" width=\"300\" height=\"143\" class=\"alignnone size-medium wp-image-448\" \/>\n<\/p>\n<h3>\uff13\uff0e\u518d\u5e30\u7d42\u4e86\u5f8c\u51e6\u7406(\u4f8b\u984c)<\/h3>\n<p>\n<a href=\"#mtoc_1\">\uff12\uff0e\u518d\u5e30\u51e6\u7406(\u4f8b\u984c)<\/a>\u3067t=T-1=5\u307e\u3067\u518d\u5e30\u51e6\u7406\u3092\u884c\u3063\u305f\u305f\u3081\uff0ct=T=6\u306b\u304a\u3051\u308b\u6700\u5927\u306e\u78ba\u7387\u5024<b>P<\/b>\u3068\u72b6\u614b\u7cfb\u5217<b>q<sub>T<\/sub><\/b>\u3092\u8a08\u7b97\u3059\u308b\uff0e<\/p>\n<div class=\"show-srollbar\">$${\\bf P} = \\max_{i} \\delta_T (i) = \\delta_6 (1) = 0.00010584$$<\/div>\n<div class=\"show-srollbar\">$$\\newcommand{\\argmax}{\\mathop{\\rm arg~max}\\limits} {\\bf q_6} = \\argmax_{i} \\psi_t (i) = \\psi_6 (1) = \\{1\\}$$<\/div>\n<\/p>\n<h3>\uff14\uff0e\u6700\u9069\u72b6\u614b\u7cfb\u5217\u306e\u5fa9\u5143(\u4f8b\u984c)<\/h3>\n<p>\n\u6700\u5f8c\u306b\uff0ct=6,5,4,3,2,1\u3068\u3057\u3066\u6700\u9069\u72b6\u614b\u7cfb\u5217\u3092\u30d0\u30c3\u30af\u30c8\u30e9\u30c3\u30af\u306b\u3088\u3063\u3066\u5fa9\u5143\u3059\u308b\uff0e<\/p>\n<div class=\"show-srollbar\">$${\\bf q_5} = \\psi_6 ({\\bf q_6}) = \\psi_6 (1) = 4$$<\/div>\n<div class=\"show-srollbar\">$${\\bf q_4} = \\psi_5 ({\\bf q_5}) = \\psi_5 (4) = 1$$<\/div>\n<div class=\"show-srollbar\">$${\\bf q_3} = \\psi_4 ({\\bf q_4}) = \\psi_4 (1) = 3$$<\/div>\n<div class=\"show-srollbar\">$${\\bf q_2} = \\psi_3 ({\\bf q_3}) = \\psi_3 (3) = 2$$<\/div>\n<div class=\"show-srollbar\">$${\\bf q_1} = \\psi_2 ({\\bf q_2}) = \\psi_2 (2) = 1$$<\/div>\n<\/p>\n<p>\n\u3088\u3063\u3066\uff0c\u6700\u9069\u72b6\u614b\u7cfb\u5217<b>q<sup>T<\/sup><\/b>(t=1,2,3,4,5,6)\u306f\u4ee5\u4e0b\u306e\u901a\u308a\u3068\u306a\u308b\uff0e<\/p>\n<div class=\"show-srollbar\">$${\\bf q^T} = \\{q_t|t=1,2,3,4,5,6\\} = \\{1,2,3,1,4,1\\}$$<\/div>\n<p>\u3053\u306e\u7d50\u679c\u306f\uff0c\u4eca\u56de\u306e\u96a0\u308c\u30de\u30eb\u30b3\u30d5\u30e2\u30c7\u30eb\u3067\u63a8\u5b9a\u3057\u305f\u7d50\u679c\uff0c<b>\u54c1\u8a5e\u7cfb\u5217<span style=\"color: #ff0000;\">\u540d\u8a5e-\u52d5\u8a5e-\u5f62\u5bb9\u8a5e-\u540d\u8a5e-\u524d\u7f6e\u8a5e-\u540d\u8a5e(\u8a33:\u30b8\u30e7\u30f3\u306f\u5915\u98df\u306b\u30d5\u30e9\u30a4\u30c9\u30c1\u30ad\u30f3\u3092\u98df\u3079\u308b)\u306e\u65b9\u304c\u5c24\u3082\u3089\u3057\u3044<\/span>\u3068\u63a8\u5b9a\u3055\u308c\u305f<\/b>\u3053\u3068\u3092\u8868\u3057\u3066\u3044\u308b\uff0e\u3082\u3061\u308d\u3093\uff0c\u5225\u306e\u96a0\u308c\u30de\u30eb\u30b3\u30d5\u30e2\u30c7\u30eb\u3092\u7528\u3044\u3066\u63a8\u5b9a\u3057\u305f\u5834\u5408\u306b\u7d50\u679c\u304c\u5909\u308f\u308b\u3053\u3068\u3082\u3042\u308b\uff0e\u3053\u3053\u3067\u91cd\u8981\u3068\u306a\u308b\u306e\u306f<b>\u96a0\u308c\u30de\u30eb\u30b3\u30d5\u30e2\u30c7\u30eb\u306e\u30d1\u30e9\u30e1\u30fc\u30bf(\u9077\u79fb\u78ba\u7387\uff0c\u51fa\u529b\u78ba\u7387)<\/b>\u3067\u3042\u308b\u304c\uff0c\u305d\u308c\u3089\u306e\u6c7a\u5b9a\u306b\u306f<b>\u51fa\u529b\u7cfb\u5217\u304b\u3089\u30e2\u30c7\u30eb\u306e\u30d1\u30e9\u30e1\u30fc\u30bf\u3092\u63a8\u5b9a\u3059\u308b<span style=\"color: #ff0000;\">\u30d0\u30a6\u30e0\u30fb\u30a6\u30a7\u30eb\u30c1\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0<\/span><\/b>\u304c\u7528\u3044\u3089\u308c\u308b(\u8aac\u660e\u306f\u5272\u611b)\uff0e\n<\/p>\n<p>\n\u4ee5\u4e0a\u3067\uff0cViterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306b\u3088\u308b\u63a8\u5b9a\u306e\u624b\u9806\u306e\u89e3\u8aac\u306f\u7d42\u4e86\u3067\u3042\u308b\uff0e\u6700\u5f8c\u306b\uff0cViterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306e\u5fdc\u7528\u53ef\u80fd\u6027\u306b\u3064\u3044\u3066\u78ba\u8a8d\u3057\u3088\u3046\uff0e\n<\/p>\n<h2 id=\"toc_5\">Viterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306e\u5fdc\u7528\u53ef\u80fd\u6027<\/h2>\n<p>\nViterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306f\u3069\u306e\u3088\u3046\u306a\u5206\u91ce\u3067\u5fdc\u7528\u3067\u304d\u308b\u306e\u3067\u3042\u308d\u3046\u304b\uff0e\u5fdc\u7528\u5206\u91ce\u306e\u3072\u3068\u3064\u306b<b>\u81ea\u7136\u8a00\u8a9e\u51e6\u7406\u5206\u91ce<\/b>\u304c\u6319\u3052\u3089\u308c\u308b\uff0e\u672c\u89e3\u8aac\u306e\u5c0e\u5165\u3067\u3082\u8ff0\u3079\u305f\u901a\u308a\uff0cViterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306f\u5f62\u614b\u7d20\u89e3\u6790\u5668\u3067\u3042\u308bMeCab\uff0cChasen\uff0cJUMAN\u3067<b>\u89e3\u63a2\u7d22\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0<\/b>\u3068\u3057\u3066\u63a1\u7528\u3055\u308c\u3066\u3044\u308b\uff0e\u8907\u6570\u306e\u89e3\u91c8\u304c\u3042\u308a\u5f97\u308b\u81ea\u7136\u8a00\u8a9e\u3092\u5f62\u614b\u7d20\u3054\u3068\u306b\u5206\u89e3\u3057\u54c1\u8a5e\u60c5\u5831\u3092\u4ed8\u52a0\u3059\u308b\u5834\u5408\uff0c\u8907\u6570\u306e\u5206\u89e3\u30d1\u30bf\u30fc\u30f3\u3092\u78ba\u7387\u7684\u306b\u6bd4\u8f03\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u308b\uff0e<br \/>\u305d\u306e\u4ed6\u306b\u3082\uff0c<b>\u97f3\u58f0\u51e6\u7406\u5206\u91ce<\/b>\u3084<b>\u6587\u5b57\u8a8d\u8b58\u5206\u91ce<\/b>\u3067\u3082Viterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306b\u3088\u308b\u63a8\u5b9a\u306f\u5927\u3044\u306b\u8ca2\u732e\u3057\u3066\u3044\u308b\uff0e\n<\/p>\n<h2 id=\"toc_6\">\u53c2\u8003<\/h2>\n<p>\u3010\u8ad6\u6587\u3011<br \/>\n\u30fb<a href=\"http:\/\/www.fabiomontoro.com.br\/wp-content\/uploads\/2016\/08\/1967-04-Viterbi-Error_Bounds_for_Convolutional_Codes_and.pdf\">Error Bounds for Convolutional Codes and an Asymptotically Optimum Decoding Algorithm<\/a><br \/>\n\u30fb<a href=\"https:\/\/pdfs.semanticscholar.org\/3832\/3133f8421f1c299890259eeb359fbdaaa757.pdf\">The Viterbi Algorithm<\/a><br \/>\n\u3010\u66f8\u7c4d\u3011<br \/>\n\u30fb\u5317 \u7814\u4e8c:\u8a00\u8a9e\u3068\u8a08\u7b97\u30fc\uff14\u3000\u78ba\u7387\u7684\u8a00\u8a9e\u30e2\u30c7\u30eb(1999)\uff0e<\/p>\n<p>\u3010Web\u30b5\u30a4\u30c8\u3011<br \/>\n\u30fb<a href=\"https:\/\/ja.wikipedia.org\/wiki\/%E3%83%93%E3%82%BF%E3%83%93%E3%82%A2%E3%83%AB%E3%82%B4%E3%83%AA%E3%82%BA%E3%83%A0\">\u30d3\u30bf\u30d3\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0 &#8211; wikipedia<\/a><br \/>\n\u30fb<a href=\"https:\/\/ja.wikipedia.org\/wiki\/%E5%8B%95%E7%9A%84%E8%A8%88%E7%94%BB%E6%B3%95\">\u52d5\u7684\u8a08\u753b\u6cd5 &#8211; wikipedia<\/a><br \/>\n\u30fb<a href=\"https:\/\/ja.wikipedia.org\/wiki\/%E5%88%86%E5%89%B2%E7%B5%B1%E6%B2%BB%E6%B3%95\">\u5206\u5272\u7d71\u6cbb\u6cd5 &#8211; wikipedia<\/a><br \/>\n\u30fb<a href=\"https:\/\/ja.wikipedia.org\/wiki\/%E3%83%A1%E3%83%A2%E5%8C%96\">\u30e1\u30e2\u5316 &#8211; wikipedia<\/a><br \/>\n\u30fb<a href=\"https:\/\/spjai.com\/viterbi-algorithm\/\">\u30d3\u30bf\u30d3\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u3010\u5165\u9580\u3011\u5177\u4f53\u4f8b\u3067\u5206\u304b\u308a\u3084\u3059\u304f\u89e3\u8aac\uff01\uff08Viterbi\uff09<\/a><br \/>\n\u30fb<a href=\"http:\/\/kento1109.hatenablog.com\/entry\/2017\/12\/15\/160315\">\u96a0\u308c\u30de\u30eb\u30b3\u30d5\u30e2\u30c7\u30eb\uff08HMM\uff09\u306b\u3064\u3044\u3066<\/a><br \/>\n\u30fb<a href=\"https:\/\/www.slideshare.net\/KojiSekiguchi\/hmm-viterbi-14411723\">HMM viterbi<\/a><br \/>\n\u30fb<a href=\"http:\/\/www.tsc.ac.jp\/tagblocks\/lang\/news\/Press\/0000000548.html\">2009 Open Campus No.3 \u8a00\u30b3\u30df\u5831\u544a\uff1c\u4f53\u9a13\u6388\u696dx3\uff1e\uff01(8\/2)<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u57f7\u7b46\uff1a\u91d1\u5b50\u51b4 \u4eca\u56de\u306f\uff0c\u5f62\u614b\u7d20\u89e3\u6790\u5668\u3067\u3042\u308bMeCab\uff0cChasen\uff0cJUMAN\u3067\u89e3\u63a2\u7d22\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306b\u63a1\u7528\u3055\u308c\u3066\u3044\u308bViterbi\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0(Viterbi algorithm)\u306b\u3064\u3044\u3066\u89e3\u8aac\u3059\u308b\uff0e<\/p>\n","protected":false},"author":1,"featured_media":575,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[4,5],"tags":[],"_links":{"self":[{"href":"https:\/\/mieruca-ai.com\/ai\/wp-json\/wp\/v2\/posts\/384"}],"collection":[{"href":"https:\/\/mieruca-ai.com\/ai\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mieruca-ai.com\/ai\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mieruca-ai.com\/ai\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mieruca-ai.com\/ai\/wp-json\/wp\/v2\/comments?post=384"}],"version-history":[{"count":23,"href":"https:\/\/mieruca-ai.com\/ai\/wp-json\/wp\/v2\/posts\/384\/revisions"}],"predecessor-version":[{"id":1065,"href":"https:\/\/mieruca-ai.com\/ai\/wp-json\/wp\/v2\/posts\/384\/revisions\/1065"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/mieruca-ai.com\/ai\/wp-json\/wp\/v2\/media\/575"}],"wp:attachment":[{"href":"https:\/\/mieruca-ai.com\/ai\/wp-json\/wp\/v2\/media?parent=384"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mieruca-ai.com\/ai\/wp-json\/wp\/v2\/categories?post=384"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mieruca-ai.com\/ai\/wp-json\/wp\/v2\/tags?post=384"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}