{"id":1999,"date":"2019-10-01T01:22:32","date_gmt":"2019-09-30T16:22:32","guid":{"rendered":"http:\/\/141.164.34.82\/?p=1999"},"modified":"2019-10-01T01:45:07","modified_gmt":"2019-09-30T16:45:07","slug":"%eb%9e%91%ea%b7%b8%eb%9e%91%ec%a3%bc-%ec%8a%b9%ec%88%98%eb%b2%95","status":"publish","type":"post","link":"http:\/\/ds.sumeun.org\/?p=1999","title":{"rendered":"\ub791\uadf8\ub791\uc8fc \uc2b9\uc218\ubc95"},"content":{"rendered":"

PRML(Pattern Recognition and Machine Learning)\uc774\ub780 \ucc45\uc774 \uc788\ub2e4. Christopher M. Bishop\uc774 \uc4f4 \uc774 \ucc45\uc740 ML\uc758 \ubc14\uc774\ube14\uc774\ub77c\uace0 \uc77c\uceeb\ub294\ub2e4. \ub300\ud559\uc6d0\uc5d0 \uc788\uc744 \ub54c\uc5d0\ub3c4 \ub204\uad70\uac00 \uc9c8\ubb38\uc744 \ud560 \ub54c\uc5d0\uba74,<\/p>\n

“\uadf8\uac70 PRML\uc5d0 \uc788\uc5b4!"\ub77c\uace0 \ub300\ub2f5\ud558\uae30\ub3c4 \ud588\ub2e4\ub294…<\/p>\n

\ud558\uc9c0\ub9c8 \ub098\ub294 \uadf8\ub2e4\uc9c0 \uc88b\uc544\ud558\uc9c0 \uc54a\uc558\ub2e4. \uc9c0\uae08 \ubd10\ub3c4 '\uc815\ub9ac\ub294 \uc798 \ud588\ub124<\/strong>'\ub77c\ub294 \ud3c9\uac00\ub97c \ub0b4\ub9b4 \uc21c \uc788\ub2e4. \ud558\uc9c0\ub9cc \ucd08\uc2ec\uc790\uc5d0\uac8c \uc88b\uc740 \uc811\uadfc \ubc29\ubc95\uc774\ub0d0? \uc774\ud574\ud558\uae30 \uc27d\ub0d0?\ub77c\uace0 \ubb3c\uc5c8\uc744 \ub54c\ub294 \uc8fc\uc800\ud560 \uc218 \ubc16\uc5d0 \uc5c6\ub2e4.[1]<\/sup><\/p>\n

[1]:<\/sup> \uc0ac\uc2e4 \uc774\ub7f0 \ubb38\uc81c\ub294 \ub9ce\uc740 \uad50\uc591<\/strong> \uc218\ud559\ucc45\uc5d0\uc11c\ub3c4 \ubc1c\uacac\ud560 \uc218 \uc788\ub2e4. \uc815\ub9ac<\/strong>\ub294 \uc798 \ud588\ub124. \uadfc\ub370 \ucd08\uc2ec\uc790\uac00 \uc774\uac78 \uc77d\uace0 \uc774\ud574\ud560 \uc218 \uc788\uaca0\uc5b4?<\/strong><\/p>\n

\ub77c\uadf8\ub791\uc950 \uc2b9\uc218\ubc95<\/h2>\n

\uc774 \ucc45\uc758 \ubd80\ub85d E\uc5d0 Lagrange Mulipliers\uac00 \ub098\uc628\ub2e4. \uc6b0\ub9ac\ub9d0\ub85c\ub294 \ub77c\uadf8\ub791\uc950 \uc2b9\uc218\ubc95<\/strong>. \ubc1c\uc74c\ud560 \ub54c\uc5d0\ub294 \ud504\ub791\uc2a4 \uc0ac\ub78c\uc778 \ub77c\uadf8\ub791\uc950<\/strong>\ub97c \uc874\uc911\ud55c\ub2e4\ub294 \uc758\ubbf8\uc5d0\uc11c \uc950<\/strong>\ub97c \uc57d\uac04 '\ud504\ub791\uc2a4\uc2dd'\uc73c\ub85c \ubc1c\uc74c\ud574\uc57c \ud55c\ub2e4.<\/p>\n

\ubd80\ub85d E\uc758 \ub0b4\uc6a9\uc774 \ud2c0\ub9b0 \ub0b4\uc6a9\uc740 \uc5c6\uc9c0\ub9cc, '\uc774\ud574\ud558\uae30 \uc27d\ub0d0?' \uadf8\uac74 \ub2e4\uc18c \ud68c\uc758\uc801\uc774\ub2e4.<\/p>\n

\ub4e4\uc5b4\uac00\uae30<\/h3>\n

\ub77c\uadf8\ub791\uc950 \uc2b9\uc218\ubc95\uc740 \uc5b4\ub5a4 \uc81c\uc57d\ud558\uc758 \ucd5c\uc801\ud654\ub97c \ub2e4\ub8ec\ub2e4.<\/p>\n

\uc608\ub97c \ub4e4\uc5b4, \\(g(\\vec{x})=0\\) \uc77c \ub54c, \\(f(\\vec{x})\\) \ub97c \ucd5c\ub300 \ub610\ub294 \ucd5c\uc18c\ud654\ud558\ub294 \uac83\uc774\ub2e4. ( \\(f(\\vec{x})\\) \ub97c \uad6c\ud558\uac70\ub098, \\(f(\\vec{x})\\) \ub97c \ucd5c\ub300\/\ucd5c\uc18c\ud654\ud558\ub294 \\(\\vec{x}\\) \ub97c \uad6c\ud55c\ub2e4.)<\/p>\n

\ud568\uc218 \\(f(\\vec{x})\\) \ub610\ub294 \\(g(\\vec{x})\\) \uc758 \uad6c\uccb4\uc801\uc778 \uc608\ub97c \uc0dd\uac01\ud574\ubcf4\uc790. <\/p>\n

\\(f(\\vec{x}) = x_1^2+x_2^2\\) ( \\(\\vec{x} = (x_1, x_2)\\) )\ub77c\uace0 \ud560\ub54c, \\(f(\\vec{x})\\) \uc758 \ucd5c\uc18c\uac12\uc740 \\(0\\) \uc774\uace0, \\(\\vec{x}=(x_1, x_2)=(0,0)\\) \uc5d0\uc11c \ucd5c\uc18c\uac12\uc744 \uc5bb\uc744 \uc218 \uc788\ub2e4.<\/p>\n

\ud558\uc9c0\ub9cc \\(x_1 + x_1 x_2 + 1= 0\\) \uc774\ub77c\ub294 \uc81c\uc57d \uc870\uac74\uc744 \uc900\ub2e4\uba74, \\(\\vec{x}=(0,0)\\) \uc740 \ud574\uac00 \ub420 \uc218 \uc5c6\ub2e4. \uc65c\ub0d0\ud558\uba74 \\(x_1=0, x_2=0\\) \uc5d0\uc11c \\(x_1 + x_1 x_2 + 1=0\\) \uc744 \ub9cc\uc871\ud558\uc9c0 \uc54a\uae30 \ub54c\ubb38\uc774\ub2e4.<\/p>\n

\ub2e4\uc2dc \ub9d0\ud574, \uc9c8\ubb38\uc740 \\(x_1 + x_1 x_2 + 1=0\\) \uc77c\ub54c, \\(x_1^2+x_2^2\\) \uc744 \ucd5c\uc18c\/\ucd5c\ub300\ud654\ud558\uac70\ub098, \ucd5c\uc18c\/\ucd5c\ub300\ud654\ud558\ub294 \\((x_1, x_2)\\) \uc744 \uad6c\ud558\ub294 \uac83\uc774\ub2e4.<\/p>\n

\uc774 \uad6c\uccb4\uc801\uc778 \uc0c1\ud669\uc5d0 \ub300\ud574 \ud55c \ubc88 \uc0b4\ud3b4\ubcf4\uace0, \ub2e4\uc2dc \uc77c\ubc18\uc801\uc778 \ud568\uc218 \\(f\\), \\(g\\) \uc5d0 \ub300\ud574 \uc598\uae30\ud574\ubcf4\uc790.<\/p>\n

minimize \\(f(x_1, x_2) = x_1^2+x_2^2\\)<\/h3>\n

\uba3c\uc800 \uc81c\uc57d \uc870\uac74 \uc5c6\uc774 \\(f(x_1, x_2) = x_1^2+x_2^2\\) \uc744 \ucd5c\uc18c\ud654\ud558\ub294 \\(\\vec{x}=(x_1, x_2)\\) \ub97c \uad6c\ud558\ub294 \ubc95\uc744 \uc0dd\uac01\ud574\ubcf4\uc790. \uac00\uc7a5 \uc190\uc26c\uc6b4 \ubc29\ubc95\uc740 \\(\\nabla f = 0\\) \uc744 \ub9cc\uc871\ud558\ub294 \\((x_1, x_2)\\) \ub97c \uad6c\ud558\ub294 \uac83\uc774\ub2e4.<\/p>\n

\uc5ec\uae30\uc11c \\(\\nabla f = (\\frac{\\partial f}{\\partial x_1}, \\frac{\\partial f}{\\partial x_2})\\) \uc774\ubbc0\ub85c \\(f(x_1, x_2) = x_1^2+x_2^2\\) \uc5d0 \ub300\ud574 \\(\\nabla f = (\\frac{\\partial f}{\\partial x_1}, \\frac{\\partial f}{\\partial x_2})=(2x_1, 2x_2)\\) \uc774\ubbc0\ub85c \\((2x_1, 2x_2) = (0,0)\\) \uc744 \ub9cc\uc871\ud558\uae30 \uc704\ud574\uc11c\ub294 \\((x_1, x_2) = (0,0)\\) \uc774\uc5b4\uc57c \ud55c\ub2e4.<\/p>\n

\\(x_1=0, x_2=0\\) \uc77c \ub54c, \\(f(x_1, x_2)\\) \ub294 \\(0\\) \uc744 \ucd5c\uc18c\uac12\uc73c\ub85c \uac16\ub294\ub2e4. <\/p>\n

minimize \\(f(x_1, x_2) = x_1^2+x_2^2\\) s.t. \\(x_1 + x_1x_2 + 1=0\\)<\/h3>\n

\ubcf4\ud1b5 $x_1 + x_1x_2+ 1=0$\uc744 \ub9cc\uc871\ud558\uba74\uc11c \\(f(x_1, x_2) = x_1^2+x_2^2\\) \uc758 \ucd5c\uc18c\uac12\uc744 \uad6c\ud558\ub294 \uac83\uc744 \ub2e4\uc74c\uacfc \uac19\uc774 \ud45c\uae30\ud558\uae30\ub3c4 \ud55c\ub2e4.<\/p>\n

minimize<\/code> \\(f(x_1, x_2) = x_1^2+x_2^2\\) s.t.<\/code> \\(x_1 + x_1x_2 + 1=0\\)<\/p>\n

\uc5ec\uae30\uc11c s<\/strong>.t<\/strong>.\ub294 s<\/strong>uch t<\/strong>hat\uc758 \uc57d\uc790\uc774\ub2e4.<\/p>\n

\uc5b4\uca0b\ub4e0, \\(f(x_1, x_2)\\) \uc758 \ucd5c\ub300\uac12 \ub610\ub294 \uadf8 \ub54c\uc758 \\((x_1, x_2)\\) \ub294 \uc5b4\ub5bb\uac8c \uad6c\ud560 \uc218 \uc788\uc744\uae4c?<\/p>\n

\ub2e4\uc74c\uc758 \ub17c\ub9ac\ub97c \ub530\ub77c\uac00 \ubcf4\uc790.<\/p>\n

\ub9cc\uc57d \\(x_1+x_1x_2+1=0\\) \uc774\ub77c\ub294 \uc81c\uc57d \uc870\uac74\uc774 \uc5c6\ub2e4\uba74 \\(f(\\vec{x})\\) \uc758 \ucd5c\ub300\/\ucd5c\uc18c\ub294 \\(\\nabla f = \\vec{0}\\) \uc5d0\uc11c \uc5bb\uc5b4\uc9c4\ub2e4. (\uc5ec\uae30\uc11c \\(\\vec{0}\\) \uc740 \uc785\ub825 \ubcc0\uc218\uc758 \uac2f\uc218 \uae38\uc774\uc758 \\(0\\) \ubca1\ud130\uc774\ub2e4.)<\/p>\n

\ud558\uc9c0\ub9cc \\(\\nabla f=(2x_1, 2x_2) = (0,0)\\) \uc5d0\uc11c \\(x_1+x_1x_2+1=0\\) \uc774 \ub9cc\uc871\ub418\uc9c0 \uc54a\ub294\ub2e4. \\((x_1, x_2)=(0,0)\\) \uc5d0\uc11c \\(x_1+x_1x_2+1\\) \uc744 \uad6c\ud574 \ubcf4\uba74 \\(0+0+1=1\\) \uc774 \ub41c\ub2e4.<\/p>\n

\uadf8\ub807\ub2e4\uba74 \ubc18\ub300\ub85c \\(x_1+x_1x_2+1=0\\) \uc77c \ub54c $\\nabla f$\ub294 \uc5b4\ub5a4 \uac12\uc744 \uac00\uc9c0\uac8c \ub420\uae4c?<\/p>\n

\ud639\uc740 \\(x_1+x_1x_2+1=0\\) \uc744 \ub9cc\uc871\ud558\uba74\uc11c \\(f(\\vec{x})\\) \ub97c \ucd5c\ub300\ud654\ud558\ub824\uba74 \\(\\nabla f\\) \ub294 \uc5b4\ub5a4 \uc870\uac74\uc744 \ub9cc\uc871\uc2dc\ucf1c\uc57c \ud558\ub294\uac00?<\/p>\n

\\(\\nabla f(\\vec{x})=\\vec{0}\\)<\/h4>\n

\ub2e4\uc2dc \uc81c\uc57d\uc870\uac74\uc774 \uc5c6\uc744 \ub54c, \\(\\nabla f(\\vec{x})=\\vec{0}\\) \uc758 \uc870\uac74\uc744 \uc0dd\uac01\ud574\ubcf4\uc790. \uc774 \uc870\uac74\uc744 \ub9cc\uc871\uc2dc\ud0a4\ub294 \uc810 \\(\\vec{x}\\) \uc5d0\uc11c \\(f\\) \uac00 \ucd5c\ub300 \ud639\uc740 \ucd5c\uc18c\uc778 \uac83\uc740 \ub2e4\uc74c\uc758 \uc2dd\uc5d0 \uc720\ucd94 \uac00\ub2a5\ud558\ub2e4.<\/p>\n

\\[ f(\\vec{x} + \\vec{\\epsilon}) \\approx f(\\vec{x}) + \\nabla f(\\vec{x}) \\cdot \\vec{\\epsilon}\\]<\/p>\n

\\(\\nabla f(\\vec{x})\\) \ub294 \uc810 \\(\\vec{x}\\) \uc5d0\uc11c \\(f(\\vec{x})\\) \uc758 \uad6d\uc18c\uc801\uc778 \ud568\uc218\uac12\uc744 \uc77c\ucc28\ud568\uc218\ub85c \uadfc\uc0ac\ud55c \uac83\uc774\ub77c \uc0dd\uac01\ud560 \uc218 \uc788\ub2e4. \ub9cc\uc57d \\(f(\\vec{x})\\) \uac00 \uc8fc\uc704\uc758 \ubaa8\ub4e0 \uac12\ubcf4\ub2e4 \ud06c\ub2e4\uba74 \\(f(\\vec{x})\\) \ub294 \ucd5c\uc18c\/\ucd5c\ub300\uac12\uc774 \ub420 \uac00\ub2a5\uc131\uc774 \uc788\ub2e4. <\/p>\n

\ub9cc\uc57d \\(\\vec{\\epsilon}\\) \uc758 \ud06c\uae30\uac00 \ub9e4\uc6b0 \uc791\ub2e4\uba74, \\(\\vec{\\epsilon}\\) \uc758 \ubc29\ud5a5\uc5d0 \uc0c1\uad00 \uc5c6\uc774<\/strong>, \uc704\uc758 \uc2dd\uc774 \uc131\ub9bd\ud55c\ub2e4. \uc5ec\uae30\uc11c \\(\\nabla f(\\vec{x})\\) \uc740 \\(\\vec{x}\\) \uc640 \uac19\uc740 \ucc28\uc6d0\uc758 \ubca1\ud130\uc774\ub2e4. \ub9cc\uc57d \\(\\nabla f(\\vec{x})\\) \uc774 \\(\\vec{0}\\) \uc774 \uc544\ub2c8\ub77c\uace0 \uc0dd\uac01\ud574\ubcf4\uc790. \\(\\nabla f(\\vec{x}) \\cdot \\vec{\\epsilon}\\) \uc774 \uc591\uc218\ub77c\uba74, \\(\\nabla f(\\vec{x}) \\cdot (-\\vec{\\epsilon})\\) \ub294 \uc74c\uc218\uc774\ubbc0\ub85c, \\(f(\\vec{x})\\) \uc740 \ucd5c\uc18c\uac12\uc774\ub098 \ucd5c\ub300\uac12\uc774 \ub420 \uc218 \uc5c6\ub2e4. (\uc65c\ub0d0\ud558\uba74 \\(f(\\vec{x}+\\vec{\\epsilon})\\) \uc740 \\(f(\\vec{x})\\) \ubcf4\ub2e4 \ud06c\uac70\ub098, \uc791\uae30 \ub54c\ubb38\uc774\ub2e4.)<\/p>\n

\ub530\ub77c\uc11c \\(f(\\vec{x} + \\vec{\\epsilon}) \\approx f(\\vec{x}) + \\nabla f(\\vec{x}) \\cdot \\vec{\\epsilon}\\) \uc5d0\uc11c \ubaa8\ub4e0 \ubc29\ud5a5\uc758 \\(\\epsilon\\) \uc5d0 \ub300\ud574 \\(f(\\vec{x}) = f(\\vec{x}+\\vec{\\epsilon}) = f(\\vec{x}) + \\nabla f(\\vec{x}) \\cdot \\vec{\\epsilon}\\) \uc774 \uc131\ub9bd\ud558\uae30 \uc704\ud574\uc11c\ub294 \\(\\nabla f(\\vec{x})=0\\) \uc774\uc5b4\uc57c \ud55c\ub2e4.[2]<\/sup><\/p>\n

[2]:<\/sup> \uace0\ub4f1\ud559\uad50\uc5d0\uc11c \\(ax=0\\) \uc774 \uc5b4\ub5a4 \\(x\\) \uc5d0 \ub300\ud574\uc11c\ub3c4 \uc131\ub9bd\ud558\ub824\uba74 \\(a=0\\) \uc774\uc5b4\uc57c \ud55c\ub2e4\uace0 \ubc30\uc6b0\uc9c0 \uc54a\uc558\ub294\uac00? <\/p>\n

( \uad6d\uc18c\uc801<\/strong>\uc73c\ub85c \\(f(\\vec{x})\\) \uac00 \ubcc0\ud558\uc9c0 \uc54a\ub294\ub2e4\ub294 \uad6d\uc18c\uc801\uc73c\ub85c<\/strong> \\(f(\\vec{x})\\) \uac00 \uc0c1\uc218 \ud568\uc218\uc784\uc744 \ub098\ud0c0\ub0b8\ub2e4. \uadf8\ub807\uae30 \ub54c\ubb38\uc5d0 \uc774 \uac12\uc774 \uacfc\uc5f0 \ucd5c\ub300\uac12<\/strong>\uc778\uc9c0, \ucd5c\uc18c\uac12<\/strong>\uc778\uc9c0, \ud639\uc740 \\(\\vec{x}\\) \uac00 saddle-point\uc778\uc9c0 \ud655\uc778\ud560 \uc218 \uc5c6\ub2e4. \ub2e4\uc2dc \ub9d0\ud574 \\(\\nabla f(\\vec{x}) =0\\) \uc740 \\(f(\\vec{x})\\) \uac00 \ucd5c\ub300 \ud639\uc740 \ucd5c\uc18c\uac12\uc774\uae30 \uc704\ud55c \ud544\uc694\uc870\uac74\uc774\ub2e4.)<\/p>\n

\\(g(\\vec{x})=0\\)<\/h4>\n

\uc774\uc81c \\(g(\\vec{x})=0\\) \uc744 \uc0dd\uac01\ud574\ubcf4\uc790. \ud568\uc218 \\(g\\) \uc5d0 \ub300\ud574\uc11c\ub3c4 \ub2e4\uc74c\uacfc \uac19\uc774 \uc4f8 \uc218 \uc788\ub2e4.<\/p>\n

\\[ g(\\vec{x} + \\vec{\\epsilon}) \\approx g(\\vec{x}) + \\nabla g(\\vec{x}) \\cdot \\vec{\\epsilon}\\]<\/p>\n

\uadf8\ub9ac\uace0 \\(g(\\vec{x})=0\\) \uc744 \ub9cc\uc871\ud558\ub294 \\(\\vec{x}\\) \uc740 \uc804\uccb4 \uc785\ub825 \uacf5\uac04\uc5d0\uc11c \uadf9\ud788 \uc77c\ubd80\ubd84\uc784\uc744 \uae30\uc5b5\ud558\uc790.<\/p>\n

\uc608\ub97c \ub4e4\uc5b4 \uc81c\uc57d\uc2dd \\(x_1+x_1x_2 + 1=0\\) \uc5d0\uc11c \\((x_1, x_2)=(-1,0)\\) \uc740 \uc81c\uc57d\uc2dd\uc744 \ub9cc\uc871\ud55c\ub2e4. \ud558\uc9c0\ub9cc \\(\\vec{\\epsilon}=(0.1, 0.1)\\) \ub85c \ud588\uc744 \ub54c \\(\\vec{x}+\\vec{\\epsilon}=(-1+0.1, 0+0.1)=(-0.9, 0.1)\\) \uc740 \\(x_1+x_1x_2+1=0\\) \uc744 \ub9cc\uc871\ud558\uc9c0 \uc54a\ub294\ub2e4.<\/p>\n

\ub9cc\uc57d \uc5b4\ub5a4 \uc810 \\(\\vec{x_a}\\) \uac00 \\(g(\\vec{x_a})=0\\) \uc744 \ub9cc\uc871\ud560 \ub54c, \\(g(\\vec{x_a}+\\vec{\\epsilon})=0\\) \uac00 \ub418\ub294 \uac83\uc740 \uc27d\uc9c0 \uc54a\uc740 \uc77c\uc774\ub2e4. \uadf8\ub807\ub2e4\uba74 \\(g(\\vec{x_a}+\\vec{\\epsilon})=0\\) \uac00 \ub418\ub824\uba74 \\(\\vec{\\epsilon}\\) \uc740 \uc5b4\ub5a4 \uc870\uac74\uc744 \ub9cc\uc871\ud574\uc57c \ud558\ub294\uac00?<\/p>\n

\\(g(\\vec{x_a}+ \\vec{\\epsilon}) = g(\\vec{x_a})\\) \uac00 \ub418\ub824\uba74 \\(\\nabla g(\\vec{x_a}) \\cdot \\vec{\\epsilon}\\) \uac00 \\(0\\) \uc774 \ub418\uba74 \ub41c\ub2e4. \uc704\uc758 \uc2dd\uc744 \ud655\uc778\ud558\uc790.<\/p>\n

\uadf8\ub9ac\uace0 \\(\\nabla g(\\vec{x}) \\cdot \\vec{\\epsilon}=0\\) \uc740 \ub450 \ubca1\ud130 \\(\\nabla g(\\vec{x})\\) \uacfc \\(\\vec{\\epsilon}\\) \uc758 \uc0ac\uc787\uac01\uc774 90\ub3c4<\/strong>\uc784\uc744 \ub098\ud0c0\ub0b8\ub2e4.<\/p>\n

\uc774 \uacb0\uacfc\ub97c \uc801\uc6a9\ud574\ubcf4\uc790. \\(g(\\vec{x})=0\\) \uc744 \ub9cc\uc871\ud558\uba74\uc11c \\(f(\\vec{x})\\) \ub97c \ucd5c\ub300\ud654\ud558\ub824\uace0 \ud560 \ub54c, \ub354\uc774\uc0c1 \\(\\vec{\\epsilon}\\) \uc740 \ubaa8\ub4e0 \ubc29\ud5a5\uc744 \uace0\ub824\ud560 \ud544\uc694\uac00 \uc5c6\ub2e4. \\(g(\\vec{x})=0\\) \uc774\uace0, \ub9e4\uc6b0 \uc791\uc740 \\(\\vec{\\epsilon}\\) \uc5d0 \ub300\ud574 \\(g(\\vec{x}+\\vec{\\epsilon})=0\\) \uc774 \uc131\ub9bd\ud558\ub824\uba74, \\(\\nabla g(\\vec{x}) \\cdot \\vec{\\epsilon} = 0\\) \uc744 \ub9cc\uc871\ud574\uc57c \ud558\ubbc0\ub85c, \\(f(\\vec{x})\\) \ub97c \ucd5c\ub300\ud654\ud560 \ub54c\uc5d0\ub3c4 \\(\\nabla g(\\vec{x}) \\cdot \\vec{\\epsilon} = 0\\) \uc744 \ub9cc\uc871\ud558\ub294 \\(\\vec{\\epsilon}\\) \ub9cc\uc744 \uace0\ub824\ud558\uba74 \ub41c\ub2e4. <\/p>\n

\\(f(\\vec{x} + \\vec{\\epsilon}) \\approx f(\\vec{x}) + \\nabla f(\\vec{x}) \\cdot \\vec{\\epsilon}\\) s.t. \\(g(\\vec{x}) = 0\\)<\/h4>\n

\uc790, \ub2e4\uc2dc \\(f(\\vec{x} + \\vec{\\epsilon}) \\approx f(\\vec{x}) + \\nabla f(\\vec{x}) \\cdot \\vec{\\epsilon}\\) \uc744 \ubcf4\uc790. \uc774\ubc88\uc5d0\ub294 \ubb34\uc81c\uc57d<\/strong>(\uc5b4\ub5a4 \\(\\vec{\\epsilon}\\) \ub3c4 \uac00\ub2a5)\uc774 \uc544\ub2c8\ub77c, \\(g(\\vec{x})=0\\) \uc744 \ub9cc\uc871\ud558\ub294 \uc81c\uc57d\uc5d0\uc11c \uc0b4\ud3b4\ubcf4\uc790.<\/p>\n

\ub2e4\uc2dc \ub9d0\ud574, \\(\\nabla g(\\vec{x}) \\cdot \\vec{\\epsilon} = 0\\) \uc744 \ub9cc\uc871\ud558\ub294 \ubaa8\ub4e0 \\(\\vec{\\epsilon}\\) \uc5d0 \ub300\ud574 \\(\\nabla f(\\vec{x}) \\vec{\\epsilon}=0\\) \uc744 \ub9cc\uc871\uc2dc\ud0a4\ub824\uba74 \uc5b4\ub5a4 \uc870\uac74\uc774 \ud544\uc694\ud55c\uac00?<\/p>\n

\uc81c\uc57d \ud558\uc758 \ucd5c\uc801\ud654: \uadf8\ub798\ub514\uc5b8\ud2b8\uc758 \uad00\uc810<\/h3>\n

\\(\\nabla g(\\vec{x}) \\cdot \\vec{\\epsilon} = 0\\) \uc744 \ub9cc\uc871\ud558\ub294 \ubaa8\ub4e0 \\(\\vec{\\epsilon}\\) \uc5d0 \ub300\ud574 \\(\\nabla f(\\vec{x}) \\cdot \\vec{\\epsilon}=0\\) \uc744 \ub9cc\uc871\uc2dc\ud0a4\ub824\uba74 \uc5b4\ub5a4 \uc870\uac74\uc774 \ud544\uc694\ud55c\uac00?<\/p>\n

\uc774 \uc870\uac74\uc740 \\(g(\\vec{x})=0\\) \uc744 \ub9cc\uc871\ud558\uace0, \\(f(\\vec{x})\\) \ub97c \ucd5c\ub300\/\ucd5c\uc18c\ud654\ub294 \uc810 \\(\\vec{x_{\\textrm{optim}}}\\) \uc758 \uc870\uac74\uc744 \uadf8\ub798\ub514\uc5b8\ud2b8\ub85c \ud45c\ud604\ud55c \uac83\uc774\ub77c\uace0 \ud560 \uc218 \uc788\ub2e4.<\/p>\n

\\(g(\\vec{x})=0\\) \uc744 \ub9cc\uc871\ud558\ub294 \uc810 \\(\\vec{x}\\) \uc640 \uadf8 \uc8fc\ubcc0\uc758 \uc810 \\(\\vec{x}+\\vec{\\epsilon}\\) \uc744 \uc0dd\uac01\ud574\ubcf4\uc790. \uad6d\uc18c\uc801\uc73c\ub85c( \\(\\vec{\\epsilon}\\) \uc758 \ud06c\uae30\uac00 \ub9e4\uc6b0 \uc791\uc744 \ub54c), \\(\\nabla g(\\vec{x}) \\cdot \\vec{\\epsilon} = 0\\) \uc744 \ub9cc\uc871\ud574\uc57c \ud55c\ub2e4.<\/p>\n

\\(f(\\vec{x})\\) \uac00 \ucd5c\ub300\/\ucd5c\uc18c\uc810\uc774\ub77c\uba74 \\(\\vec{x}\\) \ub294 \uad6d\uc18c\uc801\uc73c\ub85c \\(\\nabla f(\\vec{x}) \\cdot \\vec{\\epsilon} = 0\\) \uc744 \ub9cc\uc871\ud55c\ub2e4. <\/p>\n

\uc790 \uadf8\ub807\ub2e4\uba74 \\(\\nabla g(\\vec{x}) \\vec{\\epsilon} = 0\\) \uc744 \ub9cc\uc871\ud558\ub294 \ubaa8\ub4e0 \\(\\vec{\\epsilon}\\) \uc5d0 \ub300\ud574 \\(\\nabla f(\\vec{x}) \\vec{\\epsilon}=0\\) \uc744 \ub9cc\uc871\uc2dc\ud0a4\ub824\uba74 \uc5b4\ub5a4 \uc870\uac74\uc774 \ud544\uc694\ud55c\uac00?<\/p>\n

\uad6c\uccb4\uc801\uc778 \uc608<\/h4>\n

\ub2e4\uc2dc \uad6c\uccb4\uc801\uc778 \uc608\ub85c \ub3cc\uc544\uac00\ubcf4\uc790.<\/p>\n

\\(1+ x_1 + x_1 x_2 = 0\\) \uc77c \ub54c, \\(x_1^2 + x_2^2\\) \ub97c \ucd5c\uc18c\ud654\ud574\ubcf4\uc790.<\/p>\n

\uc6b0\uc120 \\(f(x_1, x_2)\\) \uc758 \uc804\uc5ed \ucd5c\uc18c\ud654\uc810 \\((0,0)\\) \uc774 \\(1+ x_1 + x_1 x_2 = 0\\) \ub97c \ub9cc\uc871\ud558\ub294\uc9c0 \ud655\uc778\ud55c\ub2e4. \ub9cc\uc871\ud558\uc9c0 \uc54a\ub294\ub2e4.<\/p>\n

\ub2e4\uc74c\uc73c\ub85c \\(\\nabla g(x_1, x_2) \\cdot \\vec{\\epsilon} = 0\\) \uc744 \ub9cc\uc871\ud558\ub294 \\(\\vec{\\epsilon}\\) \uc5d0 \ub300\ud574 \\(\\nabla f(x_1, x_2) \\cdot \\vec{\\epsilon} =0\\) \uc744 \ub9cc\uc871\ud558\ub824\uba74?<\/p>\n

\uad6c\uccb4\uc801\uc73c\ub85c \\(\\nabla f(1,2) = (2,4)\\) \uc774\ub2e4. \ubb34\uc81c\uc57d\ud558\uc5d0\uc11c\ub3c4 \ucd5c\ub300\/\ucd5c\uc18c\ub294 \uc544\ub2c8\ub2e4. \\(\\nabla g \\cdot \\vec{\\epsilon} = (3,1)\\cdot \\vec{\\epsilon}=0\\) \uc744 \ub9cc\uc871\ud558\ub294 \ubaa8\ub4e0 \\(\\vec{\\epsilon}\\) \uc5d0 \ub300\ud574 \\(\\nabla f(x_1, x_2) \\cdot \\vec{\\epsilon} = (2, 4)\\cdot \\vec{\\epsilon} = 0\\) \uc744 \ub9cc\uc871\ud558\ub294\uac00?<\/p>\n

\uc608\ub97c \ub4e4\uc5b4 \\(\\vec{\\epsilon}=(2,-1)\\) \uc77c \ub54c, \\(\\nabla g(1,2)\\cdot (2,-1)=6-1=5\\) \ub85c \\((1,2)\\) \uc5d0\uc11c \\((2,-1)\\) \ub85c \uc774\ub3d9\ud560 \uacbd\uc6b0 \\(g(\\vec{x})\\) \uc758 \uac12\uc774 \ubcc0\ud558\uac8c \ub41c\ub2e4\ub294 \uac83\uc744 \uc54c \uc218 \uc788\ub2e4. <\/p>\n

\\(x_1, x_2\\) \ub97c \ubbf8\uc9c0\uc218\ub85c \ub450\uace0 \ud480\uc5b4\ubcf4\uba74, \\((1+x_2,x_1)\\cdot(\\epsilon_1, \\epsilon_2) = (1+x_2)\\epsilon_1 + x_1 \\epsilon_2 = 0\\) \uc5d0\uc11c \\(\\epsilon_1=-\\frac{x_1}{1+x_2}\\epsilon_2\\) \uc784\uc744 \uc54c \uc218 \uc788\ub2e4. \ubaa8\ub4e0 \\(\\epsilon_2\\) \uc5d0 \ub300\ud574 \\(\\nabla f(x_1,x_2)\\cdot (\\epsilon_1, \\epsilon_2)=0\\) \uc774 \ub418\ub824\uba74 \\(x_1, x_2\\) \ub294 \uc5b4\ub5a4 \uac12\uc774 \ub418\uc5b4\uc57c \ud560\uae4c? \\(\\nabla f(x_1, x_2)\\cdot (\\epsilon_1, \\epsilon_2) = (2x_1,2x_2)\\cdot(-\\frac{x_1}{1+x_2}\\epsilon_2, \\epsilon_2)=-(\\frac{2x_1^2}{1+x_2} + 2x_2)\\epsilon_2 = 0\\) \uc778 \ubaa8\ub4e0 \\(\\epsilon_2\\) \uc5d0 \ub300\ud574 \uc131\ub9bd\ud558\ub824\uba74, \\((-\\frac{2x_1^2}{1+x_2} + 2x_2)\\) \uac00 \\(0\\) \uc774 \ub418\uc5b4\uc57c \ud55c\ub2e4.<\/p>\n

\uadf8\ub9ac\uace0 \\(g(\\vec{x}) = 0\\) \uc774\ubbc0\ub85c \\(1+x_1 + x_1x_2=0\\) \uc774\ub2e4.<\/p>\n

\ub530\ub77c\uc11c \ub2e4\uc74c\uc758 \ub450 \ub4f1\uc2dd\uc744 \ubaa8\ub450 \ub9cc\uc871\ud558\ub294 \\(x_1, x_2\\) \uac00 \uc81c\uc57d\ud558\uc758 \\(f(\\vec{x})\\) \uc744 \ucd5c\ub300\/\ucd5c\uc18c\ud654\ud558\ub294 \ud6c4\ubcf4\uac00 \ub41c\ub2e4.<\/p>\n

\\(-\\frac{x_1^2}{1+x_2} + 2x_2 = 0\\)<\/p>\n

\\(1+x_1+x_1x_2=0\\)<\/p>\n

\"\"\/<\/p>\n

(\uc704\uc758 \uadf8\ub798\ud504\ub294 https:\/\/cocalc.com<\/a> \uc5d0\uc11c \ub2e4\uc74c\uc758 \ucf54\ub4dc\ub85c \uc791\uc131\ub418\uc5c8\ub2e4.<\/p>\n

p1 = implicit_plot3d(x+x*y + 1 == 0, (x,-3,3), (y,-3,3), (z,-3,3), texture='blue', mesh=True)\np2 = implicit_plot3d(x^2+y^2 == z, (x,-3,3), (y,-3,3), (z,-3,3), texture='red', mesh=True)\np1 + p2\n<\/pre>\n
)<\/p>\n
\uac04\ub2e8\ud558\uac8c<\/h4>\n
\ub450 \uc870\uac74\uc744 \ub2e4\uc2dc \uc368\ubcf4\uc790.<\/p>\n
\\(\\nabla g(\\vec{x})\\cdot \\vec{\\epsilon}=0\\)<\/p>\n
\\(\\nabla f(\\vec{x})\\cdot \\vec{\\epsilon}=0\\)<\/p>\n
\uccab \ubc88\uc9f8 \uc2dd\uc5d0\uc11c \ub450 \ubc88\uc9f8 \uc2dd\uc744 \ube7c\uba74, \\(\\nabla g(\\vec{x})\\cdot \\vec{\\epsilon} – \\nabla f(\\vec{x})\\cdot \\vec{\\epsilon}=0\\) \uc774\uace0, \\(\\left( \\nabla g(\\vec{x}) – \\nabla f(\\vec{x}) \\right)\\cdot \\vec{\\epsilon} =0\\) \uc744 \uc5bb\uc744 \uc218 \uc788\ub2e4.<\/p>\n
\ub9cc\uc57d \ubaa8\ub4e0 \\(\\vec{\\epsilon}\\) \uc5d0 \ub300\ud574 \\(\\left(\\nabla g(\\vec{x}) – \\nabla f(\\vec{x}) \\right)\\cdot \\vec{\\epsilon} =0\\) \uc774 \uc131\ub9bd\ud558\uae38 \uc6d0\ud55c\ub2e4\uba74, \\(\\nabla g(\\vec{x}) = \\nabla f(\\vec{x})\\) \uc774 \uc131\ub9bd\ud574\uc57c \ud55c\ub2e4.<\/p>\n
\ud558\uc9c0\ub9cc \uc7a0\uae50!<\/p>\n
\uc704\uc5d0\uc11c \ubaa8\ub4e0 \ubc29\ud5a5\uc5d0 \ub300\ud574 \uace0\ub824\ud560 \ud544\uc694\uac00 \uc5c6\ub2e4\uace0 \ud588\uc796\uc544?<\/p>\n
\ub77c\uadf8\ub791\uc950 \uc2b9\uc218\ubc95\uc744 \uc554\uae30\ud558\ub294 \uc6b0\ub9ac\uc758 \uc790\uc138<\/h3>\n
"\uac70\uc758 \ubaa8\ub4e0 \uc218\ud559\uc740 \uc554\uae30\ud574\uc11c \uc801\uc808\ud788 \uc801\uc6a9\ud558\uba74 \uadf8\ub9cc\uc774\ub2e4"\ub780 \uc8fc\ub958 \ucca0\ud559\uacc4\uc758 \uc8fc\uc7a5\uc744 \ubc1b\uc544\ub4e4\uc778\ub2e4\uba74,<\/p>\n
\\(g(\\vec{x})=0\\) \uc744 \ub9cc\uc871\ud558\uba74\uc11c, \\(f(\\vec{x})\\) \uc744 \ucd5c\ub300 \ud639\uc740 \ucd5c\uc18c\ud654\ud558\ub824\uba74,<\/p>\n
\\(\\nabla f(\\vec{x}) – \\lambda g(\\vec{x}) = 0\\) \uacfc \\(g(\\vec{x})=0\\) \uc744 \ub9cc\uc871\ud558\ub294 \\(\\vec{x}\\) \uc744 \uad6c\ud558\uba74 \ub41c\ub2e4.<\/p>\n
\uc704\uc758 \uc608\ub97c \ubcf4\uc790. \\(f(\\vec{x}) = x_1^2 + x_2^2\\) \uc774\uace0 \\(\\nabla(f) =(2x_1, 2x_2)\\) \uc774\ub2e4.
\n\\(g(\\vec{x}) = x_1 + x_1x_2 + 1\\) \uc774\uace0, \\(\\nabla(g) = (1+x_2, x_1)\\) \uc774\ub2e4.<\/p>\n
\uc774\uc81c \ub77c\ub974\ub791\uc950 \ubc29\ubc95\uc5d0 \uc758\ud574 \\(f(\\vec{x})\\) \uc744 \ucd5c\ub300\/\ucd5c\uc18c\ud654\ud558\ub294 \\(\\vec{x}=(x_1, x_2)\\) \ub294 \ub2e4\uc74c\uc744 \ub9cc\uc871\ud55c\ub2e4.<\/p>\n
\\[(2x_1, 2x_2) = \\lambda (1+x_2, x_1)\\]<\/p>\n
\\[x_1 + x_1 x_2 + 1 = 0\\]<\/p>\n
\\(2x_1 = \\lambda( 1+x_2)\\) \uc640 \\(2x_2 = \\lambda x_1\\) \uc5d0\uc11c \\(\\lambda\\) \ub97c \uc81c\uac70\ud558\ub824\uba74 ( \\(\\lambda \\neq 0\\) ), \uccab \ubc88\uc9f8 \uc2dd\uc5d0\uc11c \ub450 \ubc88\uc9f8 \uc2dd\uc744 \ub098\ub208\ub2e4.<\/p>\n
\\[\\frac{x_1}{x_2} = \\frac{1+x_2}{x_1}\\]<\/p>\n
\ub530\ub77c\uc11c \ub2e4\uc74c\uc758 \ub450 \uc2dd\uc744 \ubaa8\ub450 \ub9cc\uc871\ud558\ub294 \\((x_1, x_2)\\) \uad6c\ud558\uba74 \ub41c\ub2e4.<\/p>\n
\\(x_1 + x_1x_2 + 1 =0\\), \\(x_1^2 = (1+x_2)x_2\\)<\/p>\n
\uccab \ubc88\uc9f8 \uc2dd\uc5d0\uc11c \\(x_1(1+x_2) = -1\\) , \\(x_1 =  \\frac{-1}{1+x_2}\\) \uc744 \uc5bb\uace0 \uc774 \uc2dd\uc744 \uc544\ub798 \uc2dd\uc5d0 \ub300\uc785\ud558\uba74,<\/p>\n
\\[\\frac{1}{(1+x_2)^2} = (1+x_2)x_2\\]<\/p>\n
\\(1 = (1+x_2)x_2(1+x_2)^2\\) \uc744 \uc798<\/strong> \ud480\uc5b4\ubcf4\uba74, \\(x_2 \\approx -1.8192, 0.38028\\) \uc744 \uc5bb\uc744 \uc218 \uc788\ub2e4.3<\/sup><\/a><\/p>\n
\uc774 \uac12\uc744 \uc774\uc6a9\ud574 \\(x_1\\) \uc744 \uad6c\ud558\uace0 \\(f(x_1, x_2)\\) \uc744 \uad6c\ud55c \ud6c4, \uadf8 \uac12\uc911\uc5d0\uc11c \ucd5c\ub300\/\ucd5c\uc18c\uac12\uc744 \ucc3e\uc744 \uc218 \uc788\ub2e4.<\/p>\n
\ud480\uc5b4\ubcf4\ub2c8 \uad1c\ucc2e\uc740 \uc608\uac00 \uc544\ub2c8\uc5c8\ub2e4\ub294 \uc0dd\uac01\uc774 \ub4e0\ub2e4. (\uae54\ub054\ud788 \ub5a8\uc5b4\uc9c0\ub294 \uc608\uc81c\ub97c \ub9cc\ub4dc\ub294 \uac83\ub3c4 \uc27d\uc9c0 \uc54a\uc740 \uc77c\uc774\ub2e4.)<\/p>\n
\uc5b4\uca0b\ub4e0 \uc774 \ubc29\ubc95\uc774 \uc218\uce58\uc801\uc774 \ubc29\ubc95\ubcf4\ub2e4 \ub098\uc740 \uc810\uc740 \uc815\ud655\ud55c \ud574<\/strong>(\uc218\uce58\uc801\uc73c\ub85c \ud47c \uadfc\uc0ac\ud574\uac00 \uc544\ub2c8\ub77c)\ub97c \uc5bb\uc744 \uc218 \uc788\ub2e4\ub294 \uc810, \uadf8\ub9ac\uace0 \ud568\uc218 \\(f\\) \ub610\ub294 \\(g\\) \uc5d0 \ubb38\uc790 \\(a\\) , \\(b\\) , \\(c\\) \ub4f1\uc774 \ud3ec\ud568\ub418\uc5b4 \uc788\uc5b4\ub3c4 \ud480 \uc218 \uc788\ub2e4\ub294 \uc810\uc774 \uc788\ub2e4!<\/p>\n
\ub77c\uadf8\ub791\uc950 \uc2b9\uc218\ubc95\uc744 \uc774\ud574\ud558\ub294 \uc6b0\ub9ac\uc758 \uc790\uc138<\/h3>\n
\ub2e4\uc74c\uc758 \uc870\uac74\uc744 \ubcf4\uc790. <\/p>\n
\\(\\nabla g(\\vec{x})\\cdot \\vec{\\epsilon}=0\\)<\/p>\n
\uc774\ub54c \\(\\lambda_1\\neq 0\\) \uc774\ub77c\uba74, \\(\\lambda_1(\\nabla g(\\vec{x})\\cdot \\vec{\\epsilon})=0\\) \uacfc \uc704\uc758 \uc2dd\uc740 \ub3d9\uce58<\/strong>\uc774\ub2e4.<\/p>\n
\\(\\nabla f(\\vec{x})\\cdot \\vec{\\epsilon}=0\\) \uc5d0 \ub300\ud574\uc11c\ub3c4 \ub3d9\uc77c\ud55c \uc598\uae30\ub97c \ud560 \uc218 \uc788\uc9c0\ub9cc \uc0dd\ub7b5\ud558\uc790.<\/p>\n
\uc774\uc81c \\(\\nabla g(\\vec{x})\\cdot \\vec{\\epsilon}=0\\) \uc744 \ub9cc\uc871\ud558\ub294 \\(\\vec{\\epsilon}\\) \uc5d0 \ub300\ud574 \\(\\nabla f(\\vec{x})\\cdot \\vec{\\epsilon}=0\\) \uc744 \ub9cc\uc871\uc2dc\ud0a4\ub294 \ubc29\ubc95\uc740 \uc5c6\uc744\uae4c?<\/p>\n
3\ucc28\uc6d0 \uacf5\uac04\uc744 \uc0dd\uac01\ud574\ubcf4\uc790. \\(\\vec{a} \\cdot \\vec{x} =0\\) ( \\(\\vec{a}\\) \uc0c1\uc218, \\(\\vec{x}\\) \ubcc0\uc218) \ub294 \uc6d0\uc810 \\(\\vec{0}\\) \uc744 \uc9c0\ub098\uace0 \ubca1\ud130 \\(\\vec{a}\\) \uc5d0 \uc218\uc9c1\uc778 \ud3c9\uba74\uc744 \ub098\ud0c0\ub0b8\ub2e4. <\/p>\n
\uc774 \ud3c9\uba74\uc758 \ubaa8\ub4e0 \uc810\uc740 \\(\\lambda \\vec{a} \\cdot \\vec{x}=0\\) ( \\(\\lambda \\neq 0\\) )\uc758 \uaf34\ub85c \ub098\ud0c0\ub0bc \uc218 \uc788\ub2e4. <\/p>\n
\ub530\ub77c\uc11c \\(f(\\vec{x}) = \\lambda g(\\vec{x})\\) \uc744 \ub9cc\uc871\ud574\uc57c \ud55c\ub2e4.<\/p>\n
\uc774\ub54c \\(\\lambda \\neq 0\\) \uc870\uac74\uc774 \ucd5c\ub300\/\ucd5c\uc18c\uac12\uc744 \uad6c\ud558\ub294\ub370\uc5d0\ub294 \uc911\uc694\ud558\uc9c0 \uc54a\uc74c\uc744 \uc720\uc758\ud558\uc790. \uc65c\ub0d0\ud558\uba74 \\(\\lambda =0\\) \uc77c\ub54c, \\(f(\\vec{x})=\\vec{0}\\) \uc774\uace0, \\(g(\\vec{x})=0\\) \uacfc \\(f(\\vec{x})=0\\) \uc744 \ub9cc\uc871\ud558\uba74 \\(f(\\vec{x})\\) \ub3c4 \ucd5c\ub300\/\ucd5c\uc18c\uac12 \ud6c4\ubcf4\uac00 \ub418\uae30 \ub54c\ubb38\uc774\ub2e4. <\/p>\n
\uc219\uc81c<\/h3>\n
\uc81c\uc57d \uc870\uac74\uc774 \ub450 \uac1c \uc774\uc0c1\uc77c \ub54c\uc640, KKT(Karush-Kuhn_tucker) \uc870\uac74\uc5d0 \ub300\ud574 \uc720\ub3c4\ud558\uace0, \uc774\ud574\ud558\uace0, \uc124\uba85\ud574 \ubcf4\uc138\uc694.<\/p>\n","protected":false},"excerpt":{"rendered":"
PRML(Pattern Recognition and Machine Learning)\uc774\ub780 \ucc45\uc774 \uc788\ub2e4. Christopher M. Bishop\uc774 \uc4f4 \uc774 \ucc45\uc740 ML\uc758 \ubc14\uc774\ube14\uc774\ub77c\uace0 \uc77c\uceeb\ub294\ub2e4. \ub300\ud559\uc6d0\uc5d0 \uc788\uc744 \ub54c\uc5d0\ub3c4 \ub204\uad70\uac00 \uc9c8\ubb38\uc744 \ud560 \ub54c\uc5d0\uba74, “\uadf8\uac70 PRML\uc5d0 \uc788\uc5b4!"\ub77c\uace0 \ub300\ub2f5\ud558\uae30\ub3c4 \ud588\ub2e4\ub294… \ud558\uc9c0\ub9c8 \ub098\ub294 \uadf8\ub2e4\uc9c0 \uc88b\uc544\ud558\uc9c0 \uc54a\uc558\ub2e4. \uc9c0\uae08 \ubd10\ub3c4 '\uc815\ub9ac\ub294 \uc798 \ud588\ub124'\ub77c\ub294 \ud3c9\uac00\ub97c \ub0b4\ub9b4 \uc21c \uc788\ub2e4. \ud558\uc9c0\ub9cc \ucd08\uc2ec\uc790\uc5d0\uac8c \uc88b\uc740 \uc811\uadfc \ubc29\ubc95\uc774\ub0d0? \uc774\ud574\ud558\uae30 \uc27d\ub0d0?\ub77c\uace0 \ubb3c\uc5c8\uc744 \ub54c\ub294 \uc8fc\uc800\ud560 \uc218 \ubc16\uc5d0 \uc5c6\ub2e4.[1] […]<\/p>\n","protected":false},"author":1,"featured_media":2001,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[319],"tags":[391,392],"jetpack_featured_media_url":"http:\/\/ds.sumeun.org\/wp-content\/uploads\/2019\/10\/LagrangeMul.png","_links":{"self":[{"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/posts\/1999"}],"collection":[{"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1999"}],"version-history":[{"count":3,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/posts\/1999\/revisions"}],"predecessor-version":[{"id":2003,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/posts\/1999\/revisions\/2003"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=\/wp\/v2\/media\/2001"}],"wp:attachment":[{"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1999"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1999"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/ds.sumeun.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1999"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}