เอกสารการประชุมวิชาการและเสนอผลงานวิจัย มหาวิทยาลัยทักษิณ ครั้งที่ 19 2552 - page 181

„µ¦ž¦³»¤ª·µ„µ¦Â¨³Áœ°Ÿ¨Šµœª·‹´¥ ¤®µª·š¥µ¨´¥š´„¬·– ‡¦´ÊŠš¸É 19 ž¦³‹Îµže 2552
4
1 ™o µ 0 * !
i Y
i Y = (3)
0 ™o µ 0 * d
i Y
‹µ„¤„µ¦ (2) ¨³ (3) oµŠ˜oœ ‹³Å—oªnµ
1 YP = E ,
i i X eP !
= E ' 1 i X )
= E '
i X ) (4)
×¥š¸É ) ‡º° ¢{Š„r´œ„µ¦Â‹„‹Š³¤ (Cumulative Distribution Function) °Š‡n µ‡ªµ¤‡¨µ—Á‡¨ºÉ°œš¸É¤¸¦¼žÂ„µ¦
‹„‹ŠÂž„˜·
ÁoœÃ‡oŠ ROC (Receiver Operating Characteristic curve)
Áo œÃ‡oŠ ROC Áž}œ„¦µ¢š¸É¡¨È°˜¦³®ªnµŠ‡nµ sensitivity ( SN ) ®¦º°´—nªœ °Š„µ¦¡¥µ„¦–rŗo™¼„˜o°Š °Š„µ¦
Á„·—Á®˜»„µ¦–rš¸É œÄ‹ ¨³‡nµ 1 - specificity ( SP ) ®¦º°´ —nªœ °Š„µ¦¡¥µ„¦–r Ÿ·— °Š„µ¦Á„·—Á®˜»„µ¦–r š¸É œÄ‹
(Thomas A. Lasko ¨³‡–³, 2005)
¡ºÊœš¸É ĘoÇoŠ ROC (Area under the ROC Curve ( AUC ))
¡ºÊ œš¸ÉĘoÇoŠ ROC čoÁž} œ—´œ¸Äœ„µ¦n Š¸Ê‡ªµ¤™¼„˜o°Š °Š„µ¦¡¥µ„¦–r®¦º°‡ªµ¤ÁºÉ°™º°Å—o°Š˜´ªÂ Ž¹ÉŠ
—ŠÄ®oÁ®Èœ™¹Š‡ªµ¤µ¤µ¦™Äœ„µ¦‹ÎµÂœ„„¨»n¤Á®˜»„µ¦–rš¸É œÄ‹°°„‹µ„„¨»n ¤Á®˜»„µ¦–r š¸ÉŤn œÄ‹ ץĜ„µ¦‡Îµœª–
‡nµž¦³¤µ–¡ºÊœš¸ÉĘoÇoŠ ROC ( CUA ˆ ) µ¤µ¦™‡Îµœª–Å—o®¨µ¥ª·›¸ 宦´ÄœŠµœª·‹´¥œ¸Ê°„¨nµª°oµŠ™¹Š¦³Á¸¥ª·›¸š¸ÉŤnčo
¡µ¦µ¤·Á˜°¦r (Nonparametric Method)ץĜ„µ¦¦oµŠÁoœÃ‡o Š ROC ‹³ÁºÉ°¤˜n°Â˜n¨³‹»— °Š o°¤¼¨Ž¹É Š¤¸‡nµ 1 - specificity
°¥¼nĜœªÂ„œ x ¨³ sensitivity °¥¼nĜœªÂ„œ y SN SP , 1 Áž}œÁoœ˜¦Š ®¨´Š‹µ„œ´ÊœšÎµ„µ¦ž¦³¤µ–‡nµ¡ºÊœš¸ÉĘo
ÇoŠ ROC ×¥°µ«´¥®¨´„Á„–”rÁ·Š¸ÉÁ®¨¸É¥¤‡µŠ®¤¼ (Trapezoidal Rule) Ž¹ÉŠª·›¸„µ¦—´Š„¨nµªÁž} œ„µ¦°oµŠ¦³Á¸¥ ´Êœ˜°œšµŠ
™· ˜·š¸ÉŤn čo¡µ¦µ¤· Á˜°¦r ×¥‡nµž¦³¤µ– °Š¡ºÊœš¸ÉĘoÇoŠ ROC ‹µ„ª·›¸„µ¦œ¸Ê ‹³¤¸‡nµÁšn µ„´Ÿ¨„µ¦š—° o°¤¼¨»—Á—·¤
—oª¥„µ¦š—° °ŠÂ¤œ-ª·šœ¸ ¥r (Mann –Whitney Test ) Ž¹ÉŠÁž}œ„µ¦š—°Ã—¥„µ¦‡Îµœª–‡nµ‹µ„‹Îµœªœ‡¼nš¸É¤¸‡ªµ¤
Áž}œÅžÅ—o°ŠÁ®˜»„µ¦–rš¸É œÄ‹„´Á®˜»„µ¦–r š¸ÉŤn œÄ‹ ×¥Áž}œÂœª‡ªµ¤‡·—Á—¸¥ª„´„µ¦š—°Ÿ¨¦ª¤°´œ—´ °Š
ª·¨‡°„Ž´œ (Wilcoxon Rank – Sum Test) ¨³„µ¦š—°C-index (Thomas A. Lasko ¨³‡–³, 2005)
×¥„Î µ®œ—Ä®o D n d dd ,..., , 2 1 Áž} œ‡nµ¡¥µ„¦–r 宦´„¨»n¤Á®˜»„µ¦–rš¸É œÄ‹
H n h hh ,..., , 2 1 Áž} œ‡nµ¡¥µ„¦–r 宦´„¨»n¤Á®˜»„µ¦–rš¸ÉŤn œÄ‹
D n Áž} œ‹Îµœªœ‡nµ¡¥µ„¦–r˜´ª°¥nµŠ‹µ„„¨»n¤Á®˜»„µ¦–rš¸É œÄ‹
H n Áž} œ‹Îµœªœ‡nµ¡¥µ„¦–r˜´ª°¥nµŠ‹µ„„¨»n¤Á®˜»„µ¦–rš¸ÉŤn œÄ‹
¨³ j i hdC , Áž}œ¢{ Š„r´œš¸ÉčoĜ„µ¦Áž¦¸ ¥Áš¸¥ Á¤ºÉ°
1 ™o µ j i h d !
j i hdC , = 5.0 ™o µ j i h d (5)
0 ™o µ j i h d