(1, 0 , 0)と(s*, 0, r*) 8/20 t→∞としたときに感染者は0⼈になり、 s* (= s(∞)): 何%が感染を逃れたか r* (= r(∞)): 何%が感染したか <latexit sha1_base64="GZ7GT/t1BrHuSYH75Oq0B+oFT9Y=">AAACunicfVFda9RAFJ2NH63xo1t99GVwUUTskohVHyoU9cEXsYLbFjbLcjO5SYedyYSZG3EJ+Yf+Af+Gr/rgZJsVuxUvDBzOOXfu3DNppaSjKPo+CK5cvXZ9a/tGePPW7Ts7w927x87UVuBEGGXsaQoOlSxxQpIUnlYWQacKT9LF204/+YLWSVN+pmWFMw1FKXMpgDw1H+aPkiy3IJrMtU1GLX/N95IUCbjjkidJ+EeXa533uuR7PClAa9hw2rVzrYbhfDiKxtGq+GUQ92DE+jqa7w4OksyIWmNJQoFz0ziqaNaAJSkUtmFSO6xALKDAqYclaHSzZhVIyx96JuO5sf6UxFfs3x0NaOeWOvVODXTmNrWO/Jc2rSl/NWtkWdWEpTgflNeKk+FdujyTFgWppQcgrPRv5eIMfCrk/+DClO5uMkY5v8o79Cta/OCpjxVaIGOfNAnYQsuy9SsXydMO/c8IX9dGj1Z5x5vpXgbHz8bxi/H+p+ejwzd98tvsPnvAHrOYvWSH7D07YhMm2Df2g/1kv4KDIA1ksDi3BoO+5x67UAH9BsO72J4=</latexit> ds dt = si di dt = si i dr dt = i <latexit sha1_base64="TWw88aSbJzklo45MPjvq1kp19nw=">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</latexit> s = S N , i = I N , r = R N <latexit sha1_base64="Aw425Lop8YfQ4vugYIF3fQA859A=">AAACuXicfVHbjtMwEHXDbQm3LjzyYlGBEGKrBHGTAGkFPNAHxMLS3ZWaqpo4k9SsHUf2BFFF+UK+gM/gFV5wui3aC2IkS0fnnPF4jtNKSUdR9KMXnDt/4eKljcvhlavXrt/ob97cc6a2AsfCKGMPUnCoZIljkqTwoLIIOlW4nx6+6fT9r2idNOVnWlQ41VCUMpcCyFOzPt5LstyCaLLdtsmo5a/4VpIiAd/lI54k4V99tNb5Sh/xLZ4UoDXw0XHjp7VxLYbhrD+IhtGy+FkQr8CArWpnttl7mWRG1BpLEgqcm8RRRdMGLEmhsA2T2mEF4hAKnHhYgkY3bZZ5tPyuZzKeG+tPSXzJHu9oQDu30Kl3aqC5O6115L+0SU3582kjy6omLMXRoLxWnAzvwuWZtChILTwAYaV/Kxdz8KmQ/4ITU7q7yRjl/Cpv0a9o8b2nPlRogYx90CRgCy3L1q9cJA879D8jfFsbPVrmHZ9O9yzYezSMnw6ffHw82H69Sn6D3WZ32H0Ws2dsm71jO2zMBPvOfrJf7HfwIoBgHnw5sga9Vc8tdqIC9wfgutdU</latexit> dS dt = SI dI dt = SI I dR dt = I <latexit sha1_base64="xH6Y+u0OyWqjHpz+UFtZmTKuzBw=">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</latexit> r⇤ = 1 exp( r⇤R0) <latexit sha1_base64="y4Drxc9cmIJphOIsqsikfGkQF1o=">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</latexit> R0 ⌘ = log(1 r⇤) r⇤ 新しい基本再⽣産数 r*にてつい て解く (解析的には解けないので)数値計算 <latexit sha1_base64="lxjKR111eVZZbnFb7RGt1wYQNmw=">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</latexit> r⇤ ⇡ 1 exp( R0) R0 が⼤きいとき はr*≒1なので R0 だけから、最終的な流⾏規模が⾒積もれる! 求め⽅:上の3番⽬を1番⽬に代⼊し て積分するだけ