... 2.2 String kernel 39 2.2.1 Kernel da trờn mụ hỡnh k_gram 39 2.2.2 Kernel da trờn trng s ca cỏc xõu 41 2.2.3 Tớnh string kernel dựng quy hoch ng .43 2.2.4 Kernel ... l i kernel tha |k (x,x,)| < p vi x, x, thỡ f o k l kernel cú hiu lc (kernel xỏc nh dng) Vớ d vi mi kernel k, exp(k) l kernel hiu lc v mi k b chn |k|...