{"id":567,"date":"2017-05-02T19:02:14","date_gmt":"2017-05-02T18:02:14","guid":{"rendered":"https:\/\/rosetta.vn\/short\/?p=567"},"modified":"2017-05-02T19:02:14","modified_gmt":"2017-05-02T18:02:14","slug":"nguoi-dan-dau-cach-mang-wavelet-doat-giai-abel","status":"publish","type":"post","link":"https:\/\/rosetta.vn\/short\/2017\/05\/02\/nguoi-dan-dau-cach-mang-wavelet-doat-giai-abel\/","title":{"rendered":"Ng\u01b0\u1eddi d\u1eabn \u0111\u1ea7u “c\u00e1ch m\u1ea1ng wavelet\u201d \u0111o\u1ea1t gi\u1ea3i Abel"},"content":{"rendered":"
\n

Jean-Michel Morel, nh\u00e0 to\u00e1n h\u1ecdc \u1ee9ng d\u1ee5ng v\u00e0 l\u00e0 \u0111\u1ed3ng nghi\u1ec7p c\u1ee7a Meyer t\u1ea1i tr\u01b0\u1eddng \u00c9cole Normale Sup\u00e9rieure Paris-Saclay, n\u00f3i, \u201cKh\u00f4ng c\u00f3 nhi\u1ec1u v\u00ed d\u1ee5 v\u1ec1 nh\u1eefng kh\u00e1m ph\u00e1 to\u00e1n h\u1ecdc \u1ea3nh h\u01b0\u1edfng tr\u1ef1c ti\u1ebfp \u0111\u1ebfn x\u00e3 h\u1ed9i l\u1edbn nh\u01b0 v\u1eady\u201d.<\/p>\n

Nh\u1eefng thu\u1eadt to\u00e1n m\u00e1y t\u00ednh d\u1ef1a tr\u00ean wavelet n\u1eb1m trong s\u1ed1 nh\u1eefng c\u00f4ng c\u1ee5 chu\u1ea9n \u0111\u01b0\u1ee3c c\u00e1c nh\u00e0 nghi\u00ean c\u1ee9u s\u1eed d\u1ee5ng \u0111\u1ec3 x\u1eed l\u00ed, ph\u00e2n t\u00edch v\u00e0 l\u01b0u tr\u1eef th\u00f4ng tin. Ch\u00fang c\u0169ng c\u00f3 nh\u1eefng \u1ee9ng d\u1ee5ng trong ch\u1ea9n \u0111o\u00e1n y t\u1ebf, ch\u1eb3ng h\u1ea1n nh\u01b0 gi\u00fap \u0111\u1ea9y nhanh t\u1ed1c \u0111\u1ed9 ch\u1ee5p c\u1ed9ng h\u01b0\u1edfng t\u1eeb; v\u00e0 trong gi\u1ea3i tr\u00ed, ch\u00fang \u0111\u01b0\u1ee3c d\u00f9ng \u0111\u1ec3 m\u00e3 h\u00f3a nh\u1eefng b\u1ed9 phim c\u00f3 \u0111\u1ed9 ph\u00e2n gi\u1ea3i cao th\u00e0nh nh\u1eefng t\u1ec7p c\u00f3 dung l\u01b0\u1ee3ng v\u1eeba ph\u1ea3i.<\/p>\n

Sau c\u00f4ng tr\u00ecnh \u0111\u1ed9t ph\u00e1 \u2013 \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 cu\u1ed9c c\u00e1ch m\u1ea1ng wavelet \u2013 do Meyer d\u1eabn \u0111\u1ea7u v\u00e0o nh\u1eefng n\u0103m 1980, c\u00e1c s\u00e1ch gi\u00e1o khoa \u1edf nhi\u1ec1u l\u0129nh v\u1ef1c \u0111\u00e3 ph\u1ea3i vi\u1ebft l\u1ea1i ho\u00e0n to\u00e0n, theo Morel.<\/p>\n

Wavelet l\u00e0 s\u1ef1 m\u1edf r\u1ed9ng c\u1ee7a b\u1ed9 c\u00f4ng c\u1ee5 to\u00e1n h\u1ecdc Gi\u1ea3i t\u00edch Fourier do nh\u00e0 to\u00e1n h\u1ecdc Joseph Fourier kh\u1edfi x\u01b0\u1edbng v\u00e0o nh\u1eefng n\u0103m 1800. \u00d4ng ph\u00e1t hi\u1ec7n ra r\u1eb1ng c\u00f3 th\u1ec3 chia m\u1ed9t d\u1ea1ng s\u00f3ng t\u00edn hi\u1ec7u ph\u1ee9c t\u1ea1p th\u00e0nh nh\u1eefng th\u00e0nh ph\u1ea7n s\u00f3ng h\u00ecnh sin \u0111\u01a1n gi\u1ea3n h\u01a1n. T\u1ee9c l\u00e0, m\u1ed9t m\u1ea9u th\u00f4ng tin, ch\u1eb3ng h\u1ea1n nh\u01b0 m\u1ed9t n\u1ed1t nh\u1ea1c ho\u1eb7c m\u1ed9t t\u00edn hi\u1ec7u \u0111\u1ecba ch\u1ea5n, c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c th\u1ec3 hi\u1ec7n m\u1ed9t c\u00e1ch s\u00fac t\u00edch b\u1eb1ng c\u00e1ch s\u1eed c\u00e1c d\u1ee5ng k\u1ef9 thu\u1eadt Fourier.<\/p>\n

M\u1eb7c d\u00f9 tao nh\u00e3 v\u1ec1 m\u1eb7t to\u00e1n h\u1ecdc  nh\u01b0ng c\u00f4ng th\u1ee9c ban \u0111\u1ea7u c\u1ee7a Fourier kh\u00f4ng d\u1ec5 d\u00e0ng \u00e1p d\u1ee5ng cho nhi\u1ec1u lo\u1ea1i d\u1eef li\u1ec7u th\u1ef1c t\u1ebf, John Rognes, nh\u00e0 to\u00e1n h\u1ecdc t\u1ea1i \u0110\u1ea1i h\u1ecdc Oslo, ng\u01b0\u1eddi \u0111\u1ee9ng \u0111\u1ea7u \u1ee6y ban Gi\u1ea3i Abel, gi\u1ea3i th\u00edch.<\/p>\n

Nh\u1eefng n\u0103m 1900, c\u00e1c nh\u00e0 nghi\u00ean c\u1ee9u \u0111\u00e3 ph\u00e1t tri\u1ec3n nh\u1eefng thu\u1eadt to\u00e1n gi\u00fap cho Gi\u1ea3i t\u00edch Fourier d\u1ec5 \u1ee9ng d\u1ee5ng h\u01a1n, nh\u01b0 trong l\u0129nh v\u1ef1c \u0111\u1ecba ch\u1ea5n h\u1ecdc. Trong s\u1ed1 \u0111\u00f3 c\u00f3 nh\u1eefng d\u1ea1ng s\u00f3ng t\u00edn hi\u1ec7u c\u00f3 th\u1ec3 thay th\u1ebf s\u00f3ng h\u00ecnh sin do nh\u00e0 \u0111\u1ecba v\u1eadt l\u00ed Jean Morlet t\u1ea1i Trung t\u00e2m Nghi\u00ean c\u1ee9u Khoa h\u1ecdc Qu\u1ed1c gia Ph\u00e1p (CNRS), Marseilles, ph\u00e1t minh ra v\u00e0o n\u0103m 1981. \u00d4ng g\u1ecdi ch\u00fang l\u00e0 ondelettes<\/em> \u2013 hay wavelets trong ti\u1ebfng Anh (t\u1ea1m d\u1ecbch s\u00f3ng nh\u1ecf).<\/p>\n

Meyer \u0111\u00e3 t\u00ecnh c\u1edd \u201cch\u1ea1m tr\u00e1n\u201d v\u1edbi wavelet c\u1ee7a Morlet v\u00e0o n\u0103m 1982 khi \u0111\u1ee9ng \u0111\u1ee3i b\u00ean chi\u1ebfc m\u00e1y photocopy \u1edf Tr\u01b0\u1eddng B\u00e1ch khoa (\u00c9cole Polytechnique), Paris, n\u01a1i \u00f4ng l\u00e0m vi\u1ec7c l\u00fac b\u1ea5y gi\u1edd. M\u1ed9t \u0111\u1ed3ng nghi\u1ec7p c\u1ee7a \u00f4ng \u0111ang ch\u1ee5p b\u00e0i b\u00e1o v\u1ec1 wavelet c\u1ee7a Morlet v\u00e0 c\u1ea3 hai li\u1ec1n b\u1eadp v\u00e0o ch\u1ee7 \u0111\u1ec1 n\u00e0y. Meyer, v\u1ed1n l\u00e0 m\u1ed9t nh\u00e0 nghi\u00ean c\u1ee9u trong l\u0129nh v\u1ef1c t\u00edch ph\u00e2n h\u00e0m, \u0111\u00e3 say m\u00ea \u0111\u1ebfn n\u1ed7i \u00f4ng b\u1eaft ngay chuy\u1ebfn t\u00e0u \u0111\u1ea7u ti\u00ean t\u1edbi Marseilles \u0111\u1ec3 n\u00f3i chuy\u1ec7n v\u1edbi Morlet v\u00e0 c\u00e1c \u0111\u1ed3ng nghi\u1ec7p c\u1ee7a \u00f4ng. “N\u00f3 gi\u1ed1ng nh\u01b0 m\u1ed9t c\u00e2u chuy\u1ec7n c\u1ed5 t\u00edch”, Meyer k\u1ec3 trong m\u1ed9t cu\u1ed9c ph\u1ecfng v\u1ea5n n\u0103m 2011. “T\u00f4i c\u1ea3m th\u1ea5y cu\u1ed1i c\u00f9ng \u0111\u00e3 t\u00ecm \u0111\u01b0\u1ee3c nh\u00e0 c\u1ee7a m\u00ecnh.”<\/p>\n

N\u0103m 1986, Meyer \u0111\u00e3 t\u1ea1o ra lo\u1ea1t wavelet \u0111\u1ea7u ti\u00ean v\u00e0 trong nh\u1eefng n\u0103m ti\u1ebfp theo, khi l\u00e0m vi\u1ec7c \u1edf \u0110\u1ea1i h\u1ecdc Paris Dauphine, \u00f4ng tr\u1edf th\u00e0nh t\u00e2m \u0111i\u1ec3m c\u1ee7a m\u1ed9t m\u1ea1ng l\u01b0\u1edbi c\u00e1c nh\u00e0 to\u00e1n h\u1ecdc, c\u00e1c k\u0129 s\u01b0, nh\u00e0 v\u1eadt l\u00ed v\u00e0 nh\u00e0 khoa h\u1ecdc m\u00e1y t\u00ednh, v\u00e0 d\u01b0\u1eddng nh\u01b0 c\u1ee9 m\u1ed7i tu\u1ea7n h\u1ecd l\u1ea1i c\u00f3 m\u1ed9t ph\u00e1t minh m\u1edbi, Morel nh\u1edb l\u1ea1i.<\/p>\n

\u201c\u00d4ng trao \u0111\u1ed5i v\u1edbi nh\u1eefng ng\u01b0\u1eddi th\u1eadm ch\u00ed kh\u00f4ng n\u00f3i c\u00f9ng ng\u00f4n ng\u1eef to\u00e1n h\u1ecdc,\u201d Morel k\u1ec3. \u201cT\u1ea5t c\u1ea3 nh\u1eefng ng\u01b0\u1eddi n\u00e0y \u0111\u1ec1u c\u00f3 nh\u1eefng m\u1ea3nh gh\u00e9p c\u1ee7a b\u1ee9c tranh.”<\/p>\n

M\u1ed9t l\u00fd thuy\u1ebft \u0111\u1eb9p \u0111\u1ebd, r\u00f5 r\u00e0ng, ph\u1ed5 qu\u00e1t \u0111\u00e3 xu\u1ea5t hi\u1ec7n, v\u1eeba bao h\u00e0m v\u1eeba c\u1ea3i thi\u1ec7n nh\u1eefng c\u00f4ng c\u1ee5 gi\u00fap cho Gi\u1ea3i t\u00edch Fourier tr\u1edf n\u00ean th\u1ef1c ti\u1ec5n h\u01a1n. Th\u00ed d\u1ee5, c\u00f4ng tr\u00ecnh c\u1ee7a Meyer cho th\u1ea5y c\u00e1c c\u00f4ng c\u1ee5 \u0111\u01b0\u1ee3c ph\u00e1t minh \u0111\u1ec3 ph\u1ee5c v\u1ee5 vi\u1ec7c x\u1eed l\u00fd t\u00edn hi\u1ec7u c\u0169ng c\u00f3 th\u1ec3 d\u00f9ng \u0111\u1ec3 n\u00e9n d\u1eef li\u1ec7u, Morel n\u00f3i th\u00eam.<\/p>\n<\/blockquote>\n

http:\/\/tiasang.com.vn\/-khoa-hoc-cong-nghe\/Nguoi-dan-dau-cach-mang-wavelet%E2%80%9D-doat-giai-Abel-10547<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Jean-Michel Morel, nh\u00e0 to\u00e1n h\u1ecdc \u1ee9ng d\u1ee5ng v\u00e0 l\u00e0 \u0111\u1ed3ng nghi\u1ec7p c\u1ee7a Meyer t\u1ea1i tr\u01b0\u1eddng \u00c9cole Normale Sup\u00e9rieure Paris-Saclay, n\u00f3i, \u201cKh\u00f4ng c\u00f3 nhi\u1ec1u v\u00ed d\u1ee5 v\u1ec1 nh\u1eefng kh\u00e1m ph\u00e1 to\u00e1n h\u1ecdc \u1ea3nh h\u01b0\u1edfng tr\u1ef1c ti\u1ebfp \u0111\u1ebfn x\u00e3 h\u1ed9i l\u1edbn nh\u01b0<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"quote","meta":{"_mi_skip_tracking":false},"categories":[330],"tags":[420,419,417,418],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/p8jhJx-99","_links":{"self":[{"href":"https:\/\/rosetta.vn\/short\/wp-json\/wp\/v2\/posts\/567"}],"collection":[{"href":"https:\/\/rosetta.vn\/short\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/rosetta.vn\/short\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/rosetta.vn\/short\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/rosetta.vn\/short\/wp-json\/wp\/v2\/comments?post=567"}],"version-history":[{"count":0,"href":"https:\/\/rosetta.vn\/short\/wp-json\/wp\/v2\/posts\/567\/revisions"}],"wp:attachment":[{"href":"https:\/\/rosetta.vn\/short\/wp-json\/wp\/v2\/media?parent=567"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rosetta.vn\/short\/wp-json\/wp\/v2\/categories?post=567"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rosetta.vn\/short\/wp-json\/wp\/v2\/tags?post=567"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}