1. PHNG PHP PHN TCH TING NI THEO CC C TRNG 1.1. Cc phng php trch chn c tnh Phn ny s gii thiu hai phng php c s dng rng ri trong cc h thngnhndnghinti tnhtoncc h sMFCC(Mel Scale Frequency Cepstral Coefficients) v h s PLP (Perceptual Linear Prediction). Hai k thut x l ting ni RASTA (RelAtive SpecTral) v CMS (Cepstral Mean Subtraction) cng c gii thiu. y l hai k thut loi b nhiu hay c s dng c bit l trong pht m c nhiu nhiu nh cc cu thu m qua in thoi. 1.1.1. Phng php tnh h s MFCCHnh 2.1 miu t cc bc tnh ton h s MFCC.Nhn mnh tn hiu (pre-emphasis).Trong bc x l u tin ny, tn hiu c a qua mt b lc s:1( ) 1pre preH z a z +Trong preal h s nhn mnh, thng c gi tr l 0,9700002861. B lc c tc dng tng cng tn hiu ti tn s cao (trn 1KHz) vi hai l do chnh: Ging ni c s suy gim khong 20dB/decade khi ln tn s cao do c im sinh l ca h thng pht m ca con ngi. Bc x l ny s tng cng tn hiu ln mt gi tr gn 20dB/decade khc phc s suy gim ny, H thng thnh gic ca con ngi nhy cm hn vi vng tn s cao, bc x l ny nhn mnh vng tn s cao, tr gip cho qu trnh m hnh ho m thanh sau ny ca h thng nhn dng.1Hnh1- 1. Cc bc x l ca phng php tnh ton h s MFCC.To khung tn hiu (framing). Tn hiu ting ni lun lun bin thin theo thi gian, tuy nhin, trong khong thi gian khong 10-20ms, tn hiu ting ni c coi l tng i n nh. Do , tn hiu thng c chia thnh cc khung kch thc 20-30 ms vi vng gi ln nhau khong 10-15 ms. Lm ca s (frame windowing). Ca s Hamming thng c p dng cho mi khung tn hiu gim s tc ng ca vic chia khung tn hiu:'2 ( 1){0.54 0.46cos( )}1n nns sN Trong , N l s mu d liu (sample) ca ca s.DFT(DiscreteFourierTransform).Ti bcny, vi mi khungtn hiu, bin i Fourier c p dng chuyn tn hiu v min tn s. Cng vic tnh ton c thc hin bng thut ton FFT (Fast Fourier Transform). Lc theo thang tn s Mel (Mel-frequency bandpass filter). Cc b lc s c p dng lc cc tn hiu theo cc gii tn s khc nhau. Phn ng ca tai ngi vi cc thnh phn ca tn s l khng tuyn tnh. S khc nhau v tn s vng tn s thp (> 1;while( (j >= m)&& (m >= 2) ){j-=m;m>>=1;} // whilej+=m;} // for} // ScrAmble//**************************************************void ButterFlies(long numPoints,int logN,int dir, struct _complex *f){double angle;17_complex w,wp,temp;long i,j,k,offset;long N, halfN;double wtemp;N=1;for(k=0;k < logN;k++){halfN=N;N= 3).3.1.4.3 Kh nng p dng HTK cho ting VitTrong vic gn nhn ng mV HTK c th hun luyn cc HMM khng cn nhn ng m nn vi nhng corpus d liu ting ni cha c gn nhn c th dng HTK tin x l vic gn nhn. C th l: Xc nh cc tp m t gn nhn Xy dng transcription cho cc cu ni Xy dng t in pht m t tp cc m t Xy dng h nhn dng li ni lin tc Sdnghnhndngvcctranscriptiongnnhn cho cc cu nitrongcorpus(forcealignment)mbochnhxc v s lng m t v th t trc sau ca tng m t. Chnh li khong thi gian pht m ca cc m t c xc nh bc trc bng tay cho chun xc.Nhn ng m rt quan trng trong nghin cu nhn dng li ni. Vic nghin cu cc c trng ca m t, ca thanh iu trong ng m lin tc u cn n nhn ng m. y l mt cng vic vt v, i hi chnh xc cao. Nu c cng c tin x l th s tit kim thi gian, mt nhiu cng sc.98ng dng trong cc h nhn dng li ni lin tc, b t vng nhVi b t vng nh, c th dng HTK xy dng h nhn dng li ni vi chnh xc cao, thi gian gii m khng ng k nn c th p dng trong thc t.3.2. M hnh lai ghp ANN/HMM3.2.1. H thng nhn dng dng HMM lin tcTrong h thng nhn dng dng HMM lin tc, xc sut pht x quan st bj(ot) l mt hm mt xc sut c xy dng trn c s cc hm mt xc sut Gauss. Hm ny bao gm mt hoc nhiu cc dng (stream), mi dng c th c mt hoc nhiu thnh phn trn bao gm cc hm mt xc sut Gauss. Cu trc nhiu dng cho php h thng m hnh ho nhiu dng thng tin khc nhau. Thng thng s lng dng ti a l 4 dng. Cng thc tng qut ca hm pht x quan stotti trng thijc biu din nh sau: 1 1( ) ( ; ; )sjsMSj t jsm st jsm jsmm sb o c o 1 1 ] NTrong Mjsl s thnh phn trn (mixture) ti trng thijca dng (stream) s, cjsm l trng s ca thnh phn th m v (.; ; ) N l hm xc sut Gauss vi cc tham s v . 11( ) ( )21( ; ; )(2 )o ono e NTrong , n l kch thc ca quan st o,sl trng s ca dng stream s cho php h thng tp trung hn vo mt dng d liu no v thng c gi tr l 1. Mi mt m hnh Markov n tng ng vi mt n v nhn dng ca c bn ca h thng. n v nhn dng c bn c th l t, m v hay bn m tit. Mi m hnh gm nhiu trng thi, trong c mt trng thi khi u v mt trng thi kt thc l cc trng thi c bit khng pht sinh quan st (non-emitting).Qutrnhhunluyncthchinbngphngthchunluyn nhng (embedded). Vi mi mt pht m, h thng s tm tp cha phin m 99chnh t ca pht m , sau n s tra cu trong t in pht m ca mi t tm ra c dy cc m v tng ng vi pht m. Mt m hnh Markov n ln s c xy dng bng cch ni cc m hnh Markov n ca cc m v vovi nhau. Sauthuttonhunluynforward-backwardscp dng vi m hnh Markov n ny. Vi thut ton hun luyn nhng, cc m hnh c ghp li vi nhau to thnh mt m hnh Markov n ln, trong vi mi m hnh nh ca cc m v c hai trng thi c bit l trng thi khi u v trng thi kt thc. Hai trng thi ny khng sinh cc quan st. Cng thc tnh cc xc sut tin v li khc so vi cc cng thc tnh ton c trnh by trong phn trc. Trong cc cng thc di y, k hiu (q) trn k t biu th m hnh Markov n th q trong m hnh ln. Cc xc sut tin ( )jt l xc sut ca dy quan st o1... ot ti thi im t trng thi j c c khi to nh sau:Vi trng thi u tin (Enter) trong m hnh: ) 1 () (1q1, nu q=1) 1 (1) 1 (11) 1 ( qNqqa trng hp cn liVi cc trng thi c sinh ra quan st( ) ( ) ( )1 1(1) ( )q q qj j ja b o Vi trng thi cui (Exit) trong m hnh 1( ) ( ) ( )2(1) (1)qq qNq q qN i iNia Nh vy m hnh HMM ln s lun bt u bng m hnh u tin. Cc gi tr khc ngoi cc gi tr trn c khi to bng 0. Vit> 1 ta c cc cng thc tnh ton quy nh sau:Vi trng thi khi u trong m hnh ,nu q=1(do m hnh lun bt u bng trng thi u tin ca m hnh u tin trong m hnh ln), trng hp cn liVi cc trng thi sinh quan st( )1( )qt 1( 1) ( 1) ( 1)1 1 1( 1) ( )q qq q qN Nt t a +01001( ) ( ) ( ) ( ) ( ) ( )1 12( ) ( ) ( 1) ( )qNq q q q q qj j i ij j tit t a t a b o 1 + 1 ]Vi trng thi cui trong m hnh 1( ) ( ) ( )2( ) ( )qq qNq q qN i iNit t a i vi trng hp ca xc sut li backward ( )it l xc sut ca dy quan st oT... ot ti thi im t trng thi i c khi to nh sau: Vi trng thi cui trong m hnh ) () (TqNq 1,nu q=Q 1 1( 1) ( 1)( )q qq qN iNT a + ++ +, trng hp cn liVi cc trng thi sinh quan st( ) ( ) ( )( ) ( )q qq q qi iN NT a T Vi trng thi u1( ) ( ) ( ) ( )1 12( ) ( ) ( )qNq q q qj j t jjT a b o T Cc gi tr khc ngoi cc gi tr trn c khi to bng 0. Vi too/. Phn bn tri ca /kh/ s cho ta category /.pau>kh/ khi t khng ng u cu hoc sau mt khong ngh pause. Khi khngngsaucctkhctaccccategorytngng /oong>kh/, /oot>kh/, /ai>kh/, /a>kh/, /oon>kh/, ... Nu m v c chia lm ba phn, phn gia s khng ph thuc vo ng cnh hai bn, ch c hai phn hai bn s ph thuc vo cc m v ng cnh n. Mi m v s c xc nh kiu ph thuc ng cnh thng qua nh ngha s phn phn chia ca m v . Mng nron dng c hun luyn gm nhiu lp, thng thng l ba lp. S lng nt u vo ph thuc vo kch thc vector c tnh ph ca mi khung tn hiu. V d vector c tnh ph gm 12 h t MFCC cng vi gi tr nng lng v gi tr delta ca cc gi tr trn to thnh 26 gi tr i vi mi khung tn hiu. Ngoi ra bn khung tn hiu ln cn khung tn hiu chnh: -60,-30, +30, +60ms cng c dng to thnh mt vector 130 c 103tnh ph ng vi mi khung tn hiu. Nu vy mng ANN s c 130 nt u vo. S lng nt thuc lp n thng c chn l 200 nt. Tuy nhin cha c ti liu no xut phng php dng xc nh s lng nt n mng ANN hot ng tt nht. S lng nt thuc lp n cng ln th qu trnh hc ca mng ANN cng lu. Thng thng s lng nt thuc lp n c chn gn vi s lng nt u ra ca mng ANN. S lng nt ra ca mng ANN ph thuc vo s lng category ca h thng. Qu trnh hun luyn mng nron c thc hin vi tng pht m dng th tc truyn ngc sai s. Vi mi pht m, thng tin nhn thi gian trong c s d liu ting ni cho ta cc khong thi gian thuc v m v cn hun luyn. Nh vy vi mi category cc khong thi gian dnh cho chng c xc nh trong mi pht m. Cc thng tin ny c dng hun luyn cho mng ANN.Qu trnh hun luyn mng ANN c tin hnh trn nhiu vng lp. Ph thuc vo s lng category, s lng cc category c buc, cu trc mng nron, kch thc d liu hun luyn, h s hc m mng nron c th hi t sau mt s ln lp.Mt tham s quan trng trong qu trnh hun luyn mng ANN l h s hc(learningrate). Tuynhingitr nycthiuchnhtutheotng mng ANN v tu theo kch thc d liu hun luyn. Nu h s hc ln, h thng s nhanh chng tin ti im cc tr, tuy nhin ngc li mng kh tip cn gn nht c n im cc tr. Nu h s hc nh, qu trnh hun luyn s lu mi ti c im cc tr nhng ngc li h thng c th tin gn ti im cc tr nhiu hn.3.2.3. H thng nhn dng dng HMM/ANNMng ANN c u im ni bt l kh nng phn lp. Tuy nhin khi p dng vo h thng nhn dng ting ni, mng ANN c mt nhc im l khng thch hp vi cc tn hiu ting ni di, bin thin theo thi gian. Do vyccnhnghincuthnghimhthngnhndnglai ghpgia mng nron v m hnh Markov n (HMM/ANN) vi mc ch hn ch nhc im ca hai phng php ANN v HMM, ng thi tn dng hai u im ca hai phng php ny: kh nng phn lp ca mng nron v kh nng m hnh ho thng tin thi gian ca m hnh Markov n.104Ckhnhiukintrcmnglai ghpHMM/ANNcxut, trong thng dng nht l kin trc dng mng MLP lm xc sut pht x quan st trong cc h thng mng lai ghp. Phn sau y s trnh by v kin trc mng lai ghp ny. 3.2.3.1 Cu trc mng lai ghpim khc bit chnh ca mng lai ghp HMM/ANN so vi cc m hnh Markov thng thng l hm bj(k) khng phi hm mt xc sut m l gi tr xc sut u ra ca mng ANN.Hnh di y miu t quan h gia cc m hnh HMM v mng nron ANN. Mi nt ra ca mng ANN tng ng vi mt trng thi ca m hnh HMM. Trng thi ca m v /oo/ trong hai t bn v mt c chung nhau mt nt ra ca mng ANN.Hnh3-44- M hnh mng lai ghp HMM/ANN3.2.3.2 Hun luyn mng HMM/ANNMnglai ghpHMM/ANNchunluynbnghunluynnhng (embedded).Tng ng vi mi pht m,cc m hnh Markov n ca cc n v nhn dng trong pht m c ni ghp li vi nhau to thnh mt mhnhHMMln. Thut tonforward-backwardcpdngiu chnh cc tham s ca cc m hnh ln ny. Cc gi tr output ca mng ANN c dng lm xc sut pht x quan st ca mi trng thi trong m hnh. 105Trong mi vng lp ca hun luyn forward-backward, thut ton Viterbi cpdngtmradycctrngthi tt nht trongmhnh HMM ln tng ng vi pht m dng hun luyn. T dy trng thi ny, ti mi thi im tng ng vi mt khung thi gian tn hiu ting ni, ta s c gi tr output ca mng ANN. Nt output tng ng vi trng thi hin ti c gi tr l 1, cc nt output khc c gi tr 0. T cc gi tr output ny, mng ANN c hun luyn li bng th tc truyn ngc sai s. Hnh sau m t qu trnh hun luyn mng HMM/ANN.Hnh3-45-Hun luyn mng lai ghp HMM/ANN.Phng php hun luyn nh trn, c th c p dng hiu qu hun luyn mng lai ghp HMM/ANN nu d liu dng hun luyn l ln. Phng php trn c nhc im l ti mi thi im, chng ta phi chn mt category 106c xc sut l 1, cc category cn li c xc sut l 0. iu ny khng hon ton chnh xc v mt khung tn hiu, do nh hng ca ng cnh xung quanh, c th mang mt phn c tnh ph ca cc khung tn hiu ln cn. Mt phng php hn ch nhc im ny l dng xc sut xut hin ti trng thi hin thi lm gi tr output ca mng ANN. Cc gi tr output ny c dng hun luyn mng ANN bng th tc truyn ngc sai s. Cc gi tr ny mm (soft) hn l gi tr 0 v 1. Kt qu thc nghim cho thy phng php ny tng chnh xc nhn dng ca h thng.Cc xc sut dng lm gi tr output ca mng ANN l t(i) = P(qt = Si |O,) l xc sut m hnh trng thi Si vo thi im t. Cng thc tnh xc sut ny chnh l cng thc c s dng trong thut ton forward-backward:t(i)=1( ,) ( ) ( ) ( ) ( )() ( ) ( ) ( )t it t t tNt tiP q S Oi i i iP O P Oi i 1i N, 1 t T3.2.4. Nhn dng3.2.4.1 Xy dng mng tMng t (word network) c dng nh ngha mt ng php, mi lin h th t gia cc t c nhn dng bi h thng. Mt tp nh ngha mng t cha mt danh sch cc nt biu din cc t v mt danh sch cc cung biu din chuyn dch gia cc t. Cc chuyn dch ny c th c cc xc sut gn lin vi n, v d cc xc sut ca m hnh ngn ng bigram. V d di y l mt mng t ca mt h thng nhn dng mi ch s lin tc v nh ngha ng php ca n.Hnh 6.14 - S ng php ca h thng nhn dng mi ch s lin tci vi cc h thng nhn dng c s lng t vng ln v trung bnh, nh ngha ng php ca h thng thng ch n thun l cu trc vng t mthaisilchnsil107(wordloop), c ngha l bt k mt t no trong b t in ca h thng u c th theo sau t bt k khc trong t in.3.2.4.2 M hnh ngn ng N-gramHnh3- 46- S mng word-loop vi cc xc sut bigram.Sau khi mng t c xy dng xong, cc thng tin ca m hnh ngn ng c tch hp vo mng t. Mt mng t ca mt h thng nhn dng lin tc l cu trc vng t word-loop, trong cc t c t song song vi nhau v cc ng u vng loop-back cho php bt k mt t no cng c th ng sau t kia. Cu trc ny c dng ph bin trong nhiu h thng nhn dng nh h thng nhn dng c chnh t. Cc xc sut bigram vo mi cung ni gia hai t. Trong Hnh 2.13 l s mt mng word-loop gm bn t, cc xc sut bigram P(wi/wj)c gn vo mi cung loop-back gia cc t, ngha l gia mt cp t bt k u cn c mt xc sut bigram tng ng.3.2.4.3 S dng mng t trong h thng nhn dng Khi mng t c np vo trong h thng nhn dng, mt t in phin m ca h thng s c dng to ra mt mng tng ng bao gm cc n v nhn dng c bn ca h thng, cc m n hoc cc m ba. Tu thuc vo cu hnh ca h thng m cc m ba c th l cc m ba gii ni t hay m ba lin t. Mt t c th c nhiu phin m, khi s c nhiu nhnh ca mng mi nhnh tng ng vi mi phin m ca t. Mng ny c gi l mng HMM. Nh vy ta c th thy mt cu trc ba mc ca mt mng dng nhn dng: mc t, mc m hnh v mc trng thi. Hnh 6.16 m t 108cu trc ny ca h thng nhn dng. Trong hnh ny cc hnh ovan biu th cc t, hnh vung biu din mt nhn kt thc mt t (word end).Hnh3-47- Cu trc ba lp ca mng t nhn dngMng dng nhn dng cui cng bao gm cc trng thi v cc cung ni chng vi nhau.Cc cung trong mt m hnh HMM chnh l xc sut chuyn trng thi c xc nh bi cc tham s ca HMM. Cc cung gia cc m hnh c xc sut tng ng nhau, cc cung gia cc t c xc sut c xc nh bi m hnh ngn ng. 3.2.4.4 Gii mNhimvcaqutrnhgii mltmramt ngi trongmng HMM c xc sut ln nht. thc hin cng vic ny mt thut ton tng tthut tonViterbi cdng, gi lthut tonchuynthbi (Token Passing). Gi thit mi trng thi j ca mt m hnh HMM ti thi im t gi mt th bi cha xc sut bn phn ( )jt . Xc sut ny l xc sut ca quan st t o1tiotvi m hnh ti trng thijv thi im t. Ti mi trng thiic nhiu r nhnh, thut ton s lm nh sau: Chuyn mt bn sao ca th bi ti trng thi i ti tt c cc trng thi j m c lin kt vi trng thi i, tng log xc sut ca bn sao: log[ ] log[( ( )]ij j ta b o + Tnh ton tt c cc th bi v s xo ht cc th bi, ch gi li th bi tt nht.109Mi mt th bi di chuyn trong mng u duy tr mt vt trn ng i ca n. S lng thng tin lu trn vt ph thuc vo yu cu ca h thng, thng thng ch dy cc t l c lu li. Thut ton chuyn th bi//Khi ng

// Chuyn th biFor t=1 to Tdo// T l s khung tn hiu ca pht mFor all trng thi i do ;For all trng thi i do ;End for// Dng

Trong hnh di yta thy trng thi 3 c nhn nhiu th bi t cc trng thi 1 v 2 v t chnh bn thn n. Sau ch c mt th bi duy nht c gi li.321+ p 2 3+ p 3 3+ p 1 3Hnh3-48- Minh ha thut ton chuyn th bi.Mt mng ln c nhiu nt th cng vic tm kim s rt lu v tn thi gian. Mt gii php nhm gim c hiu qu vic tnh ton l ch cho php 110cc th bi m c c hi l mt trong cc th bi tt nht mi c tn ti. C ch ny gi l ct ta (pruning).Ti mi bc cc th bi m c gi tr xc sut nm ngoi khong gi tr cho php so vi th bi c xc sut cao nht s b xo i. Khong gi tr cho php (beam-width) c iu chnh bi dung ho gia yu t tc v hiu qu ca thut ton tm kim.Kt thc qu trnh tm kim vi mi pht m ta nhn c mt dy cc t vi xc sut cao nht l kt qu nhn dng. 3.3. So snh hai phng php nhn dng CD-HMMv HMM/ANNPhng php nhn dng dng HMM hin l phng php ph bin nht dng trong nhn dng ting ni. Cng vi HMM, mng nron nhn to ANN cng c p dng vo trong nhn dng ting ni kt hp vi HMM thnh mng lai ghp HMM/ANN. Phn ny trnh by so snh gia hai phng php nhndng: phngphp dngHMMlin tc CD-HMM(Continuous Density Hidden Markov Model) v phng php dng mng lai ghp HMM/ANN. C s d liu Qutrnhhunluynmnglai ghpHMM/ANNcbt ubng hunluynmngANN. TrongqutrnhhunluynmngANN, dliu tng ng vi tng n v nhn dng c a vo hun luyn. Do cc thng tin v nhn thi gian l bt buc phi sn c trong c s d liu h thng tm ra cc khung tn hiu tng ng vi cc n v nhn dng, t tnh ton cc vector c tnh ph. V l do ny, c s d liu dng hun luyn mng HMM/ANN cn phi c cc thng tin v nhn thi gian, hay ni cch khc d liu dng hun luyn mng HMM/ANN phi c gn nhn. Khc vi phng php trc, hun luyn h thng dng CD-HMM c bt u bng cch khi to cc tham s ca cc m hnh Markov n. Nu cc thng tin nhn thi gian sn c, h thng s khi to cc tham s ca m hnh Markov n theo d liu ng vi tng m hnh. Cn nu cc nhn thi gian l khng sn c, cc m hnh Markov n ca c h thng s c khi to vi cng mt tham s, cch khi to ny gi l khi to phng (flat start). Hun luyn nhng sau ny s iu chnh cc tham s ca ca tng m hnh. V l 111do ny m h thng dng CD-HMM khng bt buc cc pht m trong c s d liu cn phi c gn nhn bng tay. n v nhn dng c bnTrong h thng nhn dng dng mng lai ghp HMM/ANN n v nhn dng c bn lun l category, l mt phn ca m v. Do c tnh bin thin ting ni theo thi gian, trong khong thi gian tn ti ca mt m v, cc c tnhphcamv binthintlcbt uti khi kt thcmt mv. Khong thi gian m cc c tnh ph tng i tnh, tc l c th dng c cho hun luyn mng ANN ch l mt phn ca m v: phn bn tri ca m v, ni m v chu nh hng ca ng cnh phi, phn gia ca m v khng chu nh hng ca ng cnh v phn bn phi ca m v, chu nh hng ca ng cnh phi. Nu n v nhn dng c di ln hn c s dng, mng ANN s c hun luyn vi d liu c khc nhau nhiu vi cng mt n v nhn dng v do vy hiu qu hot ng s b hn ch.Vi h thng nhn dng dng CD-HMM, n v nhn dng c bn kh linh hot: c th l m tit, bn m tit hoc m v. Vi cc h thng nhn dng nh, n v nhn dng c bn c th l cc t. Khi s lng cc trng thi trong m hnh c th c th c iu chnh nhiu hn, thng thng l ln 6 hoc 8 trng thi. Vi h thng nhn dng c kch thc t in ln, n v nhn dng c bn thng l m v hoc bn m tit, s trng thi trong m hnh khi c iu chnh nh hn, khong t 3-5 trng thi. m ng Trong h thng HMM/ANN, mng, k hiu l /uc/ (unvoiced clousure) c coi l mt n v nhn dng ring. Tuy nhin v nh hng ca n n ng cnh cc m v khc th chng li c xp chung vi n v nhn dng khong lng sil. V mt cc c tnh ph, khong yn lng silv m ng l tng t nhau bi v chng cng biu din mt khong yn lng. Hnh nh ca hai loi n v nhn dng ny trn biu ph ging nhau, u l mt khong trng nng lng. S khc nhau ch yu ca hai n v nhn dng ny l di. Trong m ng thng c di khong 30ms th khong yn lng c di thng xuyn ln hn 30ms. Hn na trong qu trnh trch chn c tnh ph ca mt 112khungtnhiu, cckhungtnhiulnggingcakhungtnhiuchnh (thng trong khong 60ms) cng tham gia vo vector c tnh ph. V vy c tnh ph ca hai n v nhn dng khi a vo mng ANN l c khc nhau do ng cnh xung quanh.Vi h thng dng CD-HMM, cc m ng khng c mt trong cc n v nhn dng c bn, chng c ghp vo cng vi m tc ng trc hoc ng sau n, tu thuc m tc l ph m u hay ph m cui. Thng thng vi n v nhn dng c bn l m v, m hnh Markov n ca mi m v gm ba trng thi. m ng c m hnh ho bi trng thi u v hai trng thi sau s m hnh ho m tc hoc l hai trng thi u s m hnh ho m tc v trng thi cui s m hnh ho m ng trong trng hp m ng ng sau m tc. V d sau y l cc n v nhn dng c bn ca t ba mt tng ng vi hai trng hp:o H thng HMM/ANN, m ng /uc/ c tch ra ring vi m tc: /uc/ /b/ /a/ /m/ /oo/ /t/ /uc/o HthngCD-HMM: mng/uc/ cgpvovi m tc: /uc/ /b/ -> /bb/, /t/ /uc/ -> /tt/: /bb/ /a/ /m/ /oo/ /tt/ Ph thuc ng cnh CD-HMM: Do c tnh ca ting ni, tt c cc h thng nhn dng u dng n v nhn dng l ph thuc ng cnh. tnh n ng cnh tri v ng cnh phi ca m v, CD-HMM dng m ba (triphone), trong mt m v c b sung thm ng cnh t m v c lp ng cnh tng ng. V d nh m v /a/ s c chuyn thnh m ba /b-a+n/ trong t bn, v khi y l n v nhn dng khc vi m v /a/ trong t n: /dd-a+n/. C hai loi m ba c phn bit: m ba gii ni t (word internal) v m ba lin t (cross-word). Trong m ba gii ni t, nh hng ca ng cnh c coi l ch c tc dng trong t , gia cc t vi nhau c coi l c ngn cch bi khong lng. Vi m ba lin t, nh hng ca ng cnh tnh n cc m v ca cc t lng ging. Loi m ba ny phn nh chnh xc nh hng ca ng cnh n cc m v, tuy nhin vi cch ny s lng cc m ba c th l rt ln. Vi ting Vit s lng cc m ba lin t c th ln ti hn 16 nghn 113m ba. Vi s lng ln nh vy, d liu hun luyn cn c l rt ln v vn thiu ht d liu hun luyn l kh trnh khi. V d sau y l cc m n v cc m ba ca pht m anh ni ting Vit h:Phin m chnh t: anh noi tieeng vieet ham v: sil ea ngz sil n o i t ie ngz v ietc h a silm ba gii ni t: sil sil-ea+ngz ea-ngz+n ngz-n+o n-o+i o-i+t i-t+ie t-ie+ngz ie-ngz+sil sil-v+ietc v-ietc+h ietc-h+a h-a+sil silm ba lin t: sil ea+ngz ea-ngz sil n+o n-o+i o-i sil t+ie t-ie+ngz ie-ngz sil v+ietc v-ietc sil h+a h-a sil sil Trong h thng nhn dng HMM/ANN, mng ANN ch c th tin hnh phn lp vi mt phn ca m v, ni cc c tnh ph khng thay i nhiu. tnh n nh hng ca ng cnh n cc n v nhn dng m v c chia thnh nhiu n v nhn dng c bn hay gi l category. Mt m v c th c chia thnh 2 hoc 3 hoc hoc c khai bo l mt category ph thucphi. Nhvynv nhndngcbnphthucngcnhca HMM/ANN thc cht l m i (biphone) ch khng phi l m ba. Vi cch lm ny th s lng cc n v nhn dng c bn ca HMM/ANN khng ln nh trong trng hp ca CD-HMM. Vi ting Vit, nu b t in bao gm tt c cc t, th s lng category l khong 2147 category. Sau y l cc n v nhn dng ca h thng HMM/ANN tng ng vi pht m trn:m v: sil ea ngz sil n o i t ie ngz v ietc h a sil category: silngz easil sil silo ni iie tngz ngz To Sound CardM t chng trnh ngun bng ngn ng VC++count of written words=0;for each word in the text{if (count of written words > 128){szCustPara[0]=1;SetFilePointer(hFile,0,NULL, FILE_BEGIN);(*piFileSizeCounter)=0;count of written words=0;153} // ifcount of written words++;ConvertWordToRawData(word, pInt16, &lenInSamples);if(g_format==U_LAW_PCM_8KHZ_8BITS)RawToULaw(pInt16, lenInSamples, fs, lpOut, &lenOut);else if(g_format== A_LAW_PCM_8KHZ_8BITS)RawToALaw(pInt16, lenInSamples, fs, lpOut, &lenOut);if(g_format!=-1){WriteFile(hFile,(LPCVOID)lpOut,(DWORD)lenOut,&dwWritten,NULL);(*piFileSizeCounter)+=(int)dwWritten;} // if} // forUnmapViewOfFile(piFileSizeCounter);Khi gi hm EsiTtsProcess nu szCustPara[0]==1 th t liszCustPara[0]=0 && c ti u file#define DLLEXPORT extern "C" __declspec(dllexport)//szCustPara, iCPSize hin thi cha s dng//cha h tr A_LAW format.DLLEXPORT int EsiTtsSetEngine(int iFormat, int iLine, LPCSTR szCustPara, int iCPSize){if(iFormat==2)g_format=A_LAW_PCM_8KHZ_8BITS;else if(iFormat==3)g_format=U_LAW_PCM_8KHZ_8BITS;elseg_format=-1;g_line=iLine;return 0;} // EsiTtsSetEngine154//szCustPara, iCPSize hin thi cha s dng//cha h tr A_LAW format.DLLEXPORT int EsiTtsInitialize(int index,LPCSTR szCustPara,int iCPSize){// c tham s ng k, np d liu voice vnvoice.dat trong th mc \\dbvoice\\khanh_hn_48// ....//return 0;} // EsiTtsInitialize//szCustPara, iCPSize hin thi cha s dng//cha h tr A_LAW format.DLLEXPORT int EsiTtsUninitialize(int index, LPCSTR szCustPara, int iCPSize){// ...return 0;} // EsiTtsUninitialize//szCustPara, iCPSize hin thi cha s dng//cha h tr A_LAW format.DLLEXPORT int EsiTtsProcess(int index, HANDLE hFile,LPCSTR szInputText, int iInputSize, HANDLE hTtsFileSizePtrMapping, LPCSTR szCustPara, int iCPSize){extern __int16 *pInt16;extern LPBYTE lpOut;extern int fs;// 11025(KHz), 8000(KHz)...int lenInSamples,lenOut;DWORD dwWritten;int *piFileSizeCounter=(int*)MapViewOfFile(hTtsFileSizePtrMapping,FILE_MAP_ALL_ACCESS, 0, 0, 0);if(piFileSizeCounter==NULL){155MessageBox(NULL,"MapViewOfFile","Error!",MB_ICONERROR);return ERROR_CODE;} // iffor each word in the text{ConvertWordToRawData(word, pInt16, &lenInSamples);if(g_format==U_LAW_PCM_8KHZ_8BITS)RawToULaw(pInt16, lenInSamples, fs, lpOut, &lenOut);else if(g_format== A_LAW_PCM_8KHZ_8BITS)RawToALaw(pInt16, lenInSamples, fs, lpOut, &lenOut);if(g_format!=-1){WriteFile(hFile,(LPCVOID)lpOut,(DWORD)lenOut,&dwWritten,NULL);(*piFileSizeCounter)+=(int)dwWritten;} // if} // forUnmapViewOfFile(piFileSizeCounter);return 0;} // EsiTtsProcess5.2. Cng thoi 3i 5.2.1. iu khin voice menu CallflowNh cch tng tc thng thng vi cc ng dng thng qua thc n (trong cc giao din vn bn, ho), cc ng dng tr li t ng bng ting ni trn in thoi cng giao tip vi ngi dng thng qua cu trc menu bng ting ni thun tu hoc kt hp vi bn phm s hn ch trn in thoi. Tuy nhin, cch x l cc menu ny kh khn hn nhiu so vi cch x l menu truyn thng. Voice menu c cc c im sau:- Phikim sot thi gian ngi dng la chn chc nng trn menu (nu qu di phi hu b chc nng ny hoc h thng ngng phc v cuc gi ny).156- Kim sot s kin nhn phm trong khi vn phi ra cc li nhc bng ting ni trn menu item. Vic ny gy ra kh khn trong khi ng b ho cc s kin ring r l nhn phm, pht hoc ngng pht ting ni trn in thoi.- Kim sot s ln truy cp khng hp l, nu vt qu mt gii hn ln h thng s ngng phc v.Hnh5-50- H thng thao tc dc v duyt th thoi.5.2.2. X l ng thi nhiu cuc gi x l c nhiu cuc gi ng thi (mt card Diaglogic loi nh c t 4-12 cng IO, cho php x l ng thi 4-12 cuc gi) h thng s c thit k thnh cc lung,tin trnh con chy song song vi nhau.Cc tin trnh ny c ng b ho vi nhau theo cc s kin, chng hn:- ng b ho cc s kin ngi dng (phm bm, thi gian)- ng b ho cc s kin m thanh, kt thc bnh thng hoc do h thng p t (do qu thi gian quy nh khi truy cp mt chc nng ca h thng).1575.2.3. Pht ting ni trn in thoiTing ni trn in thoi c tn s thp, t 4KHz - 8KHz. Trn ng truyn, tn hiu c th b nh hng bi nhiu, ngoi ra vi cc tn hiu in thoi di ng ngi ta cn p dng cc k thut m ho ting ni ti u ho di tn. Do vy ni chung cht lng m thoi km hn so vi cht lng m thanh trn card m thanh. nghe c ting ni r hn, nh truyn thng h thng dng mt ging pht thanh vin n.Module tch hp Vnvoice vo h thng vit dng th vin DLL vi cc hm API nh sau:BOOL WINAPI AddClientString(LPSTR st);char** WINAPI GetSentence(int &countSentence,BOOL &bVietnamese);void WINAPI SetFontAsDefault(char *);void WINAPI FreeTTSResult(__int16* &pTTSSample)BOOL WINAPI SentenceToRaw(char** sentence, int countSentence, __int16* &pTTSSample, int &countTTSSample)Cch tch hp c thc hin qua cc li gi hm:Input: B nh buff cha vn bn text ting Vit hoc ting Anh.Output: B m cha sng m tng hp c pTTSSamplecountTTSSample s mu tn hiu tng hp cGii m sau minh ha cch thc hin li gi hm:DllAddClientString(buff);BOOL bVietnamese;char **sentence;__int16 *pTTSSample;int countTTSSample;while(1){bVietnamese=TRUE;sentence=GetSentence(bVietnamese, countSentence);if(sentence==NULL)break;// Chuyen doi sang raw158if(bVietnamese==TRUE){pTTS=NULL;DllSentenceToRaw(sentence, countSentence,pTTSSample, countTTSSample);// do some thing// ...DllFreeTTSResult(pTTSSample);}// ifelse{// using English TTS Engine}// else}// whileCch tch hp trn l cho m hnh khng ng b, v vy kh d dng thc hin ghp ni giao din gia cc thnh phn ca h thng v c lp li.5.2.4. Lp trnh tch hp card Dialogic vo ng dngTuy rng cc chc nng cho x l in thoi v m thanh c tch hp sn trn card Dialogic, vic lp trnh x l card Dialogic kh phc tp do trn Dialogic tch hp rt nhiu chun. Lp trnh trn Dialogic c lin quan cht ch vi vic vn dng cc hm API ca th vin chun TAPI, lp trnh mc thp cho card m thanh ( y cng chnh l card Dialogic), chuyn i nh dng m thanh, iu khin cc s kin...Thu ting ni vo t telephone trong thi gian thc l khng d dng. Hin nhin rng khng th b nh lu tn hiu c ni vo lin tc. Trong h thng ny, chng ti s dng nhiu tnh cht su v h thng ca Windows, t chc d liu theo kiu b m vng m bo vic ng b d liu theo cc khung ting ni, mi on l 64 mu (xp x 8 mili giy nu thu ting vi tn s ly mu l 8KHz).S TT Tn card Hnh1591Dialogic D 4PCIPlug-in card - PCI, Cable - 64 Kbps2Dialogic D 120JCT-LSPlug-in card - PCI, Cable3Dialogic SingleSpan 240PCIPlug-in card - PCI, Cable - 1.544 Mbps4Dialogic D 80-PCIPlug-in card - PCI, Cable - 64 Kbps5Dialogic D 41EPCIPlug-in card - PCI, Cable - 64 KbpsBng5-1- Danh sch mt s card Dialogic.5.2.5. Mt s thut ngPBX- Private Board Exchange: tng i ni bPSTN - Public Switched Telephony Network: mng chuyn mchCTI- Computer Telephony Integrated: tch hp my tnh v in thoiTAPI- TelephonyApplicationProgrammingInterface (Microsoft API dnh cho cc ng dng CTI)DTMF - Dual tone multi-frequence: xung quay s a tnPort, Line: Ti nguyn iu khin mt cuc gi, mt h thng vi 8 port c th iu khin c 8 cuc gi ng thi. Trn mng thoi cc port ny c ng k theo nhm (dch v s trt), ngi s dng ch cn nhn mt s in thoi trong nhm. Mng in thoi s t ng trt sang port khc nu ng line ny ang bn.TTS Text-to-Speech: b tng hp ting ni.PSOLA pitch synchronous overlap add.TD-PSOLA Time domain pitch synchronous overlap add : cng chng ng b tuyn tnh tn s c bn F0 min thi gian:y l thut ton kinh in cho tng hp theo phng php ghp ni m c bn. Thut ton ny dng thay i tn s c bn F0, trng ca m gc.Text processing, text normalize: x l vn bn, chun ho vn bn.GSM Global system for mobile telecommunication protocol.160CELP Code Excited Linear Prediction. ASR -Automatic-speech-recognition: Nhn dng ting ni t ng.Speaker Dependent Recognition: h thng nhn dng ting ni cho mt hoc mt vi ngi ni xc nh. Cc h thng ny c th c lng t vng rt ln, nhng yu cu thi gian hun luyn lu.Speaker Independent Recognition: h thng nhn dng ting ni cho mt ngi ni bt k. Ni chung, nhng h thng ny hot ng tt cho b t vng nh, s ng m gia cc t l thp hoc trong mt ng cnh xc nh ca cc cu ni.Speaker verification Speaker recognition:nhn bit ngi gi da trn c trng ging ni ca ngi .VoiceXML Voice eXtensible Markup Language: mt ngn ng script vit cc ng dng v dch v Web vi tnh nng ting ni. Hip hi VoiceXML c khong hn 400 cng ty trn th gii tham gia.Voice Portal: cng ting ni hay cn gi l cng thoi.NLP Natural Language Processing: k thut x l ngn ng t nhin, trong cc h thng TTS, Voice Portal thng p dng cc k thut NLP phn on vn bn thnh cc cu, cu thnh cc t (ting Vit khng c ranh gii gia cc t mt cch r rng) v hiu cu (cu truy vn thng tin...).5.2.6. Tch hp in thoi v my tnhHin nay, Cng ngh Thng tin v Vin thng tr nn hi t, d nhn thy l cc my in thoi di ng cao cp vi tnh nng truy cp Web, gi e-mail.Ngc li, kh nng x l ca my tnh cng c th c s dng cho cc chuyn mch in thoi, nh cc tng i ni b PBX (xem ph lc 4) thng c xy dng vi cc ng CTI. Cc ng ny chuyn cc thng ip t cc chuyn mch n my tnh th hin s thay i trng thi ca cuc gi nh pht hin cuc gi mi, kt thc cuc gi, v ngc li ng lin kt CTI s chuyn cc lnh t my tnh ti chuyn mch thc hin cc thao tc nh tr li, chuyn cuc ging CTI c th l ng RS-232, Ethernet161Cc h thng CTI cho php truy cp c s d liu qua ng in thoi trong mt h thng d liu hp nht nh fax, e-mail, voice-mail5.2.6.1 Chun lp trnh TAPIL mt tp hp cc hm API cho phplp trnh iu khin, qun l mi kt ni thngtingiamytnhvinthoi. TAPIgmccAPIcholine (ng dy) v phone (in thoi).Chun cho line: m phng ng line, cc ng dng TAPI c th dng nhiu device hn s line hin c ca PC, chng hn mt ng dng TAPI c th cung cp cc tnh nng nh nhn in thoi, fax. Nu PC ch c mt line vo th TAPI s chia x ng truyn gia cc chun thit b ny.Cch chia x ti nguyn s c thc hin thng qua mt hng i.Hnh5-51- Kin trc phn tng TAPIChun cho phone: N cho php m phng chc nng in thoi trn my tnh, vi sound card v microphone c th m phng tt c cc chc nng ca in thoi c nh. TAPI 3.0 tng thch vi kin trc WOSA (Windows Open Services Architcture)5.2.6.2 DialogicIntel Dialogic l mt trong nhng cng ty cung cp cc gii php CTI ln nht. Cc h sn phm ca Dialogic rt a dng, bao gm cc gii php cho cc ng dng nh ti ng dng ln vi hng trm cng, thit b c th ghp ni vi PC hoc my ch vi cc ng dng tch hp sn nh tng hp, nhn dng ting ni, truyn v nhn fax, x l Internet phone.162GiaodincaInter Dialogicbaogmcacloi: D4/PCI, D/120JCTTM, D/240JCT-T1TM ...C nhiu loi card Dialogic vi tnh nng khc nhau nh:+ card PCI 32 bit, PCI 64bit.+ card c chc nng c th ng thi pht m v ghi m (song cng) hoc ch thc hin c mt chc nng ti mt thi im.+ card tch hp sn cc dch v Fax, Internet phone, nhn dng ting ni..H thng cng thoi 3i ch s dng card D4/PCI l loi card PCI 32bit, khng th pht v thu ng thi, khng tch hp sn cc dch v Fax, Internet phone, nhn dng ting ni...5.2.6.3 Chun VoiceXMLVoiceXML l mt HTML cho cc ng dng tch hp in thoi. N che giu chi tit v nn in thoi cung cp kh nng pht trin nhanh cc ng dng ting ni, truyn thng a dng. N s dng cng ngh nhn dng ting ni v DTMF nh cc u vo v dng cng ngh tng hp ting ni cung cp u ra.VoiceXML c cc c im sau: ng dng logic tch bit vi giao din ting ni v th cc doanh nghip c th tn dng li cc u t v cng ngh Web v c s h tng. Cc doanh nghip c th to cc giao din ting ni trong khi vn c gia c cc chc iu khin trn ng dng logic. VoiceXML l mt chun cho php lp trnh vin vit mt ln v chy ng dng ti mi nn. VoiceXML c lp vi ting ni v mi trng in thoi nn. VoiceXML l mt ngn ng script n gin. Lp trnh vin c th pht trin ng dng d dng, khng phi bn tm v phc tp ca nnCcbduyt htrchunVoiceXML(gi lVoiceXMLbrowser) l thnh phn chnh din gii v iu khin cc hi thoi. N cng iu khin ting ni v cc ti nguyn thoi. Thnh phn thoi chu trch nhim d DTMF, thit lp cuc gi, chuyn v kt thc cuc gi.163 sinh ting ni u ra, VoiceXML s dng cc b tng hp ting ni TTS. Cc module ASR c s dng nhn dng ting ni ngi dng v chuyn sang dng text cho b duyt VoiceXML5.2.6.4 Voice PortalCc h thng Voice Portal cho php truy cp thng tin trn Web site bng ting ni ngha l chng cung cp giao din cho ngi dng in thoi truy cp v ly thng tin t Web site.Mt h thng Voice Portal c tch hp c phn cng v phn mm nh my ch, mng in thoi, card tch hp CTI v cc cng ngh tng hp, nhn dng ting ni, cc cng thng tin Web (Web portal).1646. C S D LIU NG M CHO NHN DNG V TNG HP TING VIT 6.1. Gii thiuPhn ny s gii thiu v tin trnh xy dng cc c s d liu (CSDL) phn tch tham s m hc, gn nhn n v ting ni cho ting Vit. CSDL ting ni ny c xy dng nhm p ng vic nghin cu ting Vit. D liu c ghi m bng my phn tch m chuyn dng CSL ca Kay vi nh dng 16 bit, mono, 16 bit intel PCM (LSB, MSB) thu mi trng t nhin vphngbmcaTrungtmNgmhcVinNgnnghc. Vic nghin cu ting ni, phi da trn mt ngun d liu ln v ting ni bao qut cc nhhng nhgiitnh,tuitc,kiuvn bn,kiuc.CSDL c la chn phc v cho vic nghin cu ting Vit tp trung vo 2 mc ch chnh 1) xy dng mt h thng d liu cho tng hp ting Vit 2) xy dng h thng d liu cho nhn dng lnh, c chnh t v bc u cho phn lp, nhn dng ngi ni. CSDL ting ni l c s h tng cho c vic nhn dng v tng hp ting ni. Trong h thng nhn dng, d liu ting ni c s dng lm cc tp hun luyn cho cc b nhn dng xc nh cc tham s ca cc m hnh nhndng, v dnhcchstrngscanrontrongmhnhmng Nron, hay xc sut xut hin ca cc trng thi, xc sut chuyn i trng thi trong m hnh Markov n. Vi mt d liu ting ni ln v thut ton hp l hiu qu nhn dng s t c kt qu ti u. Hn na, d liu ting ni s cn c s dng kim tra hiu qu lm vic ca h thng, qua ta c th nh gi kh nng nhn dng ca h thng cng nh so snh cc h thng khc nhau.i vi cc h thng tng hp, d liu ting ni s cung cp mt h thng cc n v m c bn (ph m u, nguyn m, vn) c th xy dng thnh t, on hay cu c th pht m.Nguyn tc chung khi xy dng mt d liu ting ni l d liu s cha ng cc t v cu thng xuyn s dng nht. Ngoi ra, d liu bao gm ln cc bin th c th h tr to ra ngn ng ni t nhin v linh hot. Do 165, mi d liu ting ni bao hm mt trong nhng mc tiu sau: bao qut v mt ng ngha, bao qut v mt c php, bao qut v mt ngn iu v bao qut v mt t. Tuy nhin m bo c ng thi nhng mc tiu trn l rt kh. Thng thng, cc t, cc cu v cc on c gng c la chn sao cho cha ng tt c cc ph m, vn, phong ph v ng cnh (context) v a dng v t vng, ng ngha v c php, y v thanh iu.C s d liu c chia thnh ba phn:- D liu dng hun luyn. Bao gm 60% tng s d liu ca h c s d liu.- D liu pht trin. Bao gm 20% tng s d liu ca h c s d liu. D liu ny c dng hon thin, iu chnh cc thng s ca h thng nhn dng trong qu trnh pht trin h thng nhn dng.- D liu kim tra: Bao gm 20% tng s d liu ca h c s d liu. D liu ny c dng nh gi chnh xc nhn dng ca h thng. cho khch quan ging ngi ni trong tp d liu pht trin v d liu kim tra khng c mt trong tp d liu hun luyn. iu ny trnh h thng nhn dng vi ging ni m n c hun luyn trc.6.2. Ghi m cho CSDL ghi m v qun l tn hiu c ghi, chng ti s dng thit b CSL ca Kay vi phn mm chy trn h iu hnh Window9x v WindowsNT, vi microShure. Tnhiusclymu16bit, mono, tnslymu 11025.Hnh6-52. Ph ting ni ca cu166Mc tiu ca CSDL l ghi m trong nhiu iu kin mi trng khc nhau, tuy nhin giai on u vic thu m c thc hin ti phng thu v mi trng vn phng.Giai on sau chng ti tin hnh thu m mi trng bnh thng. Cc tn hiu thu c c phn tch v s dng, qua c nh gi v chnh sa nu cn thit c th phc v cho nhng ln thu tip theo.Cng vic ghi m tng chng l n gin nhng li l mt cng on tn nhiu thi gian nht trong vic xy dng CSDL.Nht l vic tin hnh thu m 300 ging cho nhn dng lnh. m bo s lng d liu chng ti phi thu m nhng mi trng khc nhau thm ch mi trng c nhiu nhiu v ting n (trng hc, k tc x, c quan). Mi ngi c mt bng t gm 193 m theo ng yu cu chm ri, r rng khong cch gia cc m u nhau. Chng ti mt khong 2-3 pht hng dn v 4-5 pht c. 300 ngi vi nhng cch c khc nhau (nhanh, chm, to, nh, ngng, ln ting n) gy rt nhiu kh khn cho chng ti trong qu trnh phn tch d liu. Kinh nghim cho chng ti nhn thy rng vic la chn d liu khng nn qu ln trong mt phin ghi m trnh khng gy mt mi cho nhng ngi thc hin thu m, bng t cn phi c b tr mt cch khoa hc: nhng m tit gn m khng nn xp gn nhau, nhng m tit c ri c xp cng vi nhau, nhng m c lin xp cng vi nhau v cn c nhng hng dn c th trc khi thu m. Cho ngi c c th mt vi ln sau mi tin hnh thu m. Nu ngi c c sai, nhm m tit no th c li m tit , nht l i vi nhng m tit c m c gn ging nhau (ng, ph, c, ch, nh, th; b, x, d, , t, v, ng-kp, ng-ghp, g-kp, g-ghp). i vi nhn dng chnh t v tng hp th qu trnh thu m c vt v hn v ch tin hnh thu vi mt ngi tuy nhin khi lng d liu cn c tng i ln tng cng hn 800 cu cho c nhn dng v tng hp. Vic nh gi d liu thu c thc hin thng qua vic nh gi cht lng mi trng thu, m lng v xem xt t s tn hiu trn nhiu. Chng ti nhn thy rng cc kt qu thu l tng i tt v chp nhn c.1676.3. D liu cho nhn dng ting Vit6.3.1. Nhn dng lnh c c mt CSDL ting ni, trc tin chng ta phi c mt d liu vn bn dnh cho ghi m sao cho tho mn yu cu t ra. Trong nhn dng lnh chng ti c yu cu ngi ni c mt bng t gm 193 m tit ri rc c chia thnh cc b lnh khc nhau chng hn b lnh ca IE (Internet Explorer). Nhng lnh ny c chia thnh hai kiu c.T hp t: yu cu c linGhi Trang ngm nhIn Ti li trangTu chn in Xem m ngunXem in Ton mn hnhGi ni dung Trang a thchGi a ch Gi thThuc tnh c thNgng kt ni mngTu chnXo Tr gipCopy T in lnhDn Ghi tpChn ht Ghi fileTm kimm tit thnh phn: yu cu c riGhi NiIn MngTm TKim inTu LnhChn ThcHt HinXem ng MGi DngNi TinDung nga TipCh Li168Thuc FileTnh TpTrang ThotNgm anh ThchTi TrLi GipM NgngNgun KtTon HnhMnS v ch ci: yu cu c ri, r rngb skhng sumtbyhai byba tmbn chn nm mib lnhchm europhy tngtriu hiutrm tchnghn thngchc mtt mi lal vitlinh namnhm ngb ch cinguyn m m n r te go h ht lt169 rcha rtu chi xph m ngnb dic khca lchngcu kpd ghp nhdi trn d pdi pl phquy qur vt vt xth xnngnhch ci nh l t hp m: yu cu c lint e r i c rtg kp e lg ghp e mng ghp e nng kp e ri di t xi ngn ch nngx nng ch nhx nh d ch x d dii c lt d ii c rch d trn Viclachnngi ni cnglmt trongnhngvnquantrng. Nhng ch tiu quan trng trong vic la chn ngi ni l gii tnh, tui tc, 170v tr a l, trnh hc vn, sc khe. Nhng ngi c bng t ca ti phn ln l cc sinh vin ca cc trng i hc trn a bn H Ni. Vic la chn p ng nhng yu cu sau:- Gii tnh: Nhm m bo s cn i v gii tnh, chng ti c gng la chn sao cho m bo s cn bng nam n. Tng s ngi c la chn l 300, tuy nhin s ging nam l 120 v n l 180.- Tui: Tui c nh hng nhiu n cht lng ting ni, ting ni ca con ngi s n nh mt cch tng i trong la tui trng thnh t 18 n 40 tui. i vi CSDL, tui c la chn t 18 n 50.- V tr a l: Vic p ng tt c cc ging ca tng a phng l cha th thc hin vi iu kin hin ti, do bc u s ngi la chn ch l nhng ngi min Bc, m cha chn nhng ngi ni ging t Thanh Ha tr vo.Vi mi ngi chng ti yu cu c bng t nh trnh by trn, thi gian cho mt ngi c khong 4-5 pht. H thng nhn dng lnh thu 300 ging khc nhau vi nh dng11025Hz, 16 bit, mono trong mi trng bnh thng c nhiu. D liu cnhgi tngitt. Saukhi thu d liu chng titin hnh hiu chnh d liu theo cc bc sau: - Vi mi ngi c chng ti lu vo mt file ring sau khi lc b nhiu.- Sau chng ti ct ri tng m tit (nu l c ri) v t hp m tit (nu l c lin) v mi m li c ghi thnh mt file con.- Trong danh sch cc file con ca mt ngi c chng ti to mt file Listword lit k tt c tn, s lng cc file d liu ca mt ngi c.Nh vy vi 300 ngi c chng ti s c 300 file, mi file ngi c cha 193 n v. Tng cng chng ti s c 57900 n v m.-Saukhi dliucxl chngti tinhnhhunluynbngcc phng php khc nhau hiu chnh tham s cho n khi t yu cu. 6.3.2. Nhn dng chnh ti vi nhn dng chnh t ph thuc ngi ni vi tp t vng l ton b cc m tit ting Vit v kh nng kt hp c th c hn 19.000 m tit 171nhng ch c hn 6000 m tit c ngha c lit k trong t in. u tin chng ti to khong 800 cu text. Cc cu text cn m bo:Tnh m hcS lng m tit trong cu khng nhiu qu ti a l 40 m tit trong mt cu.S c on trong cu.Hintngngniu: thanhiu, trng, tnhdngngt hi (pause).Hin tng ngn ng: cc cu text c y cc loi cu hi, cm thn, mnh lnh..., y cc loi t: t kp, t ly, tnh t, trng t, danh t, ng tPhn b ca cc n v cn c vo:Tn s xut hin ln nht ca mt m tit trong cu.Tn s xut hin ln nht ca mt vn trong cu.Tn s xut hin ln nht ca mt ph m u trong cu.Tn s xut hin ln nht ca mt nguyn m (n, i, ba) trong cu.Phn b thanh iu trong cu.Yu cu c th- S c on ca mi cu (