5, given the probability model as shown in table 4-9, the real value label of the sequence A1A1A3A2A3A1 is obtained.
Solution: By the know,
P (A1) =0.2, P (A2) =0.3, P (A3) =0.5
FX (0) =0,FX (1) =0.2, FX (2) =0.5, FX (3) =1.0, U (0) =1, L (0) =0
Because X (AI) =i, so x (A1) =1,x (A2) =2,x (A3) =3
by formula, L (n) =l (n-1) + (U (n-1)-L (n-1)) Fx (xn-1)
U (n) =l (n-1) + (U (n-1)-L (n-1)) Fx (xn)
When the A1 first appears, there are:
L (1) =l (0) + (U (0)-L (0)) Fx (0) =0
U (1) =l (0) + (U (0)-L (0)) Fx (1) =0.2
When A1 appears for the second time, there are:
L (2) =l (1) + (U (1)-L (1)) Fx (0) =0
U (2) =l (1) + (U (1)-L (1)) Fx (1) =0.04
When the A3 appears for the third time, there are:
L (3) =l (2) + (U (2)-L (2)) Fx (2) =0.02
U (3) =l (2) + (U (2)-L (2)) Fx (3) =0.04
When the A2 appears for the fourth time, there are:
L (4) =l (3) + (U (3)-L (3)) Fx (1) =0.024
U (4) =l (3) + (U (3)-L (3)) Fx (2) =0.03
When the A3 appears for the fifth time, there are:
L (5) =l (4) + (U (4)-L (4)) Fx (2) =0.027
U (5) =l (4) + (U (4)-L (4)) Fx (3) =0.03
When the A1 appears for the sixth time, there are:
L (6) =l (5) + (U (5)-L (5)) Fx (0) =0.027
U (6) =l (5) + (U (5)-L (5)) Fx (1) =0.0276
Therefore, the real value tag of the sequence A1A1A3A2A3A1 is: T (113231) = (L (6) + U (6))/2=0.0273;
6, for the probability model given in table 4-9, a sequence with a length of 10 labeled 0.63215699 is decoded.
Solution: The F (x1) =0.2,f (x2) =0.5,f (x3) =1 can be known by Table 4-9.
First assume L (0) =0,u (0) =1.
1. t*= (0.63215699-0)/(1-0) =0.63215699
FX (2) =0.5<= t*<= FX (3) =1
L (1) = L (0) + (U (0)-L (0)) Fx (2) =0.5
U (1) = L (0) + (U (0)-L (0)) Fx (3) =1
So the first character is A3
2. t*= (0.63215699-0.5)/(1-0.5) =0.26431398
FX (1) =0.2<= t*<= FX (2) =0.5
L (2) = L (1) + (U (1)-L (1)) Fx (1) =0.6
U (2) = L (1) + (U (1)-L (1)) Fx (2) =0.75
So the second character is A2
3. t*= (0.63215699-0.6)/(0.75-0.6) =0.21437993
FX (1) =0.2<= t*<= FX (2) =0.5
L (3) = L (2) + (U (2)-L (2) Fx (1) =0.63
U (3) = L (2) + (U (2)-L (2)) Fx (2) =0.635
So the third character is A2
4. t*= (0.63215699-0.63)/(0.635-0.63) =0.431398
FX (1) =0.2<= t*<= FX (2) =0.5
L (4) = L (3) + (U (3)-L (3)) Fx (1) =0.631
U (4) = L (3) + (U (3)-L (3)) Fx2) =0.6325
So the fourth character is A2
5. t*= (0.63215699-0.631)/(0.6325-0.631) =0.77132667
FX (2) =0.5<= t*<= FX (3) =1
L (5) = L (4) + (U (4)-L (4)) Fx (2) =0.63175
U (5) = L (4) + (U (4)-L (4)) Fx (3) =0.6325
So the fifth character is A3
6. t*= (0.63215699-0.63175)/(0.6325-0.63175) =0.5426533
FX (2) =0.5<= t*<= FX (3) =1
L (6) = L (5) + (U (5)-L (5)) Fx (2) =0.632125
U (6) = L (5) + (U (5)-L (5)) Fx (3) =0.6325
So the sixth character is A3
7. t*= (0.63215699-0.632125)/(0.6325-0.632125) =0.04265333
FX (k) =0<= t*<= FX (1) =0.2
L (7) = L (6) + (U (6)-L (6)) Fx (0) =0.632125
U (7) = L (6) + (U (6)-L (6)) Fx (1) =0.632275
So the seventh character is A1
8. t*= (0.63215699-0.632125)/(0. 632125-0.632275) =0.21326667
FX (1) =0.2<= t*<= FX (2) =0.5
L (8) = L (7) + (U (7)-L (7)) Fx (1) =0.632155
U (8) = L (7) + (U (7)-L (7)) Fx (5) =0.6322
So the eighth character is A2
9. t*= (0.63215699-0.632155)/(0.6322-0.632155) =0.04422222
FX (0) =0<= t*<= FX (1) =0.2
L (9) = L (8) + (U (8)-L (8)) Fx (0) =0.632155
U (9) = L (8) + (U (8)-L (8)) Fx (1) =0.632164
So the nineth character is A1
t*= (0.63215699-0.632155)/(0.632164-0.632155) =0.22111111
FX (1) =0.2<= t*<= FX (2) =0.5
L (Ten) = L (9) + (U (9)-L (9)) Fx (1) =0.6321568
U (Ten) = L (9) + (U (9)-L (9)) Fx (2) =0.6321595
So the tenth character is A2
Therefore, a sequence with a label value of 0.63215699 for a length of 10 decodes the sequence to A3A2A2A2A3A3A1A2A1A2
Fourth time assignment