1. Connected Word Recognition
Speech Recognition 40833

4. The connected word recognition problem
Problem definition:
Given a fluently spoken sequence of words, how can we determine the optimum match in terms of a concatenation of word reference patterns?

5. To solve the connected word recognition problem, we must resolve the following problems

6. connected word recognition

7. connected word recognition

8. connected word recognition

10. connected word recognition

11. connected word recognition
The alternative algorithms:
Two-level dynamic programming approach
Level building approach
One-stage approach and subsequent generalizations

12. Two-level dynamic programming algorithm

13. Two-level dynamic programming algorithm

15. Two-level dynamic programming algorithm

17. Two-level dynamic programming algorithm
Computation cost of the two-level DP algorithm is:
The required storage of the range reduced algorithm is:
e.g., for M=300, N=40, V=10, R=5
C=1,320,000 grid points
And S=6600 locations for D(b,e)

18. Two-level algorithm Example

19. Two-level algorithm Example

20. Two-level algorithm Example

21. Level Building algorithm

24. Best distance at level l to frame m
Reference pattern index
Backpointer to the best ending frame at previous level

26. Advantage of LB: Disadvantage of LB:
By performing computation in levels (i.e., a word at a time) and by doing appropriate minimization within levels, much of 2-level DP approach computations are avoided
Disadvantage of LB:
The computation level is level synchronous, not time synchronous; that is, we can go back to a given test frame at many levels

27. Example: we are interested in 4 levels solution only

30. Computation
Of The
Level Building
Algorithm

31. Implementation Aspects of Level Building
Beginning range reduction – MT
Global range reduction – ε
Test pattern ending range – δEND
Reference pattern uncertainty regions – δR1 , δR2

36. Integration of a Grammar Network

38. 1 I 5
ONE 9
BOOKS 13
OLD 2
WANT 6 A 10
COAT 3
NEED 7 AN 11
COATS 4
THREE 8
BOOK 12
NEW

39. Current
Words
Predecessor
State
Uses
Level
Levels 2 I 1 3
WANT 4
NEED 5
THREE 6 A 7 AN 8
ONE
NEW
OLD 9 9*
BOOK, COAT 10
7,8,9
BOOKS, COATS 11

42. One-pass or One-state algorithm
Also known as frame-synchronous level building (FSLB) method
For each test frame the accumulated distance is calculated as:

43. One-pass or One-state algorithm

44. One-pass or One-state algorithm

45. One-pass or One-state algorithm
The problem is that no mechanism is provided for
Controlling the resulting string path.
For incorporating the level, we write:

46. Incorporating multiple
candidate strings

49. Using HMM in level building

54. Segmental k-means Training Algorithm