PRUNING STRATEGIES IN THE ISIP DECODER

• Beam pruning
  • Separate beam at each level in search hierarchy

  • Prune away path at level l if path score q(l,t) satisfies
    q(l,t) < q_max(l,t) + b(l)

  • Independent control over beam thresholds allows optimal settings

• Maximum Active Phone Model Instance (MAPMI) pruning
  • Sets upper limit on active model instances at each frame

  • Directly controls memory requirements

• Issues
  • How to find the best settings for maximum speed at no
    performance degradation?

  • How do these heuristics interact?