failed nbest 4-gram

[glynpu]

	test-clean
baseline no rescore	4.18
4-gram lm n-best rescore	4.27(n=1000)
4-gram lm lattice rescore	3.67

format of followig three-line score
no-rescore
n-best rescore: n =1000
lattice-rescore

epoch 30, no average:
output-beam-size 8:
2021-05-29 21:16:00,188 INFO [common.py:380] [test-clean] %WER 4.24% [2228 / 52576, 309 ins, 172 del, 1747 sub ]
2021-05-29 21:25:43,312 INFO [common.py:380] [test-clean] %WER 4.37% [2299 / 52576, 649 ins, 74 del, 1576 sub ]
2021-05-29 21:11:19,485 INFO [common.py:380] [test-clean] %WER 3.82% [2009 / 52576, 397 ins, 102 del, 1510 sub ]

output-beam-size 20:
2021-05-29 21:30:45,323 INFO [common.py:380] [test-clean] %WER 4.61% [2422 / 52576, 765 ins, 70 del, 1587 sub ]


with avg of epoch(5-19)
2021-05-29 10:56:33,837 INFO [common.py:380] [test-clean] %WER 4.18% [2196 / 52576, 253 ins, 204 del, 1739 sub ]
2021-05-29 11:05:42,011 INFO [common.py:380] [test-clean] %WER 4.27% [2247 / 52576, 613 ins, 83 del, 1551 sub ]
2021-05-29 11:02:28,304 INFO [common.py:380] [test-clean] %WER 3.67% [1932 / 52576, 333 ins, 126 del, 1473 sub ]

with avg of epoch(4-19)
2021-05-29 11:09:49,398 INFO [common.py:380] [test-clean] %WER 4.17% [2191 / 52576, 255 ins, 187 del, 1749 sub ]
2021-05-29 11:19:14,436 INFO [common.py:380] [test-clean] %WER 4.17% [2191 / 52576, 590 ins, 78 del, 1523 sub ]
2021-05-29 11:15:56,589 INFO [common.py:380] [test-clean] %WER 3.64% [1915 / 52576, 330 ins, 108 del, 1477 sub ]

lattice rescore with averaging different models

avg(4-29)
2021-05-29 11:45:22,937 INFO [common.py:380] [test-clean] %WER 3.61% [1899 / 52576, 328 ins, 101 del, 1470 sub ]
avg(4-30)
2021-05-29 11:53:21,700 INFO [common.py:380] [test-clean] %WER 3.59% [1887 / 52576, 331 ins, 101 del, 1455 sub ]
avg(1-30)
2021-05-29 12:08:18,920 INFO [common.py:380] [test-clean] %WER 3.70% [1943 / 52576, 350 ins, 107 del, 1486 sub ]