File size: 63,025 Bytes
6fa4bc9
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
{
    "paper_id": "2020",
    "header": {
        "generated_with": "S2ORC 1.0.0",
        "date_generated": "2023-01-19T12:13:59.999764Z"
    },
    "title": "Vietnamese-English Translation with Transformer and Back Translation in VLSP 2020 Machine Translation Shared Task",
    "authors": [
        {
            "first": "L",
            "middle": [
                "E"
            ],
            "last": "Duc",
            "suffix": "",
            "affiliation": {
                "laboratory": "",
                "institution": "Hanoi University of Science and Technology",
                "location": {}
            },
            "email": ""
        },
        {
            "first": "Cuong",
            "middle": [],
            "last": "Nguyen",
            "suffix": "",
            "affiliation": {
                "laboratory": "",
                "institution": "Hanoi University of Science and Technology",
                "location": {}
            },
            "email": ""
        },
        {
            "first": "Thi",
            "middle": [
                "Thu"
            ],
            "last": "Trang",
            "suffix": "",
            "affiliation": {
                "laboratory": "",
                "institution": "Hanoi University of Science and Technology",
                "location": {}
            },
            "email": "trangntt@soict.hust.edu.vn"
        }
    ],
    "year": "",
    "venue": null,
    "identifiers": {},
    "abstract": "Transformers have been proven to be more effective for machine translation and many NLP tasks. However, those networks may not work well to low-resource translation tasks, such as the one for the English-Vietnamese language pair. Therefore, this paper aims to enhance the quality of the machine translation model by using the transformer model with a backtranslation technique. An intermediate translation system was built using the bilingual dataset as a training corpus. This system was then used with a large monolingual dataset to generate the back-translation data, which can be considered as augmented training data for the translation model. The experimental result on the IWSLT'15 English-Vietnamese test set showed that the system with back-translation outperforms about 2.4 BLEU points than the system with the only transformer. With the test set of the Machine Translation shared task in VLSP 2020, the proposed system with backtranslation was ranked as the first place with the highest score of human evaluation (1.55 points, compared to 1.33 points for second place). With the automatic evaluation, the system achieved a 32.1 BLEU score and a 0.50 TER score on VLSP 2020 Machine translation task test data.",
    "pdf_parse": {
        "paper_id": "2020",
        "_pdf_hash": "",
        "abstract": [
            {
                "text": "Transformers have been proven to be more effective for machine translation and many NLP tasks. However, those networks may not work well to low-resource translation tasks, such as the one for the English-Vietnamese language pair. Therefore, this paper aims to enhance the quality of the machine translation model by using the transformer model with a backtranslation technique. An intermediate translation system was built using the bilingual dataset as a training corpus. This system was then used with a large monolingual dataset to generate the back-translation data, which can be considered as augmented training data for the translation model. The experimental result on the IWSLT'15 English-Vietnamese test set showed that the system with back-translation outperforms about 2.4 BLEU points than the system with the only transformer. With the test set of the Machine Translation shared task in VLSP 2020, the proposed system with backtranslation was ranked as the first place with the highest score of human evaluation (1.55 points, compared to 1.33 points for second place). With the automatic evaluation, the system achieved a 32.1 BLEU score and a 0.50 TER score on VLSP 2020 Machine translation task test data.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Abstract",
                "sec_num": null
            }
        ],
        "body_text": [
            {
                "text": "The demand for translation from one language to another is increasing due to the explosion of the Internet and the exchange of information between various regions using different regional languages. Machine translation has long been a major problem in the field of Natural Language Processing (NLP). Neural Machine Translation (NMT) has recently been put into research and has made huge improvements to machine translation systems. Most NMT systems are based on an encoder-decoder architecture consists of two neural networks (Bahdanau et al., 2016; Luong et al., 2015) . The encoder compresses the source strings into a vector, used by the decoder to generate the target sequence. Sequenceto-sequence networks consist of two Recurrent Neural Networks (RNNs) and an attention mechanism has significant improvements compared to the traditional statistical machine translation approach.",
                "cite_spans": [
                    {
                        "start": 526,
                        "end": 549,
                        "text": "(Bahdanau et al., 2016;",
                        "ref_id": "BIBREF0"
                    },
                    {
                        "start": 550,
                        "end": 569,
                        "text": "Luong et al., 2015)",
                        "ref_id": "BIBREF7"
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Introduction",
                "sec_num": "1"
            },
            {
                "text": "To the best of our knowledge, transformer architecture networks have achieved the best results for many languages (Vaswani et al., 2017; Wang et al., 2019; Edunov et al., 2018) . Transformer is a network architecture based on a self-attention mechanism. Transformers are good at machine translation and many NLP tasks because they totally avoid recursion, by processing sentences as a whole and by learning relationships between words thanks to multi-head attention mechanisms and positional embeddings. Recent networks include a number of parameters and they mostly focus on high-resource language pairs data.",
                "cite_spans": [
                    {
                        "start": 114,
                        "end": 136,
                        "text": "(Vaswani et al., 2017;",
                        "ref_id": null
                    },
                    {
                        "start": 137,
                        "end": 155,
                        "text": "Wang et al., 2019;",
                        "ref_id": "BIBREF13"
                    },
                    {
                        "start": 156,
                        "end": 176,
                        "text": "Edunov et al., 2018)",
                        "ref_id": "BIBREF4"
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Introduction",
                "sec_num": "1"
            },
            {
                "text": "However, those networks may not work well to low-resource translation tasks such as English-Vietnamese. Preparing a good quality bilingual data set is quite difficult, while the amount of monolingual data is quite abundant and available online. That raises a basic idea of using this single language data source to enhance the quality of the machine translation model. Some approaches to solving this problem include creating a language model to improve the quality of the machine translation model (Sennrich et al., 2016) or using backtranslation.",
                "cite_spans": [
                    {
                        "start": 499,
                        "end": 522,
                        "text": "(Sennrich et al., 2016)",
                        "ref_id": "BIBREF8"
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Introduction",
                "sec_num": "1"
            },
            {
                "text": "In this paper, we propose a machine translation system participating in the Machine Translation Shared Task in VLSP 2020 (Thanh-Le et al., 2020) . The main translation model in this system is the transformer with back-translation. This technique can be considered semi-supervised learning, whose main purpose is data augmentation. Despite being simple, the back translation technique has achieved great improvements in both SMT (Bojar and Tamchyna) and NMT (Edunov et al., 2018) .",
                "cite_spans": [
                    {
                        "start": 121,
                        "end": 144,
                        "text": "(Thanh-Le et al., 2020)",
                        "ref_id": "BIBREF10"
                    },
                    {
                        "start": 457,
                        "end": 478,
                        "text": "(Edunov et al., 2018)",
                        "ref_id": "BIBREF4"
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Introduction",
                "sec_num": "1"
            },
            {
                "text": "The rest of this paper is organized as follows. Section 2 presents related works using encoderdecoder and back-translation architecture. Our methodology is presented in Section 3. The experiments are shown in Section 4 and Section 5. Finally, Section 6 concludes the paper and gives some perspectives for the work.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Introduction",
                "sec_num": "1"
            },
            {
                "text": "We build upon recent work on neural machine translation which is typically a neural network with an encoder/decoder architecture. The encoder represents information of the source sentence, while the decoder is a neural language model based on the output of the encoder. The parameters of both models are learned together to maximize the occurrence of target sentences with corresponding source sentences from a parallel corpus (Sutskever et al., 2014) . At inference, a target sentence is generated by left-to-right decoding. Different neural architectures have been proposed with the goal of improving the efficiency of the translation system. This includes recurrent networks (Sutskever et al., 2014; Bahdanau et al., 2016; Luong et al., 2015) , convolutional networks (Kalchbrenner et al., 2014; Gehring et al., 2017) and transformer networks (Vaswani et al., 2017) . Recent work is based on the attention mechanism in which the encoder generates a sequence of vectors for each target token, the decoder pays attention to the most relevant part of the source through the weights of the vectors encoder (Bahdanau et al., 2016; Luong et al., 2015) . Attention has been refined with self-attention and multi-head attention (Vaswani et al., 2017 ). The baseline model of our system is the transformer architecture (Vaswani et al., 2017) .",
                "cite_spans": [
                    {
                        "start": 427,
                        "end": 451,
                        "text": "(Sutskever et al., 2014)",
                        "ref_id": "BIBREF9"
                    },
                    {
                        "start": 678,
                        "end": 702,
                        "text": "(Sutskever et al., 2014;",
                        "ref_id": "BIBREF9"
                    },
                    {
                        "start": 703,
                        "end": 725,
                        "text": "Bahdanau et al., 2016;",
                        "ref_id": "BIBREF0"
                    },
                    {
                        "start": 726,
                        "end": 745,
                        "text": "Luong et al., 2015)",
                        "ref_id": "BIBREF7"
                    },
                    {
                        "start": 771,
                        "end": 798,
                        "text": "(Kalchbrenner et al., 2014;",
                        "ref_id": "BIBREF6"
                    },
                    {
                        "start": 799,
                        "end": 820,
                        "text": "Gehring et al., 2017)",
                        "ref_id": "BIBREF5"
                    },
                    {
                        "start": 846,
                        "end": 868,
                        "text": "(Vaswani et al., 2017)",
                        "ref_id": null
                    },
                    {
                        "start": 1105,
                        "end": 1128,
                        "text": "(Bahdanau et al., 2016;",
                        "ref_id": "BIBREF0"
                    },
                    {
                        "start": 1129,
                        "end": 1148,
                        "text": "Luong et al., 2015)",
                        "ref_id": "BIBREF7"
                    },
                    {
                        "start": 1223,
                        "end": 1244,
                        "text": "(Vaswani et al., 2017",
                        "ref_id": null
                    },
                    {
                        "start": 1313,
                        "end": 1335,
                        "text": "(Vaswani et al., 2017)",
                        "ref_id": null
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Related work",
                "sec_num": "2"
            },
            {
                "text": "The idea of back-translation has been suggested since statistical machine translation, where it was used for semi-supervised learning (Bojar and Tamchyna) or self-training (Vandeghinste, 2011). In the modern NMT study, (Sennrich et al., 2016) reported significant increases in terms of WMT and IWSLT shared tasks (Edunov et al., 2018) , while (Currey et al., 2017) reported similar findings on low resource conditions, suggesting that even poor translations can make progress.",
                "cite_spans": [
                    {
                        "start": 219,
                        "end": 242,
                        "text": "(Sennrich et al., 2016)",
                        "ref_id": "BIBREF8"
                    },
                    {
                        "start": 313,
                        "end": 334,
                        "text": "(Edunov et al., 2018)",
                        "ref_id": "BIBREF4"
                    },
                    {
                        "start": 343,
                        "end": 364,
                        "text": "(Currey et al., 2017)",
                        "ref_id": "BIBREF2"
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Related work",
                "sec_num": "2"
            },
            {
                "text": "Aforementioned, for the low-resource bilingual dataset like English-Vietnamese, we proposed to use the back-translation technique as an augmentation technique to build more data for the training corpus. Back-Translation can be considered as a semi-supervised learning technique. Firstly, an intermediate machine translation system is trained using existing parallel data. This system is used to translate the target to the source language. The result is a new parallel corpus in which the source side is a translation synthesizer while the target is the text is written by humans (monolingual dataset). Then, the synthesized parallel corpus is combined with the real text (bilingual dataset) to train the final system. Back-Translation does not need to change model architecture unlike using a language model. The basic idea to use the language model is scoring the candidate words proposed by the translation model at each time step or concatenating the hidden states of the language model and the decoder.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Our proposed system architecture",
                "sec_num": "3.1"
            },
            {
                "text": "Figure 1 illustrates our proposed system architecture. In this paper, we adopted Transformer as the main translation model. Both monolingual and bilingual datasets must be cleaned and preprocessed before feeding to the Transformer model, which will be presented in subsection 3.2.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Our proposed system architecture",
                "sec_num": "3.1"
            },
            {
                "text": "To build the final translation model, three main phases have to be performed:",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Our proposed system architecture",
                "sec_num": "3.1"
            },
            {
                "text": "\u2022 Phase 1: Training a Vietnamese-English translation model with transformer using the bilingual dataset.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Our proposed system architecture",
                "sec_num": "3.1"
            },
            {
                "text": "\u2022 Phase 2: Generating an extra bilingual dataset from the monolingual dataset using the Vietnamese-English translation model in the previous phase. During this phase, we used greedy decoding to speed up the data generation process because the monolingual data set was quite large.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Our proposed system architecture",
                "sec_num": "3.1"
            },
            {
                "text": "\u2022 Phase 3: Combining generated extra bilingual dataset with origin bilingual one and train the final Vietnamese-English translation model.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Our proposed system architecture",
                "sec_num": "3.1"
            },
            {
                "text": "We use the same transformer architecture for the English-Vietnamese or Vietnamese-English translation model. Detail description of this architecture is presented in Subsection 3.3. ",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Our proposed system architecture",
                "sec_num": "3.1"
            },
            {
                "text": "We received and only used two datasets from VLSP 2020 translation task (Thanh-Le et al., 2020) to develop our model. The monolingual dataset included about 20 million sentences crawled from a number of different e-newspapers. The bilingual database had about 4.14 million sentences from many different domains, presented in Table 1 .",
                "cite_spans": [],
                "ref_spans": [
                    {
                        "start": 324,
                        "end": 331,
                        "text": "Table 1",
                        "ref_id": "TABREF0"
                    }
                ],
                "eq_spans": [],
                "section": "VSLP 2020 Datasets",
                "sec_num": "3.2.1"
            },
            {
                "text": "The bilingual dataset was used to train both English-Vietnamese and Vietnamese-English model while the monolingual dataset was used to create the back-translation dataset. ",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "VSLP 2020 Datasets",
                "sec_num": "3.2.1"
            },
            {
                "text": "The bilingual dataset was manually labeled by VLSP organizers so the problems with low translation quality are few. Therefore, we only need to remove too long sentence pairs in this dataset. All sentences having more than 250 words were eliminated. Meanwhile, the monolingual dataset was crawled on the Internet. Therefore, this dataset had some problems in the raw text, e.g. too long sentences (due to the fault of the sentence tokenizer), non-Vietnamese language, HTML characters. We need a number of steps for data cleaning and preprocessing for this dataset. Some main steps were taken as follows.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Data cleaning and Pre-processing",
                "sec_num": "3.2.2"
            },
            {
                "text": "\u2022 Removing non-Vietnamese sentences: Filtering out sentences that are not in Vietnamese using a language detection model;",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Data cleaning and Pre-processing",
                "sec_num": "3.2.2"
            },
            {
                "text": "\u2022 Removing sentences that are too long or too short;",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Data cleaning and Pre-processing",
                "sec_num": "3.2.2"
            },
            {
                "text": "\u2022 Cleaning HTML characters and some special characters.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Data cleaning and Pre-processing",
                "sec_num": "3.2.2"
            },
            {
                "text": "After the data cleaning and pre-processing, the monolingual dataset had nearly 20 million remaining sentences, while the bilingual one had a total of 4.1 million sentence pairs. The data were cleaned, normalized, then lower-cased and tokenized using the Moses 1 tool. The data were learned a BPE set of 35,000 items using the Subword Neural Machine Translation toolkit 2 .",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Data cleaning and Pre-processing",
                "sec_num": "3.2.2"
            },
            {
                "text": "The core idea behind the Transformer model is selfattention, the ability to attend to different positions of the input sequence to compute a representation of that sequence. The transformer creates stacks of self-attention layers to build both encoder and decoder instead of RNNs or CNNs. This general architecture helps transformer model calculated in parallel, instead of a series like RNNs, and learn long-range dependencies. The transformer architecture is presented in Figure 2 . Without the recurrence or the convolution, the transformer encodes the positional information of each input token by a position encoding function.",
                "cite_spans": [],
                "ref_spans": [
                    {
                        "start": 474,
                        "end": 482,
                        "text": "Figure 2",
                        "ref_id": "FIGREF1"
                    }
                ],
                "eq_spans": [],
                "section": "The Transformer Model",
                "sec_num": "3.3"
            },
            {
                "text": "Thus the input of the bottom layer for each network can be expressed as Input = Embedding + P ositionalEncoding. The positional encoding is added on top of the actual embeddings of each word in a sentence. The encoder has several layers stacked together. Each layer consists of a multi-head self-attention mechanism and a position-wise fully connected feed-forward network. Multi-head self-attention mechanism help model can pay \"attention\" to many certain pieces of content of the input.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "The Transformer Model",
                "sec_num": "3.3"
            },
            {
                "text": "The decoder is also a stack of identical layers, each layer comprising three sub-layers. At the bottom is a masked multi-head self-attention, which ensures that the predictions for position i depend only on the known outputs at the positions less than i. In the middle is another multi-head attention which performs the attention over the encoder output. The top of the stack is a position-wise fully connected feed-forward sub-layer. The decoder output finally goes through a linear transform with softmax activation to produce the output probabilities.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "The Transformer Model",
                "sec_num": "3.3"
            },
            {
                "text": "Transformer setup. We use the Transformer model in PyTorch from the fairseq toolkit 3 . All experiments were based on the Big Transformer architecture with 6 blocks in the encoder and decoder. We used the same hyper-parameters for all experiments, word representations of size 1024, feed-forward layers with inner dimension 4096. We used 16 attention heads, and we average the checkpoints of the last ten epochs. Models were optimized with Adam optimization using \u03b2 1 = 0.9, \u03b2 2 = 0.98, and \u03b5 = 1e \u2212 8.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Experimental setup",
                "sec_num": "4.1"
            },
            {
                "text": "Back-translation set up. We run experiments on 2 GPU Tesla V100 and spent about 36 hours training the final model.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Experimental setup",
                "sec_num": "4.1"
            },
            {
                "text": "VLSP organizers provided two evaluation results for each model: (i) Automatic evaluation, and (ii) Human evaluation.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Automatic Evaluation and Human Evaluation",
                "sec_num": "4.2"
            },
            {
                "text": "In VLSP 2020, the automatic evaluation was used for reference, but not for the final decision for system ranking. The two metrics were BLEU and TER scores.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Automatic evaluation",
                "sec_num": "4.2.1"
            },
            {
                "text": "BLEU is a quality metric score for MT systems that attempts to measure the correspondence between a machine translation output and a human translation, as illustrated in Equation 1. The central idea behind BLEU is that the closer a machine translation is to a target human translation, the better it is. (1) Translation Edit Rate (TER) is a method to determine the amount of Post-Editing required for machine translation jobs. The automatic metric measures the number of actions required to edit a translated segment inline with one of the reference translations, as illustrated in Equation 2.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Automatic evaluation",
                "sec_num": "4.2.1"
            },
            {
                "text": "(2)",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "T ER = number of edits length of ref erence sentence",
                "sec_num": null
            },
            {
                "text": "Human evaluation is the main metrics for ranking participating systems. There were 5 experts who were professional Vietnamese-English translators or interpreters. Each subject was asked to rate all systems from 1 to 6 based on Adequacy and Fluency. The overall rank was calculated by using the TrueSkill algorithm. TrueSkill is a rating system among game players. It was developed by Microsoft Research and has been used on Xbox LIVE for ranking and matchmaking services. This system quantifies players' TRUE skill points by the Bayesian inference algorithm.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Human Evaluation",
                "sec_num": "4.2.2"
            },
            {
                "text": "To find out the role of back-translation, we did some experiments on the IWSLT'15 English-Vietnamese test set. This test set is used from Stanford NLP group and has 1268 pairs Vietnamese-English sentence. Table 2 presents the results of the systems that used and did not use the back-translation (the baseline model with the transformer only). The experimental result showed that the model with back translation outperforms to the baseline one about 2.4% in BLUE score. Table 3 . The final model that we submitted was our proposed system, which used Transformer and Back-Translation. Our system achieved a 32.10 BLEU score and a 0.5 TER score. According to the results of VLSP organizers, our BLEU score was at third and TER score is at second. However, the human evaluation of our system got the best result, which was 1.554. This led our system to be the first rank in the Machine Translation shared task in VLSP 2020.",
                "cite_spans": [],
                "ref_spans": [
                    {
                        "start": 205,
                        "end": 212,
                        "text": "Table 2",
                        "ref_id": "TABREF1"
                    },
                    {
                        "start": 470,
                        "end": 477,
                        "text": "Table 3",
                        "ref_id": "TABREF2"
                    }
                ],
                "eq_spans": [],
                "section": "Experiment for Back-Translation",
                "sec_num": "5.1"
            },
            {
                "text": "As in Table 3 , the automatic evaluation (BLEU) was on pair with human evaluation except in the case of our system. A possible reason was found that our system did not do casing recovery. The automatic evaluation metrics do consider casing, but the experts do not. ",
                "cite_spans": [],
                "ref_spans": [
                    {
                        "start": 6,
                        "end": 13,
                        "text": "Table 3",
                        "ref_id": "TABREF2"
                    }
                ],
                "eq_spans": [],
                "section": "Experiment for Back-Translation",
                "sec_num": "5.1"
            },
            {
                "text": "After having some observations on the outputs of the baseline and the system with back translation, we find that the model using back translation gave more natural results than the baseline one. For instance, as shown in the Table 4 by removing the duplicated pronounce \"h\u1ecd\" (them) in the output, model using back translation avoids repeating words and makes the sentence more natural. Input: they will go back home to celebrate tet together with their families.",
                "cite_spans": [],
                "ref_spans": [
                    {
                        "start": 225,
                        "end": 232,
                        "text": "Table 4",
                        "ref_id": "TABREF3"
                    }
                ],
                "eq_spans": [],
                "section": "Observations",
                "sec_num": "5.3"
            },
            {
                "text": "Baseline model: h\u1ecd s\u1ebd v\u1ec1 nh\u00e0 \u0111\u1ec3 \u0103n m\u1eebng t\u1ebft v\u1edbi gia \u0111\u00ecnh h\u1ecd.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Observations",
                "sec_num": "5.3"
            },
            {
                "text": "Baseline model + Back translation: h\u1ecd s\u1ebd tr\u1edf v\u1ec1 nh\u00e0 \u0111\u1ec3 \u0103n m\u1eebng t\u1ebft v\u1edbi gia \u0111\u00ecnh.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Observations",
                "sec_num": "5.3"
            },
            {
                "text": "With back translation, more suitable terms were selected in a specific context. As illustrated in Table 5, with the back translation mechanism, the \"characteristics\" word was translated into \"\u0111\u1eb7c \u0111i\u1ec3m\" (properties), which suited best in the context. Whereas, the baseline model without back translation translated to \"t\u00ednh c\u00e1ch\" (traits), typically one belonging to a person.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Observations",
                "sec_num": "5.3"
            },
            {
                "text": "In addition, in some cases, back translation also helps the model generate some additional words, which can help to increase the fluency of the translation sentences (Table 6 ). This enhances the nat- Baseline model: t\u00ednh c\u00e1ch c\u1ee7a b\u1ec7nh th\u01b0\u01a1ng h\u00e0n l\u00e0 b\u1ec7nh s\u1ed1t li\u00ean ti\u1ebfp, s\u1ed1t cao l\u00ean \u0111\u1ebfn 40 \u0111\u1ed9 c, \u0111\u1ed5 m\u1ed3 h\u00f4i qu\u00e1 nhi\u1ec1u, vi\u00eam d\u1ea1 d\u00e0y ru\u1ed9t v\u00e0 ti\u00eau ch\u1ea3y kh\u00f4ng c\u00f3 m\u00e0u.",
                "cite_spans": [],
                "ref_spans": [
                    {
                        "start": 166,
                        "end": 174,
                        "text": "(Table 6",
                        "ref_id": null
                    }
                ],
                "eq_spans": [],
                "section": "Observations",
                "sec_num": "5.3"
            },
            {
                "text": "Baseline model + Back translation: \u0111\u1eb7c \u0111i\u1ec3m c\u1ee7a b\u1ec7nh th\u01b0\u01a1ng h\u00e0n l\u00e0 s\u1ed1t li\u00ean ti\u1ebfp, s\u1ed1t cao l\u00ean t\u1edbi 40 \u0111\u1ed9 c, \u0111\u1ed5 m\u1ed3 h\u00f4i qu\u00e1 nhi\u1ec1u, vi\u00eam d\u1ea1 d\u00e0y v\u00e0 ti\u00eau ch\u1ea3y kh\u00f4ng c\u00f3 m\u00e0u. uralness of the generated expression for the target language.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Observations",
                "sec_num": "5.3"
            },
            {
                "text": "Participating in the machine translation shared task on VLSP 2020, we proposed some data cleaning and pre-processing for both monolingual and bilingual datasets. We did eliminate some very long or very short sentences as well as invalid characters (e.g. HTML, special ones). Some non-Vietnamese sentences in the monolingual dataset were also automatically removed. We proposed to use the transformer as the main translation model with backtranslation as a data augmentation technique. An intermediate translation system was built using the bilingual dataset as a training corpus. The backtranslation data were generated from the monolingual dataset by using the intermediate translation system. This back-translation data were then combined with the bilingual dataset to form the final training dataset for the final translation system.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Conclusion",
                "sec_num": "6"
            },
            {
                "text": "The experiment results on the IWSLT'15 English-Vietnamese test set suggested that the back-translation is an effective data augmentation technique for deep learning machine translation models, which made an enhancement from 36.3 to 38.7 of the BLEU score. With the test set of Machine Translation shared task of VLSP 2020, this technique seemed can adapt quite well on the news domain. Our system with the back-translation technique was ranked as the first place with the highest score of human evaluation (i.e. 1.55 points, compared to 1.33 of the second place). With the automatic evaluation, the system achieved a 32.1 Table 6 : More natural expression with back translation Input: thuan suggest to the delegation, in the short term to hurry up to prevent the epidemy, treat the disease, moreover, in the long term to make the whole team understand about malaria prevention method and therefore they will prevent disease for themselves which is also prevent disease for the whole team.",
                "cite_spans": [],
                "ref_spans": [
                    {
                        "start": 622,
                        "end": 629,
                        "text": "Table 6",
                        "ref_id": null
                    }
                ],
                "eq_spans": [],
                "section": "Conclusion",
                "sec_num": "6"
            },
            {
                "text": "Baseline model: thu\u1eadn g\u1ee3i \u00fd v\u1edbi ph\u00e1i \u0111o\u00e0n, trong th\u1eddi gian ng\u1eafn \u0111\u1ec3 nhanh ch\u00f3ng ng\u0103n ch\u1eb7n s\u1ef1 ph\u00e1t b\u1ec7nh, \u0111i\u1ec1u tr\u1ecb b\u1ec7nh, h\u01a1n n\u1eefa, trong l\u00e2u d\u00e0i \u0111\u1ec3 l\u00e0m cho to\u00e0n b\u1ed9 \u0111\u1ed9i hi\u1ec3u v\u1ec1 ph\u01b0\u01a1ng ph\u00e1p ph\u00f2ng ng\u1eeba b\u1ec7nh s\u1ed1t r\u00e9t v\u00e0 do \u0111\u00f3 h\u1ecd s\u1ebd ng\u0103n ch\u1eb7n b\u1ec7nh n\u00e0y cho ch\u00ednh h\u1ecd c\u0169ng s\u1ebd ng\u0103n ch\u1eb7n b\u1ec7nh n\u00e0y cho c\u1ea3 \u0111\u1ed9i.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Conclusion",
                "sec_num": "6"
            },
            {
                "text": "Baseline model +Back translation: \u00f4ng thu\u1eadn g\u1ee3i \u00fd cho ph\u00e1i \u0111o\u00e0n, trong th\u1eddi gian ng\u1eafn \u0111\u1ec3 nhanh ch\u00f3ng ng\u0103n ch\u1eb7n bi\u1ec3u m\u00f4, \u0111i\u1ec1u tr\u1ecb b\u1ec7nh, h\u01a1n n\u1eefa, v\u1ec1 l\u00e2u d\u00e0i \u0111\u1ec3 c\u1ea3 nh\u00f3m hi\u1ec3u v\u1ec1 ph\u01b0\u01a1ng ph\u00e1p ph\u00f2ng ng\u1eeba b\u1ec7nh s\u1ed1t r\u00e9t v\u00e0 do \u0111\u00f3 h\u1ecd s\u1ebd ng\u0103n ng\u1eeba b\u1ec7nh t\u1eadt cho b\u1ea3n th\u00e2n, \u0111i\u1ec1u n\u00e0y c\u0169ng s\u1ebd ng\u0103n ng\u1eeba b\u1ec7nh cho to\u00e0n \u0111\u1ed9i. BLEU score and a 0.50 TER score on VLSP 2020 Machine translation task test data.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Conclusion",
                "sec_num": "6"
            },
            {
                "text": "We will do some experiments on a number of sampling data methods during the preparation of back-translation datasets. We also consider analyzing and investigating the correspondences between human evaluation and automatic ones.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Conclusion",
                "sec_num": "6"
            },
            {
                "text": "Moses Open Source Toolkit for Machine Translation 2 https://github.com/rsennrich/subword-nmt",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "",
                "sec_num": null
            },
            {
                "text": "https://github.com/pytorch/fairseq",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "",
                "sec_num": null
            }
        ],
        "back_matter": [
            {
                "text": "This work was supported by the Vingroup Innovation Foundation (VINIF) under the project code DA116_14062019 / year 2019.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Ackknowledgement",
                "sec_num": null
            }
        ],
        "bib_entries": {
            "BIBREF0": {
                "ref_id": "b0",
                "title": "Neural Machine Translation by Jointly Learning to Align and Translate",
                "authors": [
                    {
                        "first": "Dzmitry",
                        "middle": [],
                        "last": "Bahdanau",
                        "suffix": ""
                    },
                    {
                        "first": "Kyunghyun",
                        "middle": [],
                        "last": "Cho",
                        "suffix": ""
                    },
                    {
                        "first": "Yoshua",
                        "middle": [],
                        "last": "Bengio",
                        "suffix": ""
                    }
                ],
                "year": 2016,
                "venue": "",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {
                    "arXiv": [
                        "arXiv:1409.0473"
                    ]
                },
                "num": null,
                "urls": [],
                "raw_text": "Dzmitry Bahdanau, Kyunghyun Cho, and Yoshua Ben- gio. 2016. Neural Machine Translation by Jointly Learning to Align and Translate. arXiv:1409.0473 [cs, stat]. ArXiv: 1409.0473.",
                "links": null
            },
            "BIBREF1": {
                "ref_id": "b1",
                "title": "Improving Translation Model by Monolingual Data",
                "authors": [],
                "year": null,
                "venue": "",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Ondr ej Bojar and Ales Tamchyna. Improving Translation Model by Monolingual Data. page 7.",
                "links": null
            },
            "BIBREF2": {
                "ref_id": "b2",
                "title": "Copied Monolingual Data Improves Low-Resource Neural Machine Translation",
                "authors": [
                    {
                        "first": "Anna",
                        "middle": [],
                        "last": "Currey",
                        "suffix": ""
                    },
                    {
                        "first": "Antonio",
                        "middle": [],
                        "last": "Valerio Miceli",
                        "suffix": ""
                    },
                    {
                        "first": "Kenneth",
                        "middle": [],
                        "last": "Barone",
                        "suffix": ""
                    },
                    {
                        "first": "",
                        "middle": [],
                        "last": "Heafield",
                        "suffix": ""
                    }
                ],
                "year": 2017,
                "venue": "Proceedings of the Second Conference on",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {
                    "DOI": [
                        "10.18653/v1/W17-4715"
                    ]
                },
                "num": null,
                "urls": [],
                "raw_text": "Anna Currey, Antonio Valerio Miceli Barone, and Ken- neth Heafield. 2017. Copied Monolingual Data Improves Low-Resource Neural Machine Transla- tion. In Proceedings of the Second Conference on",
                "links": null
            },
            "BIBREF3": {
                "ref_id": "b3",
                "title": "Association for Computational Linguistics",
                "authors": [],
                "year": null,
                "venue": "Machine Translation",
                "volume": "",
                "issue": "",
                "pages": "148--156",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Machine Translation, pages 148-156, Copenhagen, Denmark. Association for Computational Linguis- tics.",
                "links": null
            },
            "BIBREF4": {
                "ref_id": "b4",
                "title": "Understanding Back-Translation at Scale",
                "authors": [
                    {
                        "first": "Sergey",
                        "middle": [],
                        "last": "Edunov",
                        "suffix": ""
                    },
                    {
                        "first": "Myle",
                        "middle": [],
                        "last": "Ott",
                        "suffix": ""
                    },
                    {
                        "first": "Michael",
                        "middle": [],
                        "last": "Auli",
                        "suffix": ""
                    },
                    {
                        "first": "David",
                        "middle": [],
                        "last": "Grangier",
                        "suffix": ""
                    }
                ],
                "year": 2018,
                "venue": "",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {
                    "arXiv": [
                        "arXiv:1808.09381[cs].ArXiv:1808.09381"
                    ]
                },
                "num": null,
                "urls": [],
                "raw_text": "Sergey Edunov, Myle Ott, Michael Auli, and David Grangier. 2018. Understanding Back-Translation at Scale. arXiv:1808.09381 [cs]. ArXiv: 1808.09381.",
                "links": null
            },
            "BIBREF5": {
                "ref_id": "b5",
                "title": "Convolutional Sequence to Sequence Learning",
                "authors": [
                    {
                        "first": "Jonas",
                        "middle": [],
                        "last": "Gehring",
                        "suffix": ""
                    },
                    {
                        "first": "Michael",
                        "middle": [],
                        "last": "Auli",
                        "suffix": ""
                    },
                    {
                        "first": "David",
                        "middle": [],
                        "last": "Grangier",
                        "suffix": ""
                    },
                    {
                        "first": "Denis",
                        "middle": [],
                        "last": "Yarats",
                        "suffix": ""
                    },
                    {
                        "first": "Yann",
                        "middle": [
                            "N"
                        ],
                        "last": "Dauphin",
                        "suffix": ""
                    }
                ],
                "year": 2017,
                "venue": "",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {
                    "arXiv": [
                        "arXiv:1705.03122[cs].ArXiv:1705.03122"
                    ]
                },
                "num": null,
                "urls": [],
                "raw_text": "Jonas Gehring, Michael Auli, David Grangier, Denis Yarats, and Yann N. Dauphin. 2017. Convolutional Sequence to Sequence Learning. arXiv:1705.03122 [cs]. ArXiv: 1705.03122.",
                "links": null
            },
            "BIBREF6": {
                "ref_id": "b6",
                "title": "Convolutional Neural Network for Modelling Sentences",
                "authors": [
                    {
                        "first": "Nal",
                        "middle": [],
                        "last": "Kalchbrenner",
                        "suffix": ""
                    },
                    {
                        "first": "Edward",
                        "middle": [],
                        "last": "Grefenstette",
                        "suffix": ""
                    },
                    {
                        "first": "Phil",
                        "middle": [],
                        "last": "Blunsom",
                        "suffix": ""
                    }
                ],
                "year": 2014,
                "venue": "",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {
                    "arXiv": [
                        "arXiv:1404.2188"
                    ]
                },
                "num": null,
                "urls": [],
                "raw_text": "Nal Kalchbrenner, Edward Grefenstette, and Phil Blun- som. 2014. A Convolutional Neural Network for Modelling Sentences. arXiv:1404.2188 [cs].",
                "links": null
            },
            "BIBREF7": {
                "ref_id": "b7",
                "title": "Effective Approaches to Attention-based Neural Machine Translation",
                "authors": [
                    {
                        "first": "Minh-Thang",
                        "middle": [],
                        "last": "Luong",
                        "suffix": ""
                    },
                    {
                        "first": "Hieu",
                        "middle": [],
                        "last": "Pham",
                        "suffix": ""
                    },
                    {
                        "first": "Christopher",
                        "middle": [
                            "D"
                        ],
                        "last": "Manning",
                        "suffix": ""
                    }
                ],
                "year": 2015,
                "venue": "",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {
                    "arXiv": [
                        "arXiv:1508.04025[cs].ArXiv:1508.04025"
                    ]
                },
                "num": null,
                "urls": [],
                "raw_text": "Minh-Thang Luong, Hieu Pham, and Christo- pher D. Manning. 2015. Effective Approaches to Attention-based Neural Machine Translation. arXiv:1508.04025 [cs]. ArXiv: 1508.04025.",
                "links": null
            },
            "BIBREF8": {
                "ref_id": "b8",
                "title": "Improving Neural Machine Translation Models with Monolingual Data",
                "authors": [
                    {
                        "first": "Rico",
                        "middle": [],
                        "last": "Sennrich",
                        "suffix": ""
                    },
                    {
                        "first": "Barry",
                        "middle": [],
                        "last": "Haddow",
                        "suffix": ""
                    },
                    {
                        "first": "Alexandra",
                        "middle": [],
                        "last": "Birch",
                        "suffix": ""
                    }
                ],
                "year": 2016,
                "venue": "",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {
                    "arXiv": [
                        "arXiv:1511.06709"
                    ]
                },
                "num": null,
                "urls": [],
                "raw_text": "Rico Sennrich, Barry Haddow, and Alexandra Birch. 2016. Improving Neural Machine Translation Mod- els with Monolingual Data. arXiv:1511.06709 [cs].",
                "links": null
            },
            "BIBREF9": {
                "ref_id": "b9",
                "title": "Sequence to Sequence Learning with Neural Networks",
                "authors": [
                    {
                        "first": "Ilya",
                        "middle": [],
                        "last": "Sutskever",
                        "suffix": ""
                    },
                    {
                        "first": "Oriol",
                        "middle": [],
                        "last": "Vinyals",
                        "suffix": ""
                    },
                    {
                        "first": "V",
                        "middle": [],
                        "last": "Quoc",
                        "suffix": ""
                    },
                    {
                        "first": "",
                        "middle": [],
                        "last": "Le",
                        "suffix": ""
                    }
                ],
                "year": 2014,
                "venue": "",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {
                    "arXiv": [
                        "arXiv:1409.3215[cs].ArXiv:1409.3215"
                    ]
                },
                "num": null,
                "urls": [],
                "raw_text": "Ilya Sutskever, Oriol Vinyals, and Quoc V. Le. 2014. Sequence to Sequence Learning with Neural Net- works. arXiv:1409.3215 [cs]. ArXiv: 1409.3215.",
                "links": null
            },
            "BIBREF10": {
                "ref_id": "b10",
                "title": "Goals, challenges and findings of the vlsp 2020 english-vietnamese news translation shared task",
                "authors": [
                    {
                        "first": "Ha",
                        "middle": [],
                        "last": "Thanh-Le",
                        "suffix": ""
                    },
                    {
                        "first": "Tran",
                        "middle": [],
                        "last": "Van-Khanh",
                        "suffix": ""
                    },
                    {
                        "first": "Nguyen",
                        "middle": [],
                        "last": "Kim-Anh",
                        "suffix": ""
                    }
                ],
                "year": 2020,
                "venue": "Proceedings of the Seventh International Workshop on Vietnamese Language and Speech Processing",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Ha Thanh-Le, Tran Van-Khanh, and Nguyen Kim-Anh. 2020. Goals, challenges and findings of the vlsp 2020 english-vietnamese news translation shared task. Proceedings of the Seventh International Workshop on Vietnamese Language and Speech Pro- cessing (VLSP 2020).",
                "links": null
            },
            "BIBREF11": {
                "ref_id": "b11",
                "title": "Learning Machine Translation",
                "authors": [
                    {
                        "first": "V",
                        "middle": [],
                        "last": "Vandeghinste ; * Cyril Goutte",
                        "suffix": ""
                    },
                    {
                        "first": "Nicola",
                        "middle": [],
                        "last": "Cancedda",
                        "suffix": ""
                    },
                    {
                        "first": "Marc",
                        "middle": [],
                        "last": "Dymetman",
                        "suffix": ""
                    },
                    {
                        "first": "George",
                        "middle": [],
                        "last": "Foster",
                        "suffix": ""
                    }
                ],
                "year": 2011,
                "venue": "Literary and Linguistic Computing",
                "volume": "26",
                "issue": "4",
                "pages": "484--486",
                "other_ids": {
                    "DOI": [
                        "10.1093/llc/fqr030"
                    ]
                },
                "num": null,
                "urls": [],
                "raw_text": "V. Vandeghinste. 2011. Learning Machine Translation. * Cyril Goutte, Nicola Cancedda, Marc Dymetman, and George Foster. Literary and Linguistic Comput- ing, 26(4):484-486.",
                "links": null
            },
            "BIBREF13": {
                "ref_id": "b13",
                "title": "Improving Neural Language Modeling via Adversarial Training",
                "authors": [
                    {
                        "first": "Dilin",
                        "middle": [],
                        "last": "Wang",
                        "suffix": ""
                    },
                    {
                        "first": "Chengyue",
                        "middle": [],
                        "last": "Gong",
                        "suffix": ""
                    },
                    {
                        "first": "Qiang",
                        "middle": [],
                        "last": "Liu",
                        "suffix": ""
                    }
                ],
                "year": 2019,
                "venue": "",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {
                    "arXiv": [
                        "arXiv:1906.03805"
                    ]
                },
                "num": null,
                "urls": [],
                "raw_text": "Dilin Wang, Chengyue Gong, and Qiang Liu. 2019. Improving Neural Language Modeling via Adversar- ial Training. arXiv:1906.03805 [cs, stat]. ArXiv: 1906.03805.",
                "links": null
            }
        },
        "ref_entries": {
            "FIGREF0": {
                "uris": null,
                "type_str": "figure",
                "num": null,
                "text": "The proposed system architecture."
            },
            "FIGREF1": {
                "uris": null,
                "type_str": "figure",
                "num": null,
                "text": "Transformer architecture."
            },
            "FIGREF2": {
                "uris": null,
                "type_str": "figure",
                "num": null,
                "text": "Count clip (ngram) C \u2208Candidates ngram \u2208C Count clip (ngram )"
            },
            "TABREF0": {
                "text": "The bilingual dataset on multi-domains",
                "html": null,
                "content": "<table><tr><td>Dataset</td><td>Domain</td><td>Size</td></tr><tr><td/><td/><td>(sentences)</td></tr><tr><td>News</td><td>News (in-domain)</td><td>20.0K</td></tr><tr><td>Basic</td><td>Basic conversations</td><td>8.8K</td></tr><tr><td>EVBCorpus</td><td>Mixed domains</td><td>45.0K</td></tr><tr><td>TED-like</td><td>EduTech talks</td><td>546.0K</td></tr><tr><td>Wiki-ALT</td><td>Wikipedia articles</td><td>20.0K</td></tr><tr><td colspan=\"2\">OpenSubtitle Movie Subtitles</td><td>3.5M</td></tr></table>",
                "type_str": "table",
                "num": null
            },
            "TABREF1": {
                "text": "Experimental results for the back translation on the IWSLT'15 English-Vietnamese test set",
                "html": null,
                "content": "<table><tr><td>Model</td><td>BLEU score</td></tr><tr><td>Transformer (baseline)</td><td>36.3</td></tr><tr><td>Transformer + Back-Translation</td><td>38.7</td></tr><tr><td colspan=\"2\">5.2 VLSP 2020 Experimental Results</td></tr><tr><td colspan=\"2\">VLSP organizers released 2 test sets: a public test</td></tr><tr><td colspan=\"2\">set and a private test set. The public test has 1220</td></tr><tr><td colspan=\"2\">pairs in the news domain while the private test is</td></tr><tr><td colspan=\"2\">collected from online newspapers about Covid-19</td></tr><tr><td>news articles, about 789 pairs.</td><td/></tr><tr><td colspan=\"2\">The result running on the private test is shown</td></tr><tr><td>in</td><td/></tr></table>",
                "type_str": "table",
                "num": null
            },
            "TABREF2": {
                "text": "Score of systems by VLSP organizer",
                "html": null,
                "content": "<table><tr><td>Team</td><td colspan=\"2\">BLEU TER Human score</td></tr><tr><td>Our System*</td><td>32.10 0.50</td><td>1.554</td></tr><tr><td>EngineMT</td><td>38.39 0.45</td><td>1.327</td></tr><tr><td>RD-VAIS</td><td>33.89 0.53</td><td>0.864</td></tr></table>",
                "type_str": "table",
                "num": null
            },
            "TABREF3": {
                "text": "Removing duplicated pronounces with back translation",
                "html": null,
                "content": "<table/>",
                "type_str": "table",
                "num": null
            },
            "TABREF4": {
                "text": "More suitable terms with back translation Input: typhoid's characteristics are continuous fever , high fever up to 40 \u2022 C , excessive sweating , gastroenteritis and uncolored diarrhea.",
                "html": null,
                "content": "<table/>",
                "type_str": "table",
                "num": null
            }
        }
    }
}