12th Dec 2016, WAT 2016

M. Fuji, M. Utiyama, E. Sumita, Y. Matsumoto

Summary• Improve translation of formal documents
between distant languages by global reordering• Learn global reordering model from nonannotated bilingual corpora• Substantial improvement with global
reordering + conventional reordering for JE
translation

Proposed: Global Pre-ordering
1. Detect segments using characteristic strings
2. Globally reorder detected segments
3. Apply conventional reordering to each segment

Experiment

Analysis

Experiment settings

Results Ja->En• Data:Prepare training data• Extract sentences containing global reordering Regard sentence to contain global reordering if segments inswap orientation in alignment table
する
提供を装置
画像できる
発信を信号

Segment
boundary A

Background

Segment
boundary B

Toprovideanimagedevicecapableofsendingsignals– Eg. Operation manuals, law docs, patent docs

• Difficult to translate because:– Sentences are long
– Requires “global reordering” between distantlanguages– Out of SMT training sentences, 100,000 pairs used.
– Out of 100,000 pairs, 38,194 pairs required globalreordering.
– 38,194 pairs used to train SVM global reordering model

Input to SVM• 10-fold cross validation: Ja-En

To provide a communication apparatus capable of performing
highly reliable communication.

If segment
boundary

To provide an image formation device which enables high image
quality images to be formed.

<BOS> To

provide an×

To provide

an image✓

provide animage device×

an imagedevice capable×

image device

capable of✓device capableof sending

×T4: To provide a toner cake layer forming device for generating toner cake layer
having a high solid content, and operable by an electrostatic printing engine.
13• Human eval added(if boundary)

Globalpreord

DecodeDetectsegments

Globalreordering

Conventional

reordering

Segments in correct order + Each segment improved

Results En->Ja

Train segment
detection

SVM model

Input
sentence

T4

Results Ja->En

高画質な画像を形成できる画像形成装置を提供する。

– Segment boundaries marked with characteristic strings– Global reordering occurring at segment level

RIBES close to human + Proposed method effective

T3: For generating toner cake layer having a high solids content and to provide a
toner cake layer forming device which can be operated by an electrostatic printing
engine.

SVM

信頼性の高い通信を行うことができる通信装置を提供すること。

1533362765

Reference: To provide a toner cake layer forming apparatus which forms a tonercake layer having a high solid content and which can be actuated by anelectrostatic printing engine.

Reference

RHS 2-grams

Reference

123121
2758

44.9
61.0
64.9
64.6
72.1

T2: To provide toner cake layer forming apparatus of the solid content of hightoner cake layer for generating an electrostatic print engine can be operated.

Experiment configuration
Input(n-grams)

17.9
19.3
25.5
22.3
25.6

T1: Solid content of high toner cake layer for generating an electrostatic print
engine operates in a toner cake layer forming device.

LHS 2-grams
RHSn-gramㇾStruct Humanureeval

Example translation– Input: n-grams at each position– Reference: whether position is a segment boundary• Example: Patent abstract• Features

ㇾTDBTGBLEU RIBES

φ3

Use n-grams to represent characteristic strings

LHSn-gramPreordtype

Syntacticㇾ

T411Convent.
preordㇾT3

φ1Train segment boundaries

Translation between distant languages

Sentencepair 2

T1
T2

SVM tuning

Positionin question

Sentencepair 1

Globalpreord• Global reordering module:

Background• Large volumes of formal documents aretranslated in industry• Human eval added– Patent Abstract of Japan (PAJ) with its original Japanese
patents automatically aligned.
– 1,000,000 sentence pairs for SMT training. 1,000 for
developing and testing.

φ2

NICT, NAIST

SMT

Outputsentence

T1
T2
T3
T4

Syntactic
preord

ㇾ
ㇾㇾㇾ

BLEU
17.9
19.3
25.5
25.6

RIBESGlobal
preord

T1
T2
T3

44.9
61.0
64.9
72.1

Convent.
preordPreordtypeㇾ
ㇾSyntactic

TDBTG
T4

Improvement in RIBES but not in BLEU

ㇾㇾBLEU RIBESStruct Human
ureeval

32.1
29.1
36.9
34.9
36.5

28
26
67
59
68

59.1
65.3
76.1
77.7
77.7

12955
3755

Proposed method NOT so effective for En->Ja14