Make the Japanese-English Word Dictionary

Translating only one way from Japanese to English will result in an unreliable dictionary. Thus, we used both Japanese-English word pairs and English-Japanese word pairs to make the dictionary.

The word dictionary was made as follows.

Step 1

Make Japanese-English word pairs and English-Japanese word pairs using GIZA++.

Step 2

Multiply the translation probabilities of the Japanese-English word pairs and English-Japanese word pairs. Select the word pairs with probabilities higher than a threshold ($\alpha$ ) and put them in the dictionary.

GIZA++[3] gets the source language and the target language word pairs by using the maximum likelihood correspondence from the source sentences and the target sentences. It also assigns a translation probability. In this experiment, we used GIZA++ to obtain Japanese-English word pairs and English-Japanese word pairs. Examples of using GIZA++ are shown in Tables 3 and 4.

Table 3: Example of Japanese-English Word Pairs found by GIZA++

図	Fig.	0.37
特性	characteristic	0.49

Table 4: Example of English-Japanese Word Pairs found by GIZA++

FIG	図	0.22
characteristic	特性	0.71

Table 5 shows an example of the Japanese-English word dictionary.

Table 5: Example entries of the Japanese-English Word Dictionary

図	Fig.	0.08
特性	characteristic	0.34