JChampollion is a Java implementation of the Champollion program described by Smadja, McKeown and Hatzivassiloglou in this paper:
JChampollion accepts a sentence-aligned, bilingual corpus and a collocation in the source text (such as those produced by Xtract) and produces a translation of the collocation in the target language. What's a collocation? A collocation is defined as "recurrent combinations of words that co-occur more often than expected by chance and that correspond to arbitrary word usages." Basically, they're groups of words that often go together and usually mean something different when together than when they're apart. Examples are "The United Nations" and "Natural Language Processing".
The original Champollion was written for English as the source text and French as the target text, and used the Hansards Corpus for evaluation. JChampollion uses English as the source language and German as the target language. Development and testing was done with the Europarl Corpus.
Here are some example translations produced by JChampollion:
| Source Language Collocation | JChampollion Output |
|---|---|
| Madam President | frau präsidentin |
| member states | mitgliedstaaten |
| the committee on agriculture and rural development | landwirtschaft ländliche |
| report on competition policy | wettbewerbspolitik |
JChampollion was implemented as part of a grad school semester project. More information about that project is available at the project page.
JChampollion is as close to the original implementation of Champollion as could be achieved from reading the paper describing its algorithm. The only detail that is left vague concerns closed class words. The authors of the paper mention that they do not return closed class words from the target language in their translations, because their frequency messes up the statistical correlation data for the rest of the corpus. However, they don't specify exactly which closed class words they exclude. In JChampollion, most of the German articles and prepositions are excluded (with some morphological differences accounted for), but nothing else. Nevertheless, the lack of prepositions and articles greatly reduces the accuracy of the translations.
The index files for the corpus are rather large, about 50% larger than the corpus itself. Ideally the index would be kept in memory, but as the corpus size grows, this becomes impractical. So, the index is loaded from disk.
Note: this software was written as a student project over a few days in 2005 for the Natural Language Processing course EECS 595 at the University of Michigan. It might be useful or interesting, but it almost certainly has bugs.
First, make sure you have Java installed. Then, after cloning the repository, you'll need to build the software. JChampollion uses Gradle Wrapper, so you can build everything with this command:
$ ./gradlew installDist
You'll need a sentence-aligned English-German corpus. Development was done with files from the Europarl Corpus.
Once you've built the software and you have corpus files, you can run JChampollion. Running it without any arguments will print some help information:
$ ./build/install/JChampollion/bin/JChampollion
The first time you run JChampollion on a given corpus, you must include the
-index argument, so the corpus will be indexed. You must also tell
JChampollion where to find the source and target files, as well as which
collocation should be translated.
./build/install/JChampollion/bin/JChampollion -source ./ep-00-en.txt -target ./ep-00-de.txt -co "member state" -index
On subsequent runs you don't need to include the -index argument, as long
as the corpus doesn't change.
./build/install/JChampollion/bin/JChampollion -source ./ep-00-en.txt -target ./ep-00-de.txt -co "member state"
This code is free software licensed under the GPL v3. See the COPYING file for details.