Yasuyoshi Inagaki

Stochastic dependency parsing of spontaneous Japanese spoken language

This paper describes the characteristic features of dependency structures of Japanese spoken language by investigating a spoken dialogue corpus, and proposes a stochastic approach to dependency parsing. The method can robustly cope with inversion phenomena and bunsetsus which dont have the head bunsetsu by relaxing the syntactic dependency constraints. The method acquires in advance the probabilities of dependencies from a spoken dialogue corpus tagged with dependency structures, and provides the most plausible dependency structure for each utterance on the basis of the probabilities. An experiment on dependency parsing for drivers utterances in CIAIR in-car spoken dialogue corpus has been made. The experimental result has shown our method to be effective for robust parsing of spoken language.

Incremental parsing for interactive natural language interface

The paper proposes an effective incremental parsing method for such interactive natural language processing systems as real-time dialogue systems, simultaneous machine interpreting systems, etc. This method produces the analysis of the input while it is being received. It can efficiently deal with not only the normal input, which is piecemeal addition to the input from left to right, but also such changes of the input as insertion and deletion. For such changes of the input, this method exploits parts of the previous analyses. We implemented this method on a workstation and conducted an experiment. We confirm that the method can be expected to be useful for an online language processing system.

Sync/Trans: Simultaneous Machine Interpretation between English and Japanese

This paper describes Sync/Trans, an incremental spoken language translation system. The system has been being developed for efficiently translating a spontaneous speech dialogue between an English speaker and a Japanese speaker. Its purpose being to behave as a simultaneous interpreter, the system produces the target output synchronously with the source input. Sync/Trans has the following features: (1) the system consists of modules that work in a synchronous fashion, (2) the system translates the source language possibly word-by-word according to the appearance order, (3) the system utilizes grammatically ill-formed expressions for the speech output, and (4) the system corrects the grammatical ill-formedness of the speech input at a pretty early stage. An experimental system for translating EngUsh speech into Japanese speech has been implemented. A few experimental results have shown Sync/Treins to be a promising system for simultaneous interpretation.

Ad hoc network system based on infrared communication

Recently, it becomes popular to use small size computers such as notebook computers or PDAs in the mobile environment. It sometimes happens that several computers meet at the same place such as meeting rooms or conference sites. In such environment, there are demands to make a direct communication among mobile computers. Route maintenance and host enumeration are key requirement for such an ad hoc network. In this paper, we propose a network system based on infrared communication. Our system solves host enumeration as well as route maintenance using diffusing computation. We describe autonomous communication protocol for the ad hoc network and an implementation of mobile system using the protocol.

An Experiment on Japanese-Uighur Machine Translation and Its Evaluation

This paper describes an evaluation experiment about a Japanese-Uighur machine translation system which consists of verbal suffix processing, case suffix processing, phonetic change processing, and a Japanese-Uighur dictionary including about 20,000 words. Japanese and Uighur have many syntactical and language structural similarities, including word order, existence and same functions of case suffixes and verbal suffixes, morphological structure, etc. For these reasons, we can consider that we can translate Japanese into Uighur in such a manner as word-by-word aligning after morphological analysis of the input sentences without complicated syntactical analysis. From the point of view of practical usage, we have chosen three articles about environmental issue appeared in Nippon Keizai Shinbun, and conducted a translation experiment on the articles with our MT system, for clarifying our argument. Here, we have counted the correctness of phrases in the Output sentences to be evaluating criteria. As a results of the experiment, 84.8% of precision has been achieved.

Derivational Grammar Approach to Morphological Analysis of Japanese Sentences

This paper proposes a new simple Japanese morphological analysis system which we call MAJO. Of course, many Japanese morphological analyses have been proposed and used in the wide area of Japanese language processing. But they are rather complicated because their analysis methods are based on conjugations of verbs and adjectives. On the other hand, it is known that the derivational grammar, which does not use the concept of conjugations, makes morphological analysis simple. Although there are some literatures which discuss Japanese morphological analysis used derivational grammar, all of them has modified their grammar to utilize existing systems. MAJO is constructed directly from the derivational grammar, so that it has a smaller number of grammar rules than the previous systems. We have evaluated its performance on the EDR corpus and MAJO succeeded with 97.9% ratio.