Yuya Sawada


2025

pdf bib
A Text Embedding Model with Contrastive Example Mining for Point-of-Interest Geocoding
Hibiki Nakatani | Hiroki Teranishi | Shohei Higashiyama | Yuya Sawada | Hiroki Ouchi | Taro Watanabe
Proceedings of the 31st International Conference on Computational Linguistics

Geocoding is a fundamental technique that links location mentions to their geographic positions, which is important for understanding texts in terms of where the described events occurred. Unlike most geocoding studies that targeted coarse-grained locations, we focus on geocoding at a fine-grained point-of-interest (POI) level. To address the challenge of finding appropriate geo-database entries from among many candidates with similar POI names, we develop a text embedding-based geocoding model and investigate (1) entry encoding representations and (2) hard negative mining approaches suitable for enhancing the model’s disambiguation ability. Our experiments show that the second factor significantly impact the geocoding accuracy of the model.

2020

pdf bib
Coordination Boundary Identification without Labeled Data for Compound Terms Disambiguation
Yuya Sawada | Takashi Wada | Takayoshi Shibahara | Hiroki Teranishi | Shuhei Kondo | Hiroyuki Shindo | Taro Watanabe | Yuji Matsumoto
Proceedings of the 28th International Conference on Computational Linguistics

We propose a simple method for nominal coordination boundary identification. As the main strength of our method, it can identify the coordination boundaries without training on labeled data, and can be applied even if coordination structure annotations are not available. Our system employs pre-trained word embeddings to measure the similarities of words and detects the span of coordination, assuming that conjuncts share syntactic and semantic similarities. We demonstrate that our method yields good results in identifying coordinated noun phrases in the GENIA corpus and is comparable to a recent supervised method for the case when the coordinator conjoins simple noun phrases.