Hayato Ohwada

AAAI Conference 2026 Short Paper

Domain-Specific Retrieval for Retrieval-Augmented Generation: A Case Study on Pertussis Research (Student Abstract)

• Hiroki Takabatake
• Niken Prasasti Martono
• Asaomi Kuwae
• Toshihiko Iuchi
• Hayato Ohwada

Integrating knowledge from scientific literature is essential in biomedical research. However, the rapid growth of scientific literature makes staying up to date increasingly challenging. Retrieval-Augmented Generation (RAG) offers a promising framework, but its effectiveness in specialized biomedical domains remains unclear. In this work, we propose a two-stage retrieval pipeline for RAG, with a focus on Bordetella pertussis as a case study. Our method first applies hard filtering with synonym expansion to eliminate irrelevant passages, and then performs hybrid search, followed by reranking. We evaluate our approach using a dataset of 58 pertussis-related queries with automatic relevance judgments from multiple large language models (LLMs). Experimental results show that our pipeline improves MAP@10 by 13.4-20.4 points compared with existing methods and achieves the highest MRR@10. Furthermore, consistent improvements across different LLMs highlight the effectiveness of our approach.

AAAI Conference 2016 Conference Paper

Inductive Logic Programming: Challenges

• Katsumi Inoue
• Hayato Ohwada
• Akihiro Yamamoto

TCS Journal 2003 Journal Article

Integrating information visualization and retrieval for WWW information discovery

• Hayato Ohwada
• Fumio Mizoguchi

An important technology in knowledge discovery is to access the desired information from the large amount of data stored on the WWW. At present, such information can be accessed by a browser itself or by using a keyword search function. However, browsing is a time consuming task where a user must access individual pages one by one. Furthermore, in keyword searches, it is difficult for users to provide reasonable keywords in knowledge discovery processes. This paper outlines an approach for integrating information visualization and retrieval into WWW information discovery. In this approach, the link structure of a web site is displayed in a 3-D hyperbolic tree in which the height of a node (corresponding to a web page) within the tree indicates a user's “interest” for each page. Here, interest is calculated by a fitting function between a page and a user-supplied query (nested keywords). This measure can be used to filter uninteresting pages, reducing the size of the link structure. Furthermore, each web page is modeled as semi-structured data and can also be displayed as a hyperbolic tree in which the result of query evaluation is visible. Such functions are incorporated within our browser, allowing us to interactively discover desired pages from a large web site. We selected typical web sites to show the performance of the proposed method with improved accuracy and efficiency in WWW information discovery. Here, accuracy indicates how surely the user accesses his/her desired documents, and efficiency indicates how quickly the user reaches the documents.

IROS Conference 1998 Conference Paper

Logic specifications for multiple robots based on a current programming language

• Hiroyuki Nishiyama
• Hayato Ohwada
• Fumio Mizoguchi

The paper describes a concurrent logic specification language for developing programs that control multiple robots. This language is based on guarded Horn clauses and specifications are atomically transformed into concurrent logic programs, yielding executable specifications. They makes it possible to easily implement complex tasks such as concurrency control, communication and multiagent-type profile, solving for multiple robots. An experiment on program development for multiple manipulators was undertaken to show advantages of the specification language. The resulting observations are twofold. First, specifications are more abstract and natural than conventional procedure-oriented programs. Second the amounts of specifications are very shorter than that of the programs developed by the underlying concurrent logic programs are then compiled into C programs with little overhead the proposed language can be useful as a multiple robot programming language with the efficiency for both program execution and developed.

IROS Conference 1998 Conference Paper

Web-based communication and control for multiagent robots

• Hironori Hiraishi
• Hayato Ohwada
• Fumio Mizoguchi

In this paper we describe a Web-based method for communication with and control of heterogeneous robots in a unified manner, including mobile robots and vision sensors. We base this method on recent Web technologies such as browsers, Java language and socket communication. It allows users to connect to robots through a Web server, using their hand-held computers, and to monitor and control the robots via various input devices. As a model of an everyday working environment, we configured mobile robots and cameras that work autonomously and cooperatively. The Web technologies provide a general framework for integrating robot control, communication between robots and humans, and Web-page access. This framework can extend the robot-based intelligent office as a new direction of the intranet.