Hayato Ohwada

dblp:81/6984 · DBLP profile ↗
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41ranked-venue papers
5as first author
6since 2021 · last 2026
0000-0001-5621-6984ORCID · corroborated

Domains — the database's venue-derived domains; a paper can count in several

Artificial intelligence and machine learning · 34 · 4 first-author · 5 since 2021Human-computer interaction and ubiquitous computing · 9 · 3 since 2021Applied, interdisciplinary, general and emerging computing · 9 · 2 first-authorDatabases, data management, data science and information retrieval · 5 · 1 since 2021Theory of computation · 4 · 2 first-authorGraphics, computer vision, multimedia, augmented reality and games · 3 · 1 since 2021Systems, architecture and hardware · 2
YearPublicationVenuePosition
2026 Domain-Specific Retrieval for Retrieval-Augmented Generation: A Case Study on Pertussis Research (Student Abstract)
abstract
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.
Hiroki Takabatake, Niken Prasasti, Asaomi Kuwae, Toshihiko Iuchi, Hayato Ohwada
AAAI5
2025 Learning Programming for Non-Native English-Speaking Students: Insight from Japanese Students
abstract
For non-native English speakers, learning programming presents unique challenges, particularly in languages like Python, which heavily rely on English syntax and documentation. This study explores the challenges faced by non-native English-speaking Japanese university students enrolled in introductory Python programming courses. A survey was held to examined various aspects of their learning experience, including their programming proficiency, English fluency, use of translation tools, and the impact of bilingual resources on their learning. Clustering analysis was employed to group the participants into three distinct clusters: beginners, intermediate learners, and advanced learners. Cluster 0 (beginners) had low programming experience and English fluency, relying on non-English materials and translation tools. Cluster 1 (intermediate) showed moderate skills, using bilingual resources and translation aids. Cluster 2 (advanced) had higher proficiency but faced challenges with debugging and code optimization. Our findings highlight the need for tailored resources to support students navigating English-based programming environments.
Niken Prasasti, Hayato Ohwada
SIGCSE (2)2
2024 Precision 3D Motion Capture Using Pose Estimation Techniques: Application in Sports Video Analysis
Shuzo Kitano, Akimasa Ebihara, Tomohide Sawada, Niken Prasasti, Hayato Ohwada
PKAW5
2023 Automated Cattle Behavior Classification Using Wearable Sensors and Machine Learning Approach
Niken Prasasti, Rie Sawado, Itoko Nonaka, Fuminori Terada, Hayato Ohwada
PKAW5
2022 ECG Signal Classification Using Recurrence Plot-Based Approach and Deep Learning for Arrhythmia Prediction
Niken Prasasti, Toru Nishiguchi, Hayato Ohwada
ACIIDS (1)3
2021 Advances in Hybrid Evolutionary Algorithms for Fuzzy Flexible Job-shop Scheduling: State-of-the-Art Survey
Mitsuo Gen, Lin Lin 0008, Hayato Ohwada
ICAART (1)3
2019 Classification Model for Cerebral Aneurysm Rupture Prediction using Medical and Blood-flow-simulation Data
abstract
Stroke is a serious cerebrovascular condition, in which brain cells die due to an abrupt blockage of arteries supplying blood and oxygen or due to bleeding in the brain tissue when a blood vessel bursts or ruptures. Because stroke occurs suddenly in most people, prevention is oftentimes difficult. In Japan, this condition is one of the major causes of death, which is associated with high medical cost, especially among the society’s aging population. Therefore, stroke prediction and treatment is important. Stroke incidences can be avoided by a preventive treatment based on the risk of onset. However, since judgment of the onset risk largely depends on the individual experience and skill of the doctor, a highly accurate prediction method that is independent of the doctor’s experience and skill is the focus of this study. The target of prediction for this research is subarachnoid hemorrhage that is part of stroke. Logistic regression and support vector machine that predict cerebral aneurysm rupture by machine learning using combined medical data and cerebral blood-flow-simulation data were employed to analyze 338 cerebral aneurysm samples (35 ruptured, 303 unruptured). SMOTE algorithm solved the imbalance of data, while the SelectKBest algorithm was used to extract important features from the total 70 features obtained from both data. Out of the 27 important features extracted, 40% belonged to the medical data and the remaining 60% were from the blood-flow-simulation data. Using logistic regression as a classification model, we found the sensitivity of 0.64 and the specificity of 0.85. The results validated the possibility of a highly accurate method of cerebral aneurysm rupture prediction by machine learning using engineering information obtained from mechanical simulation.
Masaaki Suzuki, Toshiyuki Haruhara, Hiroyuki Takao, Soichiro Fujimura, Toshihiro Ishibashi, Makoto Yamamoto, Yuichi Murayama, Hayato Ohwada
ICAART (2)9
2018 Deep 3D Convolutional Neural Network Architectures for Alzheimer's Disease Diagnosis
Hiroki Karasawa, Chien-Liang Liu, Hayato Ohwada
ACIIDS (1)3
2018 New Survival Prediction System for Terminal Patients based on Machine Learning
Tatsuki Hirozawa, Takeshi Yamada, Hayato Ohwada
BIBM3
2018 Regression Models and Ranking Method for p53 Inhibitor Candidates Using Machine Learning
Haruka Motohashi, Tatsuro Teraoka, Shin Aoki, Hayato Ohwada
BIBM4
2018 Classification of CSR Using Latent Dirichlet Allocation and Analysis of the Relationship Between CSR and Corporate Value
Kazuya Uekado, Masaaki Suzuki, Hayato Ohwada
PKAW4
2017 Predicting radiation protection and toxicity of p53 targeting radioprotectors using machine learning
abstract
This paper explores machine learning application in the case of drug discovery. We apply extreme gradient boosting and K-nearest neighbor to biomedical data and it signiflcantly outperform former studies using feature selection and proper tuning parameters. The novel application motivated by a recent circumstance that there is a need for rapid development of radio-protectors. It mainly targets the DNA of growing cancer cells, whereas it has adverse side effects, including p53-induced apoptosis of normal tissues and cells. It considered that p53 would be a target for therapeutic and mitigated radioprotection to escape from the apoptotic fate. On the other hand, many types of compounds contain several level of toxicity, so it is important to consider not only radiation protection but also the level of toxicity of candidate compounds for radioprotectors. Compounds of radio-protectors that have low toxicity and high radiation protection are expected. It is possible to do efficiently the compounds discovery using machine learning. This study predicts compounds of radioprotectors using plural machine learning methods, Extreme Gradient Boosting, K-nearest neighbor, SVM and Random Forest. We compare these methods and suggest proper methods to predict radioprotectors.
Masataka Kimura, Shin Aoki, Hayato Ohwada
CIBCB3
2017 Parallel Inductive Logic Programming System for Superlinear Speedup
Hiroyuki Nishiyama, Hayato Ohwada
ILP2
2017 Special issue on inductive logic programming
Katsumi Inoue, Hayato Ohwada, Akihiro Yamamoto
Mach. Learn.2
2016 Inductive Logic Programming: Challenges
abstract
An overview of notable ILP areas, focusing on three invited talks at ILP 2015, two best student papers and the panel discussion on "ILP 25 Years".
Katsumi Inoue, Hayato Ohwada, Akihiro Yamamoto
AAAI2
2016 Improving Behavior Prediction Accuracy by Using Machine Learning for Agent-Based Simulation
Shinji Hayashi, Niken Prasasti, Katsutoshi Kanamori, Hayato Ohwada
ACIIDS (1)4
2016 Recursive Ensemble Land Cover Classification with Little Training Data and Many Classes
Yu Oya, Katsutoshi Kanamori, Hayato Ohwada
ACIIDS (1)3
2016 Various Classifiers to Investigate the Relationship Between CSR Activities and Corporate Value
Ratna Hidayati, Katsutoshi Kanamori, Hayato Ohwada
IEA/AIE4
2016 Combining Feature Selection with Decision Tree Criteria and Neural Network for Corporate Value Classification
Ratna Hidayati, Katsutoshi Kanamori, Hayato Ohwada
PKAW4
2015 ILP based screening applied to predicting carbonic anhydrase II ligands
abstract
Machine learning has been often used for drug discovery in recent years. Inductive logic programming (ILP), that can express common features of each data in a qualitative, is one of the machine learning methods. The advantage of ILP is that the classification model is clear compared with other machine learning methods such as Support Vector Machine (SVM) because ILP classifies inhibitors using generated rules. ILP is allowed to learn structure of the compounds so that we can draw the common structure of the ligands from the generated rules. In this method, the data of ligands and decoys are collected from “A Database of Useful Decoys: Enhanced” (DUD-E). ILP provides classification model called a rule by learning these data. This study applies the ILP algorithm to the virtual screening of inhibitors of carbonic anhydrase II (CAH2). We demonstrate its performance by classifying ligands and decoys which aren't included in DUD-E. Our results show that ILP has the performance equivalent to SVM which is known for its high classification performance. In addition, this paper shows that ILP can derive rules explaining structural features of CAH2 ligands. Several of these rules are consistent with known property of CAH2 ligand. This paper demonstrate that ILP has high classification performance and clear classification model. Our method is useful for generating rules for ligand design.
Tadasuke Ito, Masato Okada, Shotaro Togami, Shinya Ariyasu, Shin Aoki, Hayato Ohwada
BIBM6
2015 Prediction of radioprotectors targeting p53 for suppression of acute effect of cancer radiotherapy using machine learning
abstract
Radiation therapy and some chemotherapeutic agents mainly target the DNA of growing cancer cells, whereas these therapies have adverse side effects, including p53-induced apoptosis of normal tissues and cells. It is considered that p53 would be a target for therapeutic and mitigative radioprotection to escape from the apoptotic fate. So far, only three radioprotective p53 inhibitors have been reported, namely, pifithrin-α (PFTα), pifithrin-μ (PFTμ), and sodium orthovanadate (vanadate), which protect mice from acute lethality due to hematopoietic syndrome, indicating that pharmacologically temporary suppression of p53 effectively minimize the radiation damage. In this study, we examined the inhibitory activity of some zinc(II) chelators against radiation-induced apoptosis of MOLT-4 cells, based on the assumption that the binding of these compounds to zinc(II) in p53 proteins or removal of zinc(II) from the protein would temporally inhibit the function of p53. However, we have had some problems. The development of drug has been slow, due to the time required and the high cost of screening candidate compounds. It is possible to efficiently search for drugs by using machine learning. So we predict compounds that radioprotectors using Random Forest to study compound futures and using other machine learning methods for comparison with Random Forest. Procedure of learning is as follows: First, compounds were divided into several groups based on the toxicity and protection capability. Next, it was performed classification using machine learning. These results may contribute to discover of new radioprotectors.
Atsushi Matsumoto, Tadasuke Ito, Yurie Nishi, Tatsuro Teraoka, Shin Aoki, Hayato Ohwada
BIBM6
2014 Customer Lifetime Value and Defection Possibility Prediction Model Using Machine Learning: An Application to a Cloud-Based Software Company
Niken Prasasti, Masato Okada, Katsutoshi Kanamori, Hayato Ohwada
ACIIDS (2)4
2014 Utilizing Customers' Purchase and Contract Renewal Details to Predict Defection in the Cloud Software Industry
Niken Prasasti, Katsutoshi Kanamori, Hayato Ohwada
PKAW3
2012 Identifying Driver's Cognitive Load Using Inductive Logic Programming
Fumio Mizoguchi, Hayato Ohwada, Hiroyuki Nishiyama, Hirotoshi Iwasaki
ILP2
2012 Extraction of How-to Type Question-Answering Sentences Using Query Sets
Kyohei Ishikawa, Hayato Ohwada
PKAW2
2012 Identifying Important Factors for Future Contribution of Wikipedia Editors
Yutaka Yoshida, Hayato Ohwada
PKAW2
2011 Toward Finding Semantic Relations not Written in a Single Sentence: An Inference Method using Auto-Discovered Rules
Masaaki Tsuchida, Kentaro Torisawa, Stijn De Saeger, Jong-Hoon Oh, Jun'ichi Kazama, Chikara Hashimoto, Hayato Ohwada
IJCNLP7
2010 Shill Bidder Detection for Online Auctions
Tsuyoshi Yoshida, Hayato Ohwada
PRICAI2
2008 ItemSpider: Social Networking Service That Extracts Personal Character from Individual's Book Information
Tetsuya Tsukamoto, Hiroyuki Nishiyama, Hayato Ohwada
PKAW3
2005 Detecting and Revising Misclassifications Using ILP
Masaki Yokoyama, Tohgoroh Matsui, Hayato Ohwada
Discovery Science3
2003 Integrating information visualization and retrieval for WWW information discovery
Hayato Ohwada, Fumio Mizoguchi
Theor. Comput. Sci.1
2000 Integrating Information Visualization and Retrieval for Discovering Internet Sources
Hayato Ohwada, Fumio Mizoguchi
Discovery Science1
2000 Concurrent Execution of Optimal Hypothesis Search for Inverse Entailment
Hayato Ohwada, Hiroyuki Nishiyama, Fumio Mizoguchi
ILP1
1999 Parallel Execution for Speeding Up Inductive Logic Programming Systems
Hayato Ohwada, Fumio Mizoguchi
Discovery Science1
1999 Smart Office Robot Collaboration Based on Multi-Agent Programming
Fumio Mizoguchi, Hiroyuki Nishiyama, Hayato Ohwada, Hironori Hiraishi
Artif. Intell.3
1998 Incorporating a Navigation Tool into a WWW Browser
Hiroshi Sawai, Hayato Ohwada, Fumio Mizoguchi
Discovery Science2
1998 Web-based communication and control for multiagent robots
abstract
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.
Hironori Hiraishi, Hayato Ohwada, Fumio Mizoguchi
IROS2
1998 Logic specifications for multiple robots based on a current programming language
abstract
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.
Hiroyuki Nishiyama, Hayato Ohwada, Fumio Mizoguchi
IROS2
1998 Time-Constrained HeuristicSearch for Practical Route Finding
Hironori Hiraishi, Hayato Ohwada, Fumio Mizoguchi
PRICAI2
1998 Towards Agent-Oriented Smart Office Based on Concurrent Logic Languages
Hiroyuki Nishiyama, Hayato Ohwada, Fumio Mizoguchi
PRICAI2
1998 Learning First-Order Rules from Image Applied to Glaucoma Diagnosis
Hayato Ohwada, Makiko Daidoji, Shiroaki Shirato, Fumio Mizoguchi
PRICAI1