Curriculum Vitaes

Takefuji Yoshiyasu

  (武藤 佳恭)

Profile Information

Affiliation
Professor, Faculty of Data Science, Musashino University
Degree
工学(慶應義塾)
工学(Keio University)

ORCID ID
 https://orcid.org/0000-0002-1826-742X
J-GLOBAL ID
200901071616096705
researchmap Member ID
5000069498

External link

Papers

 813
  • Yoshiyasu Takefuji
    Journal of Hazardous Materials, 488, May 5, 2025  Peer-reviewed
    This paper outlines key machine learning principles, focusing on the use of XGBoost and SHAP values to assist researchers in avoiding analytical pitfalls. XGBoost builds models by incrementally adding decision trees, each addressing the errors of the previous one, which can result in inflated feature importance scores due to the method's emphasis on misclassified examples. While SHAP values provide a theoretically robust way to interpret predictions, their dependence on model structure and feature interactions can introduce biases. The lack of ground truth values complicates model evaluation, as biased feature importance can obscure real relationships with target variables. Ground truth values, representing the actual labels used in model training and validation, are crucial for improving predictive accuracy, serving as benchmarks for comparing model outcomes to true results. However, they do not ensure real associations between features and targets. Instead, they help gauge the model's effectiveness in achieving high accuracy. This paper underscores the necessity for researchers to recognize biases in feature importance and model evaluation, advocating for the use of rigorous statistical methods to enhance the reliability of analyses in machine learning research.
  • Yoshiyasu Takefuji
    Journal of Industrial Information Integration, 45, May, 2025  Peer-reviewed
    Gomez-Flores et al. proposed a Long Short-Term Memory Neural Network (LSTM-NN) for predicting the flotation behavior of battery active materials using various physicochemical and hydrodynamic variables. While they achieved high prediction accuracy, validated through Mean Relative Error (MRE) and Mean Squared Error (MSE) metrics, concerns arise regarding the integrity of feature importance assessments derived from SAGE and SHAP methodologies. Specifically, the reliance on these model-specific techniques can introduce biases, obscuring the true relationships between features. Additionally, while Spearman's correlation elucidated significant relationships among variables, the absence of discussion on p-values left gaps in interpretation. This study emphasizes the need for cautious interpretation of feature importance metrics and the elimination of less significant variables, aiming to enhance model robustness and improve actionable insights in machine learning contexts.
  • Yoshiyasu Takefuji
    Cities, 159, Apr, 2025  Peer-reviewed
    This study analyzes trends in felony sentence disparity based on gender and race from 2010 to 2024. It utilizes a generative AI to create Python code for data visualization and employs three statistical methods (ANOVA, Chi-Square, Fisher's Exact) to assess p-values. The p-value signifies the probability of random chance causing the observed association. A significance level of 0.05 is used as a benchmark. The evidence-based analysis reveals a concerning trend: increasing disparities in sentences across genders and races. The findings highlight the need for further research and policy changes to address these disparities in the criminal justice system. The paper offers a novel visualization approach to depict these trends, aiding comprehension of the issue.
  • Yoshiyasu Takefuji
    World Medical & Health Policy, Mar 13, 2025  Peer-reviewed
    Cultural norms and traditional behaviors have significantly influenced the outcomes of the COVID-19 pandemic. Asian countries initially outperformed their Western counterparts due to their cultural practices. However, policy shifts have led to a decline in these countries' performance. The objective of this study is to scrutinize the performance of different countries in managing the COVID-19 pandemic, with a focus on the influence of cultural norms and traditional behaviors, and to propose a tool that can inform and enhance current urban management policies. This study employs a time-series policy outcome analysis tool that operates on a single metric: the daily cumulative mortality of the population. By implementing a test-isolation strategy to manage quarantine periods, this tool aims to significantly influence the pandemic's outcome. The tool's efficacy is showcased through a case study involving four countries. New insights are validated and visualized via generated graphs, demonstrating the potential of this tool in the realm of tourism and urban management. This proposed tool holds promise for informing and enhancing current urban management policies, thereby mitigating unnecessary tourism-related fatalities in future pandemics. It underscores the importance of having the right information at the right time to make informed decisions in response to a pandemic.

Misc.

 198

Books and Other Publications

 41

Teaching Experience

 22

Research Projects

 6

Social Activities

 21