研究者業績

武藤 佳恭

タケフジ ヨシヤス  (Takefuji Yoshiyasu)

基本情報

所属
武蔵野大学 データサイエンス学部 教授
学位
工学(慶應義塾)
工学(Keio University)

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

外部リンク

論文

 814
  • Yoshiyasu Takefuji
    Journal of Hazardous Materials 488 2025年5月5日  査読有り
    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 2025年5月  査読有り
    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 2025年4月  査読有り
    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 2025年3月13日  査読有り
    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
  • Yoshiyasu Takefuji
    Applied Catalysis B: Environmental 368 2025年7月5日  
    Chen et al. have advanced the theoretical design of dual-site metallo-covalent organic frameworks for enhancing CO2 photoreduction into C2H4 using various machine learning algorithms. While they demonstrated high predictive accuracy using a stacking approach with seven selected algorithms, this study emphasizes the potential biases in feature importance derived from these models. It argues for the necessity of computing unbiased feature importances and highlights the complications posed by different methodologies across models. Further, it recommends robust statistical techniques, such as Spearman's correlation and Kendall's tau, to improve interpretability and validity. Addressing collinearity through Variance Inflation Factor (VIF) analysis is also crucial. These steps aim to deepen understanding and optimize machine learning applications for carbon capture and utilization.
  • Haoqian Pan, Yoshiyasu Takefuji
    International Journal of Cardiology 430 2025年7月1日  
  • Yoshiyasu Takefuji
    Coordination Chemistry Reviews 534 2025年7月1日  
    Liu et al. conducted an insightful investigation into feature importance analysis for predicting CH4 adsorption isotherms in metal–organic frameworks (MOFs), revealing key geometric features that influence model predictions. While their use of advanced machine learning techniques, including neural networks and extra tree regression (ETR), achieved notable accuracy, concerns arise regarding the model-specific biases in feature importance metrics. This paper critically evaluates these metrics, highlighting the risks of misinterpretation due to the lack of ground truth validation. We advocate for the adoption of bias-free statistical methods, such as Spearman's rank correlation and Kendall's tau, which offer a more reliable framework for assessing feature importance. Implementing these approaches could enhance the understanding of gas–solid interactions and improve the reliability of machine learning applications in this domain.
  • Yoshiyasu Takefuji
    Coordination Chemistry Reviews 534 2025年7月1日  
    This paper addresses the critical importance of accurate analysis in research, emphasizing the necessity of error-free and unbiased calculations. While ground truth values are pivotal for validating accuracy, their absence poses challenges in feature importance, feature selection, and clustering methods commonly used in machine learning. Liu et al. have introduced innovative models targeting gas-solid interactions, but their reliance on model-specific methodologies raises concerns about potential biases and erroneous conclusions. This study advocates for robust statistical validation techniques, including the application of Variance Inflation Factor (VIF), Spearman's correlation, and Kendall's tau, to enhance the reliability of feature selection and ensure more accurate insights. By emphasizing a rigorous approach to statistical significance, this paper aims to improve the interpretability and effectiveness of machine learning applications in this specialized field.

書籍等出版物

 41

講演・口頭発表等

 67

担当経験のある科目(授業)

 22

共同研究・競争的資金等の研究課題

 6

社会貢献活動

 21