Kotake, Naohiko



Graduate School of System Design and Management (Hiyoshi)



E-mail Address

E-mail address

Related Websites

Career 【 Display / hide

  • 2021.04

    Keio Yokohama Elementary School

  • 2018.04

    慶應義塾大学大学院システムデザイン・マネジメント研究科 教授

  • 2011.04

    慶應義塾大学大学院システムデザイン・マネジメント研究科 准教授

  • 2009.04

    慶應義塾大学先導研究センター 特別研究准教授

  • 1998.04

    Japan Aerospace Exploration Agency

Academic Background 【 Display / hide

  • 2005.09

    Keio University, 政策・メディア研究科

    Graduate School, Completed, Doctoral course

  • 1998.03

    Keio University, Graduate School, Division of Science and Engineering, 計算機科学専攻

    Graduate School, Completed, Master's course

  • 1996.03

    Keio University, Faculty of Science and Engineering, 電気工学科

    University, Graduated

Academic Degrees 【 Display / hide

  • 博士(政策・メディア), Keio University, 2005.09


Books 【 Display / hide

  • システムデザイン・マネジメントとは何か

    KOHTAKE Naohiko, 慶應義塾大学出版会, 2016.11

  • アイディアソとハッカソンで未来をつくろう

    KOHTAKE Naohiko, インプレスR&D, 2015.11

  • CanSatカンサット ―超小型模擬人工衛星―

    KOHTAKE Naohiko, オーム社, 2014.08

  • 位置情報ビッグデータ ウェアラブルコンピューティング時代を切り拓く

    KOHTAKE Naohiko, インプレスR&D, 2014.03

  • エンジニアリング システムズ 複雑な技術社会において人間のニーズを満たす

    KOHTAKE Naohiko, 慶応義塾大学出版会, 2014.02

Papers 【 Display / hide

  • Comparison of profit-based multi-objective approaches for feature selection in credit scoring

    Simumba N., Okami S., Kodaka A., Kohtake N.

    Algorithms (Algorithms)  14 ( 9 )  2021.09

     View Summary

    Feature selection is crucial to the credit-scoring process, allowing for the removal of irrel-evant variables with low predictive power. Conventional credit-scoring techniques treat this as a separate process wherein features are selected based on improving a single statistical measure, such as accuracy; however, recent research has focused on meaningful business parameters such as profit. More than one factor may be important to the selection process, making multi-objective optimization methods a necessity. However, the comparative performance of multi-objective methods has been known to vary depending on the test problem and specific implementation. This research employed a recent hybrid non-dominated sorting binary Grasshopper Optimization Algorithm and compared its performance on multi-objective feature selection for credit scoring to that of two pop-ular benchmark algorithms in this space. Further comparison is made to determine the impact of changing the profit-maximizing base classifiers on algorithm performance. Experiments demon-strate that, of the base classifiers used, the neural network classifier improved the profit-based measure and minimized the mean number of features in the population the most. Additionally, the NSBGOA algorithm gave relatively smaller hypervolumes and increased computational time across all base classifiers, while giving the highest mean objective values for the solutions. It is clear that the base classifier has a significant impact on the results of multi-objective optimization. Therefore, careful consideration should be made of the base classifier to use in the scenarios.

  • Influential factors on aerosol change during covid-19 in ayutthaya, thailand

    Kodaka A., Leelawat N., Onda Y., Tang J., Laosunthara A., Saengtabtim K., Sochoeiya P., Kohtake N.

    Engineering Journal (Engineering Journal)  25 ( 8 ) 187 - 196 2021.08

    ISSN  01258281

     View Summary

    Various interventions were made by the Thai government to prevent the COVID-19 spread by controlling socioeconomic activities, but the effectiveness of these interventions and other factors have not yet been fully clarified. Thus, this study aims to provide further scientific evidence on those potential factors which affect the socioeconomic activities changes during the pandemic, by using spatial analysis on atmospheric composition. By taking Phra Nakhon Si Ayutthaya Province, Thailand as the case area. Results of the government's COVID-19 measures and statuses of industries were compared with changes in aerosols, including PM 2.5 which was analyzed by Google Earth Engine with nine open datasets including meteorological and hydrological factors. The analysis revealed that the aerosol index in ueban area of the province decreased at 28.03% in 2020 compared in 2019. Besides, PM 2.5 drastically decreased from March 2020, even without the influence of wind speed which as the highest causal relationship, and kept low level compared with previous years. The reason of the tendency would be explained that other than government interventions including national-level state of the emergency decree, reduction of factories’ activities at Rojana Industrial Park and reduction of the number of tourists had significant influence to reduce the mean value of PM 2.5.

  • Spatiotemporal integration of mobile, satellite, and public geospatial data for enhanced credit scoring

    Simumba N., Okami S., Kodaka A., Kohtake N.

    Symmetry (Symmetry)  13 ( 4 )  2021.04

     View Summary

    Credit scoring of financially excluded persons is challenging for financial institutions because of a lack of financial data and long physical distances, which hamper data collection. The remote collection of alternative data has the potential to overcome these challenges, enabling credit access for such individuals. Whereas alternative data sources such as mobile phones have been investigated by previous researchers, this research proposes the integration of mobile-phone, satellite, and public geospatial data to improve credit evaluations where financial data are lacking. An approach to integrating these disparate data sources involving both spatial and temporal analysis methods such as spatial aggregation was employed, resulting in various data combinations. The resulting data sets were used to train classifiers of varying complexity, from logistic regression to ensemble learning. Comparisons were based on various performance metrics, including accuracy and the area under the receiver operating-characteristic curve. The combination of all three data sources performed significantly better than mobile-phone data, with the mean classifier accuracy and F1 score improving by 18% and 0.149, respectively. It is shown how these improvements can translate to cost savings for financial institutions through a reduction in misclassification errors. Alternative data combined in this manner could enhance credit provision to financially excluded persons while managing associated risks, leading to greater financial inclusion.

  • Government COVID-19 Responses and Subsequent Influences on NO<inf>2</inf>Variation in Ayutthaya, Thailand

    Kodaka A., Leelawat N., Tang J., Onda Y., Kohtake N.

    2021 2nd International Symposium on Instrumentation, Control, Artificial Intelligence, and Robotics, ICA-SYMP 2021 (2021 2nd International Symposium on Instrumentation, Control, Artificial Intelligence, and Robotics, ICA-SYMP 2021)   2021.01

    ISSN  9781728187600

     View Summary

    The control of economic activities by governments for the purpose of minimizing COVID-19 spread influenced atmospheric conditions. Satellite-based technology is promising to monitor these changes and even non-specialists in geospatial analysis can use it through cloud-based open platforms. This study aims to give scientific interpretation on the causes of the atmospheric changes based on these governmental controls on human activity. The nitrogen dioxide (NO2) levels were monitored in Ayutthaya Province in Thailand in an urban area including industrial zones during January 1 to April 30, 2020. An analysis was conducted with Google Earth Engine by using four datasets including NO2 data from Sentinel-5P. The mean value of NO2 density in 2020 decreased 12.5% compared with that in 2019. The closure of industrial facilities by the government seemed to be a key cause of the phenomena. The decline was statistically tested and resulted in a significant difference between the two periods. As the new daily cases decreased to single digits, the difference became non-significant from May 1, 2020. Single timeseries analysis on NO2 density change enabled visualization of the brief impact of responses and policies made by the government and subsequent economic activities; however, further atmospheric and industrial activity data are required for further assessment.

  • Developmental Experiences Related to Retirement from Sport: Insights from Japan

    Oulevey M., Hirata D., Lavallee D., Kohtake N.

    Journal of Loss and Trauma (Journal of Loss and Trauma)  26 ( 6 ) 576 - 595 2021

    ISSN  15325024

     View Summary

    Psychological support systems for retiring elite athletes can assist them in making career transitions out of sport. The purpose of this study is to further advance research in this area, with a specific focus the developmental experiences related to the sport career transition process in Japan. One retired Olympic medalist was analyzed with a life story analysis method. The findings highlight the psychological difficulties experienced by retiring athletes and the system requirements to help them make an optimal transition.

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Papers, etc., Registered in KOARA 【 Display / hide

Presentations 【 Display / hide

  • Indoor and Outdoor Seamless Positioning using Indoor Messaging System and GPS

    KOHTAKE Naohiko, Shusuke Morimoto, Satoshi Kogure, and Dinesh Manandhar

    2011 International Conference on Indoor Positioning and Indoor Nabigation (Guimarães Portugal.) , 2011.09, Oral Presentation(general)

  • Report on an assessment experience based on ISO/IEC 29110

    Motoko Takeushi, Yumi Koishi, Kazunori Shioya, Seiko Shirasaka, and KOHTAKE Naohiko

    18th EuroSPI Conference (Spain Barcelona) , 2011.06, Oral Presentation(general)

  • Introduction of Systems Engineering to Cansat Project – Construction of PBL-type Educational Program -

    Hiraku Sakamoto,KOHTAKE Naohiko, Seiko Shirasaka, Koji Yamada, Yuya Sudo, Shuhei Toki, and Yuya Kakehashi,

    28th International Symposium on Space Technology and Science (沖縄) , 2011.06, Oral Presentation(general)

  • Practical Application of Systems Engineering to Cansat Project – Operation of PBL-type Educational Program in Seven Universities –

    huhei Toki, Yuya Kakehashi, Hiraku Sakamoto, KOHTAKE Naohiko, and Seiko Shirasaka

    28th International Symposium on Space Technology and Science (沖縄) , 2011.06, Oral Presentation(general)

  • Structure of Sub-orbital Flight for both Cargo Delivery and Space Tourism in East Asia

    Aria Iwasawa, Benie Shigaki, Shusuke Morimoto, Yoshikazu Tomita, KOHTAKE Naohiko, Hajime Yano, Yoshiaki Ohkami,

    28th International Symposium on Space Technology and Science (沖縄) , 2011.06, Oral Presentation(general)

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Research Projects of Competitive Funds, etc. 【 Display / hide

  • Credit Scoring System to Resolve Financial Exclusion of Small-Scale Farmers in Developing Countries by Mobile and Satellite Data


    MEXT,JSPS, Grant-in-Aid for Scientific Research, 神武 直彦, Grant-in-Aid for Scientific Research (B), Principal Investigator

  • Development of Open Platform for Providing Indoor and Outdoor Seamless Location-Based Services


    MEXT,JSPS, Grant-in-Aid for Scientific Research, 神武 直彦, Grant-in-Aid for Scientific Research (C), Principal Investigator

     View Summary

    We developed “Open Platform for Providing Indoor and Outdoor Seamless Location-Based Services” in this research. The purpose of this research is to make it possible to provide location-based service indoor and outdoor seamlessly.First of all, the requirements were clarified together with stakeholders for railway stations, commercial facilities, and sports facilities that may be users of this platform. Second, we applied the position sensor such as GPS, Quasi-Zenith Satellite, BLE, Geospatial Information Infrastructure, Real-Time Kinematic and so on, and confirmed the usefulness of collecting, analyzing and visualizing location information without being conscious of indoor and outdoor. Finally, we collaborate with local government officials and others, and confirmed the effectiveness of this platform that can provide location information service without specialized technology.

Works 【 Display / hide

  • (講演)宇宙技術と測位技術,関西宇宙イニシアチブKaSpiセミナー

    KOHTAKE Naohiko



    Other, Single

  • (講演)大規模・複雑システムの構築と運用をリードする人材の育成,科学技術振興機構研究開発戦略センター システム科学技術推進委員会

    KOHTAKE Naohiko



    Other, Single

  • (講演)宇宙技術×情報技術=∞,文部科学省先導的ITスペシャリスト育成推進プログラム

    KOHTAKE Naohiko



    Other, Single


Courses Taught 【 Display / hide











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Committee Experiences 【 Display / hide

  • 2018.11

    監査諮問委員会, 一般財団法人 日本IT団体連盟

  • 2018.10

    日吉キャンパス公開講座運営委員, 大学教養研究センター

  • 2018.10

    日吉学企画委員, 大学教養研究センター

  • 2018.09

    選考委員, 一般財団法人髙島科学技術振興座員団

  • 2018.08

    Adjunct Professor, Asian Institute of Technology

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