skojaku.github.io

• CV
• Google Scholar

Preprints

1. Isabel Constantino, Sadamori Kojaku, Santo Fortunato, Yong-Yeol Ahn. Representing the Disciplinary Structure of Physics: A Comparative Evaluation of Graph and Text Embedding Methods.
   • [Preprint]
2. Sadamori Kojaku, Yong-Yeol Ahn, Filippo Radicchi, Santo Fortunato. Network community detection via neural embeddings.
   • [Preprint]

Journal papers and conference proceedings (refereed)

1. Dakota Murray, Jisung Yoon, Sadamori Kojaku, Rodrigo Costas, Woo-Sung Jung, Staša Milojević, Yong-Yeol Ahn. Unsupervised embedding of trajectories captures the latent structure of mobility.
   • [Paper], [Preprint]
2. Sadamori Kojaku, Jisung Yoon, Isabel Constantino, and Yong-Yeol Ahn. Residual2Vec: Debiasing graph embedding with random graphs. NeurIPS (2021).
   • [Preprint], [Code]
3. Sadamori Kojaku, Giacomo Livan, and Naoki Masuda. Detecting citation cartels in journal networks. Scientific Reports. 11, 14524 (2021).
   • [Preprint, [Code]
4. Sadamori Kojaku, Laurent Hébert-Dufresne, Enys Mones, Sune Lehmann, Yong-Yeol Ahn. The effectiveness of backward contact tracing in networks. Nature Physics (2021).
   • [Paper], [Preprint], [ Code ]
5. Sadamori Kojaku, Naoki Masuda. Constructing networks by filtering correlation matrices: A null model approach, Proceedings of the Royal Society A, 475, 2231 (2019).
   • [Paper], [Preprint], [ Python code ]
6. Sadamori Kojaku, Mengqiao Xu, Haoxiang Xia, Naoki Masuda. Multiscale core-periphery structure in a global liner shipping network. Scientific Reports, 9, 404 (2019)
   • [Paper], [Preprint], [Python code].
7. Sadamori Kojaku, Giulio Cimini, Guido Caldarelli, Naoki Masuda. Structural changes in the interbank market across the financial crisis from multiple core-periphery analysis. Journal of Network Theory in Finance, 4, 33-51 (2018)
   • [Paper], [Preprint]
8. Naoki Masuda, Sadamori Kojaku, Yukie Sano. A configuration model for correlation matrices. Physical Review E, 98, 012312 (2018)
   • [Paper], [Preprint], [MATLAB code]
9. Sadamori Kojaku, Naoki Masuda. A generalised significance test for individual communities in networks. Scientific Reports, 8, 7351 (2018)
   • [Paper], [Preprint], [Python code]
10. Sadamori Kojaku, Naoki Masuda. Core-periphery structure requires something else in the network. New Journal of Physics, 20, 043012 (2018)
    • [Paper], [Preprint], [Code: C++, MATLAB and Python code]
11. Sadamori Kojaku, Naoki Masuda. Finding multiple core-periphery pairs in networks. Physical Review E, 96, 052313 (2017)
    • [Paper], [Preprint], [MATLAB code]
12. Sadamori Koujaku, Ichigaku Takigawa, Mineichi Kudo and Hideyuki Imai. Dense core model for cohesive subgraph discovery. Social Networks, 44, 143-152 (2016)
    • [Paper]

13. Sadamori Koujaku, Mineichi Kudo, Ichigaku Takigawa and Hideyuki Imai. Community change detection in dynamic networks in noisy environment. 24th International Conference on World Wide Web. Florence, Italy, May 18 - 22 (2015)

14. Sadamori Koujaku, Mineichi Kudo, Ichigaku Takigawa and Hideyuki Imai. Structual change point detection for social networks. The World Congress on Engineering. London, the United Kingdom, July 3-5 (2013)

15. 幸若 完壮, 渡辺 浩太, 五十嵐 一. 合理的な忘却型Profit Sharing強化学習法. 電気学会論文誌Ｃ, 132, 448-454 (2012)
    • [Paper]
16. Sadamori Koujaku, Kota Watanabe and Hajime Igarashi. Adaptive profit sharing reinforcement learning for dynamic environment. 10th International Conference on Machine Learning and Applications and Workshops. Hawaii, the United States (2011)

Commentary

1. 幸若 完壮. 埋め込み法が拓くネットワーク科学の新展開. 特集号「複雑ネットワーク研究の最前線」 システム制御情報学会論文誌, 65, 5, 185-191 (2021).

Oral presentations and posters (refereed)

1. Sadamori Kojaku, Clara Boothby, Filipi Nascimento Silva, Attila Varga, Xiaoran Yan, Staša Milojević, Alessandro Flammini, Filippo Menczer, and Yong-Yeol Ahn. Mapping Scientific Foraging. ICSSI. Washinton D.C., USA, 6-9 June (2022)

2. Sadamori Kojaku, Xiaoran Yan, Jisung Yoon, Filipi N. Silva, Vincent Lariviere, and Yong-Yeol Ahn. ICSSI. Washinton D.C., USA, 6-9 June (2022)

3. Sadamori Kojaku, Attila Varga, Xiaoran Yan, Filipi N. Silva, Staša Milojević, Alessandro Flammini, and Yong-Yeol Ahn. The landscape of the COVID-19 research: A neural embedding approach. Netsci. Rome, Italy, 17-25 September (2020)

4. Sadamori Kojaku, Giacomo Livan, and Naoki Masuda. Detecting citaion cartels in journal networks. Netsci. Rome, Italy, 17-25 September (2020)

5. Sadamori Kojaku ネットワークコアの検出アルゴリズムとその応用. ネットワーク科学セミナー. 統計数理研究所. 8.28-30 (2019)

6. Sadamori Kojaku and Naoki Masuda. Constructing networks from correlation matrices: An application to economical data. Threshold Networks. Nottingham 22-24 July (2019) [poster]

7. Sadamori Kojaku, Giulio Cimini, Guido Caldarelli, Naoki Masuda. Structural changes in the interbank market across the financial crisis from multiple core-periphery analysis. Netsci. Vermont, U.S., May 26-31 (2019) [slide]

8. Sadamori Kojaku and Naoki Masuda. A generalised significance test for individual communities in networks. Netsci. Paris, France, June 11–15 (2018)

9. Xia Cui, Sadamori Kojaku, Naoki Masuda and Danushka Bollegala. Solving feature spareness in text classification using core-periphery decomposition. In Proceedings of the 7th Joint Conference on Lexical and Computational Semantics, 225-264 (ACL, New Orleans, USA, 2018)

10. Sadamori Kojaku and Naoki Masuda. Core-periphery structure in degree-heterogeneous networks. Netsci-X. Hangzhou, China (2018)

11. Sadamori Kojaku and Naoki Masuda. Multi-scale organisation of core-periphery structure in networks. 1st Laten American Conference on Complex Networks. Puebla, Mexico September 25-29 (2017) [poster]

12. Sadamori Kojaku and Naoki Masuda. Core-periphery structure of networks: Consideration for random heterogeneous networks. Netsci. Indianapolis, Indiana, USA (2017) [poster]

13. Sadamori Kojaku and Naoki Masuda. An extension of modularity for finding multiple core/periphery structure in networks. Netsci-X. Tel Aviv, Israel January 15-18 (2017) [poster]

14. Sadamori Kojaku and Naoki Masuda. Finding multiple core-periphery structure with random walks. 5th International Workshop on Complex Networks and their Applications. Milan, Italy November 30-December 2 (2016)

15. Keigo Kimura, Mineichi Kudo, Lu Sun and Sadamori Kojaku. Fast random k-labelsets for large-scale multi-label classification. 23rd International Conference on Pattern Recognition. Cancun, Mexico December 4-8 (2016)

Invited talk

1. Sadamori Kojaku. Distilling rich but crude scholarly data using representation learning, IUNI Lunch Colloquium: Science of Science and Networks, Indiana, USA, 28 Oct (2022)
2. Sadamori Kojaku. Residual2Vec: Debiasing graph embedding with random graphs. Network Inequality, NetSci 2022, Shanghai, China, 21 July (2022)
3. Sadamori Kojaku. The effectiveness of backward contact tracing in networks. The State University of New York at Buffalo, 06.04 (2021)
4. *幸若完壮 ネットワークコアの検出アルゴリズムとその応用. ネットワーク科学セミナー. 統計数理研究所. 8.28-30 (2019)

Awards

1. NetSci X Best Contribution on Financial Networks Award for “An extension of modularity for finding multiple core/periphery structure in networks” (2017)
2. Deans’ Award for my doctoral thesis “Finding core communities in social networks.” (2015)
3. Best Student Award for Sadamori Koujaku, Mineichi Kudo, Ichigaku Takigawa and Hideyuki Imai “Structural change point detection for evolutional networks.” The World Congress on Engineering (2013)

Grant

• Sadamori Kojaku, Giulio Cimini, Guido Caldarelli, Daigo Uemoto, and Takashi Kamihigashi. Correlation-based reconstruction of financial networks for systemic risk control. JSPS二国間交流事業 2020. (海外転出のため辞退)

Patents

• 幸若完壮／上東貴志。学術論文の査読者検索装置、査読者検索方法、及び査読者検索プログラム [特願2020-14904] (English translation: Reviewer search method, program, and device for academic papers).
• Prediction method, prediction system and program [Patent No: 9087294]

Referee activities

1. Nature Human Behavior
2. Nature Communications
3. Journal of Complex Networks
4. Journal of Computational Social Science
5. PLOS ONE
6. Scientific Reports
7. PeerJ