Kikuchi, Shuta

写真a

Affiliation

Graduate School of Science and Technology (Yagami)

Position

Project Assistant Professor (Non-tenured)/Project Research Associate (Non-tenured)/Project Instructor (Non-tenured)

Career 【 Display / hide

  • 2019.04
    -
    2022.12

    Lion Corporation, 研究開発本部 安全性科学研究所, Researcher

  • 2023.01
    -
    2024.03

    Lion Corporation, Research and Development Headquarters Advanced Analytical Science Research Laboratories Microbiological Control Group, Researcher

  • 2024.04
    -
    Present

    Keio University, Graduate School of Science and Technology, Project Assistant Professor

Academic Background 【 Display / hide

  • 2013.04
    -
    2017.03

    Waseda University, School of Advanced Science and Engineering, Department of Life Science and Medical Bioscience

  • 2017.04
    -
    2019.03

    Waseda University, Graduate School of Advanced Science and Engineering, Department of Life Science and Medical Bioscience

  • 2021.04
    -
    2024.03

    Keio University, Graduate School of Science and Technology, School of Fundamental Science and Technology Center for Applied Physics and Phusico-Informatioin

 

Research Areas 【 Display / hide

  • Natural Science / Mathematical physics and fundamental theory of condensed matter physics

  • Life Science / Applied microbiology

  • Informatics / Life, health and medical informatics

  • Environmental Science/Agriculture Science / Environmental impact assessment

Research Keywords 【 Display / hide

  • Ising machine

  • Simulation

  • Network science

  • Microbiology

  • Infection control science

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Papers 【 Display / hide

  • Hybrid Optimization Method Using Simulated-Annealing-Based Ising Machine and Quantum Annealer

    Shuta Kikuchi, Nozomu Togawa, Shu Tanaka

    Journal of the Physical Society of Japan (Journal of the Physical Society of Japan)  92 ( 12 ) 124002 2023.12

    Joint Work, Lead author, Corresponding author, Accepted,  ISSN  00319015

     View Summary

    Ising machines have been developed as fast and highly accurate solvers for combinatorial optimization problems. They are classified based on their internal algorithms, with examples including simulated-annealing-based Ising machines (non-quantum-type Ising machines) and quantum-annealing-based Ising machines (quantum annealers). Herein, we have investigated the performance of a hybrid optimization method that capitalizes on the advantages of both types, utilizing a non-quantum-type Ising machine to enhance the performance of the quantum annealer. In this method, the non-quantum-annealing Ising machine initially solves an original Ising model multiple times during preprocessing. Subsequently, reduced-size sub-Ising models, generated by spin fixing, are solved by a quantum annealer. Performance of the method is evaluated via simulations using Simulated Annealing (SA) as a non-quantum-type Ising machine and D-Wave Advantage as a quantum annealer. Additionally, we investigate the parameter dependence of the hybrid optimization method. The method outperforms the preprocessing SA and the quantum annealer alone in fully connected random Ising models.

  • Dynamical Process of a Bit-Width Reduced Ising Model With Simulated Annealing

    Shuta Kikuchi, Nozomu Togawa, Shu Tanaka

    IEEE Access (IEEE Access)  11   95493 - 95506 2023.08

    Lead author, Corresponding author, Accepted

     View Summary

    Ising machines have attracted attention as efficient solvers for combinatorial optimization problems, which are formulated as ground-state (lowest-energy) search problems of the Ising model. Due to the limited bit-width of coefficients on Ising machines, the Ising model must be transformed into a bit-width reduced (BWR) Ising model. According to previous research, the bit-width reduction method, which adds auxiliary spins, ensures that the ground state of the BWR Ising model is theoretically the same as the Ising model before bit-width reduction (original Ising model). However, while the dynamical process is closely related to solution accuracy, how the BWR Ising model progresses towards the ground state remains to be elucidated. Therefore, we compared the dynamical processes of these models using simulated annealing (SA). Our findings reveal significant differences in the dynamical process across models. Analysis from the viewpoint of statistical mechanics found that the BWR Ising model has two characteristic properties: an effective temperature and a slow relaxation. These properties alter the temperature schedule and spin flip probability in the BWR Ising model, leading to differences in the dynamical process. Therefore, to obtain the same dynamical process as the original Ising model, we proposed SA parameters for the BWR Ising model. We demonstrated the proposed SA parameters using a square lattice Ising model, in which all coefficients were set uniformly to the same positive values or randomly. Our experimental evaluations demonstrated that the dynamical process of the BWR and original Ising model became closer.

  • Characterisation of bacteria representing a novel <i>Nitrosomonas</i> clade: Physiology, genomics and distribution of missing ammonia oxidizer

    Shuta Kikuchi, Hirotsugu Fujitani, Kento Ishii, Rino Isshiki, Yuji Sekiguchi, Satoshi Tsuneda

    Environmental Microbiology Reports (Wiley)  15 ( 5 ) 404 - 416 2023.04

    Lead author, Accepted,  ISSN  1758-2229

  • Genomic and Physiological Characteristics of a Novel Nitrite-Oxidizing Nitrospira Strain Isolated From a Drinking Water Treatment Plant

    Hirotsugu Fujitani, Kengo Momiuchi, Kento Ishii, Manami Nomachi, Shuta Kikuchi, Norisuke Ushiki, Yuji Sekiguchi, Satoshi Tsuneda

    Frontiers in Microbiology (Frontiers Media {SA})  11   545190 2020.09

    Joint Work, Accepted,  ISSN  1664-302X

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

Reviews, Commentaries, etc. 【 Display / hide

  • 最適化問題を高速に解くには?—量子アニーリング技術応用事例—

    田中宗, 菊池脩太, 関優也

    ペトロテック 47 ( 5 ) 289 - 293 2024.05

  • イジングマシンによる大規模組合せ最適化問題の解法を目指した変数固定アルゴリズム

    田中宗, 服部智大, 菊池脩太

    分子シミュレーション学会誌 アンサンブル 25 ( 3 ) 211 - 217 2023.07

    ISSN  1884-6750

Presentations 【 Display / hide

  • 制約付き組合せ最適化問題に対するイジングマシン実機とシミュレーテッドアニーリングのハイブリッド手法の提案

    網野あかね, 服部智大, 菊池脩太, 田中宗

    第11回量子ソフトウェア研究発表会, 

    2024.03

    Oral presentation (general)

  • 小学校における感染リスクの可視化—ウイルス感染拡大要因と効果的な衛生行動の推定—

    菊池脩太, 中島敬祐, 加藤泰輝, 杉山淳一, 瀧沢岳, 柿澤恭史, 向井大誠, 倉橋節也

    日本学校保健学会第69回学術大会, 

    2023.11

    Poster presentation

  • 小学校における感染リスクの可視化—病原体伝播の推定手法の開発と衛生行動の評価—

    瀧沢岳, 菊池脩太, 中島敬介, 加藤泰輝, 杉山淳一, 柿澤恭史, 向井大誠, 倉橋節也

    日本学校保健学会第69回学術大会, 

    2023.11

    Oral presentation (general)

  • イジングマシンにおける整数・バイナリ変換の動的特性

    高橋虎太郎, 菊池脩太, 田中宗

    日本物理学会第78回年次大会, 

    2023.09

    Oral presentation (general)

  • Analysis of hybrid method with quantum annealing machines and simulated-annealing-based Ising machines

    Shuta Kikuchi, Nozomu Togawa, Shu Tanaka

    28th International Conference on Statistical Physics (Statphys28), 

    2023.08

    Poster presentation

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Memberships in Academic Societies 【 Display / hide

  • 日本学校保健学会, 

    2023.04
    -
    2024.03
  • 日本物理学会, 

    2021.11
    -
    Present