Profile Information
- Affiliation
- Senior Administrator, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency
- Degree
- Ph.D.(Feb, 1998, Keio University)
- ORCID ID
https://orcid.org/0000-0003-4984-4063- J-GLOBAL ID
- 202401002593478317
- researchmap Member ID
- R000065182
I am a Professor at Keio University, affiliated with the Graduate School of Media and Governance and the Faculty of Science and Technology. I earned my bachelor’s degree from the University of Tsukuba in 1984 and later completed my Ph.D. in Quantum Optics at Keio University in 1998.
My career spans several prominent companies: I spent five years at Sharp Corporation, eleven years at Fuji Xerox, three and a half years at Samsung Electronics, and twenty years at Toppan Holdings before joining Keio University in December 2023. Until 2015, my research focused on photonics, quantum optics, and semiconductor/microfabrication. Since 2013, I have expanded my work to include computer vision (optical metrology) and machine learning, and as of 2018, my primary focus has shifted to quantum information (quantum machine learning and quantum optics). My developed products include TFT-driven printer heads, lens sheets for rear-projection televisions, and microneedles.
Academic Activities: IEEE Senior Member (Computer Society, Photonics Society), Japanese Society for Artificial Intelligence (JSAI), Japan Society of Applied Physics, Optical Society of Japan.
Committee Activities: Quantum AI and Optimization (QAIO;ICCART), International display workshop (IDW) of International conferences. Additionally, AI Map (JSAI), IEEE Standard (P3120)
Research Interests
4Research Areas
3Research History
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Apr, 2026 - Present
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Jan, 2024 - Mar, 2026
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Dec, 2023 - Mar, 2026
Education
2Committee Memberships
5-
May, 2024 - Present
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Oct, 2020 - Present
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Apr, 2009 - Present
Papers
42-
Advanced Quantum Technologies, 9(2), Feb 10, 2026 Peer-reviewedLast authorCorresponding authorABSTRACT This study formulates a novel, elevation‐aware Quadratic Unconstrained Binary Optimization (QUBO) model for multi‐vehicle route optimization that simultaneously reduces fuel consumption and traffic congestion. Candidate routes are generated using a gradient‐corrected Dijkstra algorithm, and route selection is optimized by minimizing a rigorously constructed QUBO Hamiltonian that incorporates fuel cost, route overlap, and constraint satisfaction. Extensive numerical validation is performed using classical annealing simulations across multiple regions with diverse topographical and road network characteristics, including San Francisco. The results demonstrate that incorporating elevation information significantly reduces fuel consumption, while the proposed overlap penalty effectively mitigates congestion. A clear trade‐off between overlap reduction and fuel efficiency is quantitatively characterized. The mathematical consistency of the formulation is ensured through a theoretically derived penalty coefficient, which guarantees constraint satisfaction and stable optimization behavior. Scaling experiments further reveal the limitations of classical solvers as the number of candidate routes increases, highlighting the importance of robust QUBO formulations and motivating future implementation on quantum processing units. Overall, this work establishes a validated and theoretically sound QUBO framework for sustainable transportation optimization and provides a reliable performance baseline for future quantum hardware–based investigations.
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2025 IEEE 18th International Symposium on Embedded Multicore/Many-core Systems-on-Chip (MCSoC), 494-502, Dec 15, 2025 Peer-reviewed
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2025 IEEE Photonics Conference (IPC), 1-2, Nov 9, 2025 Peer-reviewedLead authorCorresponding author
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2025 IEEE International Conference on Quantum Artificial Intelligence (QAI), 61-66, Nov 2, 2025 Peer-reviewedLead authorCorresponding author
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2025 5th International Conference on Electrical, Computer, Communications and Mechatronics Engineering (ICECCME), 1-6, Oct 16, 2025 Peer-reviewedLast authorCorresponding author
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2025 IEEE International Conference on Quantum Computing and Engineering (QCE), 1776-1784, Aug 30, 2025 Peer-reviewedLead authorCorresponding author
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New Generation Computing, 43(4), Aug 26, 2025 Peer-reviewedLast author
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Proceedings of the 15th International Symposium on Highly Efficient Accelerators and Reconfigurable Technologies, 117-125, May 25, 2025 Peer-reviewed
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EPJ Quantum Technology, 12(1), Mar 21, 2025 Peer-reviewedLead authorCorresponding author
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Discover Electronics, 1(1), Jun 11, 2024 Peer-reviewedLead authorCorresponding authorAbstract Liquid crystal waveguide film that we can control through wide visible wavelength has been proposed. Recently, small optical system is needed for various industrial application. Among the application, liquid crystal is the material for controlling optical ray. The application includes optical switch and display by controlling birefringence. These applications include AR/VR display, for manufacturing, inspection, and so on. In this study, we have investigated liquid crystal (LC) waveguide film that light is emitted from the waveguide film on glasses toward the eye when the power is turned on. The cut-off of waveguide film is based on liquid crystal switch using refractive index anisotropy. We select smart glasses as one of the applications for AR/VR display. The potential of LC waveguide films is demonstrated by simulating the propagation characteristics of waveguides film, LC reorientations, and diffraction gratings in the field of RGB wavelength range. By using the waveguide structure, the film thickness can be configured to be less than 1 mm. We can expect the liquid crystal waveguide has much application to optical integrated circuit as other application except for smart glasses.
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PHM Society Asia-Pacific Conference, 4(1), Sep 4, 2023 Peer-reviewedInvitedLead authorCorresponding authorIn recent years, the diversification of consumer values has led to an increase in the number of small-quantity, high-mix products. For many manufacturing companies, shipping inspections of such products are of great importance. As all products have the same value, good and defective products need to be efficiently identified. Now, a promising future application of quantum technology is considered to be quantum machine learning. We believe that the quantum classifier for SVMs using quantum kernels is one of the areas where quantum advantages can be demonstrated. At present, there are few examples of quantum classifiers applied to real problems in manufacturing processes. In this study, we aim to build a classifier that can demonstrate the quantum advantage and compare SVMs using classical and quantum kernels with conventional ResNet. Initially, a binarised image was generated after image pre-processing. After principal component analysis and dimensionality reduction were performed on the images, SVM with kernels was carried out. The kernel-based SVMs was then compared with the conventionally implemented Residual neural network (ResNet) using an evaluation index: F1-score. The results showed that the F1-score of SVMs using classical kernels was equivalent to that of Resnet. In addition, SVMs using quantum kernels showed higher F1-score than ResNet. In addition, the impact of the feature map and principal components of the quantum kernel was also investigated. It was found that when the feature map became more complex, conversely, circuit generation took more time. It was also found that the principal components are highly relevant to the image and cannot lead to simple results. In the future, we plan to accumulate more experimental data, look for scenes where quantum machine learning can be used and apply it to the manufacturing field.
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Proceedings - 2023 IEEE International Conference on Quantum Computing and Engineering, QCE 2023, 2 385-386, 2023 Peer-reviewedLast authorCorresponding author
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Proceedings - 2023 IEEE International Conference on Quantum Computing and Engineering, QCE 2023, 2 262-263, 2023 Peer-reviewedLead authorCorresponding author
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EPJ Quantum Technology, 9(1), Dec, 2022 Peer-reviewedLead authorCorresponding author
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Proceedings - 2022 IEEE International Conference on Quantum Computing and Engineering, QCE 2022, 818-819, 2022 Peer-reviewedLast authorCorresponding author
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Proceedings - 2022 IEEE International Conference on Quantum Computing and Engineering, QCE 2022, 875-878, 2022 Peer-reviewedLead authorCorresponding author
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Proceedings of the International Display Workshops, 29 297-300, 2022 Peer-reviewedLead authorCorresponding author
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Jul 7, 2021 Last authorVariational Quantum Eigensolver (VQE) method is the way to derive the wave functions from their eigen energies using quantum computers. But, the methods to utilize the superposition states between them haven't been developed yet. The method to calculate the off diagonal element of observables between two states derived by VQE method requires large numbers of gate operations for Noisy Intermediate Scale Quantum (NISQ) devices. We proposed the novel method to drive the superposition state between the states the derived by VQE method. We call it Frame superposition cluster (FSC) method. Using the method, we confirmed that dipole transition moment could be calculated with the highest accuracy compared to other methods.
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Mar 23, 2021 Last authorSubspace-Search Variational Quantum Eigen solver (SSVQE) is a searching method of multiple states and relies on the unitarity of transformations to ensure the orthogonality of output states for multiple states. Therefore, this method is thought to be a promising method for quantum chemistry because ordinary Variational Quantum Eigen solver (VQE) can only calculate the excited states step by step from the ground state based on Variational Quantum deflation (VQD). We compare the advantage of VQE, SSVQE with/without the constraint term and/or Tabu search term, which is added by the Lagrange multiplier method so as to calculate the desired energy levels. We evaluated the advantage by calculating each level of H2 and HeH, respectively. As there simulation results, the accuracy calculated by constrained VQE with Tabu search indicates higher accuracy than that of our other algorithm, for analysis on H2. The accuracy calculated by constrained SSVQE indicates higher that of the constrained VQE with Tabu search . We found it is beneficial for enhancing the accuracy to use constraint terms decreasing convergence times to use Tabu search terms according to the nature of molecules. We demonstrate that constraint and Tabu search terms contribute to the accuracy and convergence time on quantum chemical calculating.
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Proceedings - 2021 IEEE International Conference on Quantum Computing and Engineering, QCE 2021, 437-438, 2021 Peer-reviewedCorresponding author
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IEEE Transactions on Pattern Analysis and Machine Intelligence, 43(2) 638-651, 2021 Peer-reviewedCorresponding author
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International Journal of Energy Research, 43(9) 4967-4975, May 24, 2019 Peer-reviewedLead authorLast authorCorresponding author
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Materials Today Chemistry, 13 79-87, 2019
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Proceedings of the International Display Workshops, 3 1478-1481, 2018
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Microsystem Technologies, 24(9) 3589-3599, 2018
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Proceedings of the IEEE Computer Society Conference on Computer Vision and Pattern Recognition, 2016-December 3774-3782, Dec 9, 2016
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International Journal of Energy Research, 40(15) 2176-2186, 2016
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Optics & Laser Technology, 68 220-224, May, 2015
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Journal of Photopolymer Science and Technology, 28(3) 319-323, 2015
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Proceedings of the International Display Workshops, 1 492-495, 2013
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SID Symposium Digest, 35(1) 846-846, 2004
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Proceedings of SPIE - The International Society for Optical Engineering, 5005 414-421, 2003
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Proceedings of SPIE - The International Society for Optical Engineering, 4660 266-274, 2002
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Jpn. J. Appl. Phys., 39(Part 1, No. 2B) 888-891, Feb, 2000
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Proceedings of SPIE - The International Society for Optical Engineering, 3864 364-366, 1999
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Molecular Crystals and Liquid Crystals Science and Technology Section A: Molecular Crystals and Liquid Crystals, 294-95 255-258, 1997
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Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals, 267(1) 107-116, 1995
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Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals, 227(1) 113-131, 1993
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Journal of Physics D: Applied Physics, 26(8) B217-B220, 1993
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Molecular Crystals and Liquid Crystals Science and Technology Section B: Nonlinear Optics, 3(3) 255-264, 1992
Misc.
2-
Fuji Xerox Technical Report, (12), 1998
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Fuji Xerox Technical Report, (5), 1990
Books and Other Publications
2Presentations
33-
The 73rd JSAP Spring meeting 2026, Mar 15, 2026
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Quantum Techniques in Machine Learning 2024, Nov, 2024
Professional Memberships
6-
Oct, 2018 - Present
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Oct, 2018 - Present
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Apr, 2018 - Present
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Apr, 2016 - Present
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Jan, 2015 - Present