Research Papers & Presentations

A collection of papers written by Fixstars engineers and talks given at academic conferences.

2026
Generative AI & LLM Memory Capacity, Not Compute, Bounds Large-MoE Serving: A 15x Latency Reduction on GLM-5.1

Yoshiki Kunimoto

2026 IEEE International Conference on Device Technologies for Diversified Applications (IEEE DTDA 2026)

Conference
Quantum & Combinatorial Optimization Constrained Optimization of Higher-Order Cluster-Expansion Hamiltonians for Alloys Using Simulated Bifurcation

Kazuhide Ichikawa, Satoru Ohuchi, Tomoyasu Yokoyama, Takuma Saito, Yoshiki Matsuda

arXiv

Preprint
Quantum & Combinatorial Optimization Evaluating the Performance of Direct Higher-Order Formulations in Combinatorial Optimization Under Simulated Annealing

Kazuki Ikeuchi, Yoshiki Matsuda, Shu Tanaka

IEEE Access

Journal
HPC & Parallel Computing Efficient Iterative QPE Simulations for Quantum Chemistry using Distributed State-Vector Methods

Wataru Mizukami, Shoma Hiraoka, Sho Nishida, Yusuke Teranishi

NVIDIA GTC 2026

Conference
Quantum & Combinatorial Optimization An Ising machine formulation for design updates in topology optimization of flow channels

Yudai Suzuki, Shiori Aoki, Fabian Key, Katsuhiro Endo, Yoshiki Matsuda, Shu Tanaka, Marek Behr, Mayu Muramatsu

Engineering with Computers

Journal
2025
Quantum & Combinatorial Optimization Evaluating the Performance of Direct Higher-Order Formulations in Combinatorial Optimization Problems

Kazuki Ikeuchi, Yoshiki Matsuda, Shu Tanaka

arXiv

Preprint
Storage & Memory Analysis and Evaluation of Using Microsecond-Latency Memory for In-Memory Indices and Caches in SSD-Based Key-Value Stores

Yosuke Bando, Akinobu Mita, Kazuhiro Hiwada, Shintaro Sano, Tomoya Suzuki, Yu Nakanishi, Kazutaka Tomida, Hirotsugu Kajihara, Akiyuki Kaneko, Daisuke Taki, Yukimasa Miyamoto, Tomokazu Yoshida, Tatsuo Shiozawa

arXiv

Preprint
Quantum & Combinatorial Optimization Formulation of Correction Term in QUBO Form for Phase-Field Model

Shiori Aoki, Katsuhiro Endo, Yoshiki Matsuda, Yuya Seki, Shu Tanaka, Mayu Muramatsu

International Journal for Numerical Methods in Engineering

Journal
Quantum & Combinatorial Optimization A black-box optimization method with polynomial-based kernels and quadratic-optimization annealing

Yuki Minamoto, Yuya Sakamoto

arXiv

Preprint
2024
Quantum & Combinatorial Optimization An Ising Machine Formulation for Design Updates in Topology Optimization of Flow Channels

Yudai Suzuki, Shiori Aoki, Fabian Key, Katsuhiro Endo, Yoshiki Matsuda, Shu Tanaka, Marek Behr, Mayu Muramatsu

arXiv

Preprint
HPC & Parallel Computing Performance Analysis of the NICAM Benchmark on MN-Core Processor

Hikaru Takayashiki, Natsuko Saito, Hiroto Imachi, Ryo Sakamoto, Junichiro Makino

SC24 Workshops (SC24-W)

Conference
HPC & Parallel Computing Doubling Graph Traversal Efficiency to 198 TeraTEPS on the Supercomputer Fugaku

Junya Arai, Masahiro Nakao, Yuto Inoue, Kanto Teranishi, Koji Ueno, Keiichiro Yamamura, Mitsuhisa Sato, Katsuki Fujisawa

SC24 (International Conference for High Performance Computing, Networking, Storage and Analysis)

Conference
Quantum & Combinatorial Optimization Development of optimization method for truss structure by quantum annealing

Rio Honda, Katsuhiro Endo, Taichi Kaji, Yudai Suzuki, Yoshiki Matsuda, Shu Tanaka, Mayu Muramatsu

Scientific Reports

Journal
Quantum & Combinatorial Optimization Novel real number representations in Ising machines and performance evaluation: Combinatorial random number sum and constant division

Katsuhiro Endo, Yoshiki Matsuda, Shu Tanaka, Mayu Muramatsu

PLoS ONE

Journal
FPGA & Hardware Transparent Broadband VPN Gateway: Achieving 0.39 Tbps per Tunnel with Bump-in-the-Wire

Kenji Tanaka, Takashi Uchida, Yuki Matsuda, Yuki Arikawa, Shinya Kaji, Takeshi Sakamoto

IEEE INFOCOM 2024 (IEEE Conference on Computer Communications)

Conference
2023
HPC & Parallel Computing A New Sparse GEneral Matrix-matrix Multiplication Method for Long Vector Architecture by Hierarchical Row Merging

Hikaru Takayashiki, Hotaka Yagi, Hiroki Nishimoto, Naoki Yoshifuji

SC23 Workshops (SC-W '23)

Conference
Quantum & Combinatorial Optimization Chemical design with GPU-based Ising machines

Zetian Mao, Yoshiki Matsuda, Ryo Tamura, Koji Tsuda

Digital Discovery

Journal
Quantum & Combinatorial Optimization ISAAQ: Ising Machine Assisted Quantum Compiler

Soshun Naito, Yoshihiko Hasegawa, Yoshiki Matsuda, Shu Tanaka

arXiv

Preprint
2022
AI & Machine Learning Establishment of a deep-learning system to diagnose BI-RADS4a or higher using breast ultrasound for clinical application

Tetsu Hayashida, Erina Odani, Masayuki Kikuchi, Aiko Nagayama, Tomoko Seki, Maiko Takahashi, Noriyuki Futatsugi, Akiko Matsumoto, Takeshi Murata, Rurina Watanuki, Takamichi Yokoe, Ayako Nakashoji, Hinako Maeda, Tatsuya Onishi, Sota Asaga, Takashi Hojo, Hiromitsu Jinno, Keiichi Sotome, Akira Matsui, Akihiko Suto, Shigeru Imoto, Yuko Kitagawa

Cancer Science

Journal
FPGA & Hardware CiraaS: cloud computing with programmable logic

Kenji Tanaka, Yuki Arikawa, Tsuyoshi Ito, Yuki Matsuda, Keisuke Kamahori, Shinya Kaji, Takeshi Sakamoto

ACM SIGCOMM 2022 Poster and Demo Sessions (SIGCOMM '22)

Conference
Quantum & Combinatorial Optimization A phase-field model by an Ising machine and its application to the phase-separation structure of a diblock polymer

Katsuhiro Endo, Yoshiki Matsuda, Shu Tanaka, Mayu Muramatsu

Scientific Reports

Journal
HPC & Parallel Computing ARM 4-BIT PQ: SIMD-Based Acceleration for Approximate Nearest Neighbor Search on ARM

Yusuke Matsui, Yoshiki Imaizumi, Naoya Miyamoto, Naoki Yoshifuji

IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP 2022)

Conference
HPC & Parallel Computing VIPP: Validation-Included Precision-Parametric N-Body Benchmark Suite

Shigeyuki Sato, Kota Iizuka, Naoki Yoshifuji, Masaki Natsume

IEEE International Symposium on Performance Analysis of Systems and Software (ISPASS 2022)

Conference
2021
Other Expansion sequencing: Spatially precise in situ transcriptomics in intact biological systems

Shahar Alon, Daniel R. Goodwin, Anubhav Sinha, Asmamaw T. Wassie, Fei Chen, Evan R. Daugharthy, Yosuke Bando, Atsushi Kajita, Andrew G. Xue, Karl Marrett, Robert Prior, Yi Cui, Andrew C. Payne, Chun-Chen Yao, Ho-Jun Suk, Ru Wang, Chih-Chieh (Jay) Yu, Paul Tillberg, Paul Reginato, Nikita Pak, Songlei Liu, Sukanya Punthambaker, Eswar P. R. Iyer, Richie E. Kohman, Jeremy A. Miller, Ed S. Lein, Ana Lako, Nicole Cullen, Scott Rodig, Karla Helvie, Daniel L. Abravanel, Nikhil Wagle, Bruce E. Johnson, Johanna Klughammer, Michal Slyper, Julia Waldman, Judit Jané-Valbuena, Orit Rozenblatt-Rosen, Aviv Regev, IMAXT Consortium, George M. Church, Adam H. Marblestone, Edward S. Boyden

Science

Journal
2019
FPGA & Hardware A software bridged data transfer on a FPGA cluster by using pipelining and InfiniBand verbs

Takaaki Miyajima, Tomoya Hirao, Naoya Miyamoto, Jeongdo Son, Kentaro Sano

10th International Symposium on Highly-Efficient Accelerators and Reconfigurable Technologies (HEART 2019)

Conference
Compilers & Optimization Halide and GENESIS for Generating Domain-Specific Architecture of Guided Image Filtering

Akari Ishikawa, Norishige Fukushima, Akira Maruoka, Takuro Iizuka

ISCAS 2019 (IEEE International Symposium on Circuits and Systems)

Conference
HPC & Parallel Computing ClPy: A NumPy-Compatible Library Accelerated with OpenCL

Tomokazu Higuchi, Naoki Yoshifuji, Tomoya Sakai, Yoriyuki Kitta, Ryousei Takano, Tsutomu Ikegami, Kenjiro Taura

IEEE International Parallel and Distributed Processing Symposium Workshops (IPDPSW 2019)

Conference