activity
20222026
most citedStatistical-mechanical study of deep Boltzmann machine given weight parameters after training by singular value decomposition

8 citations · 16 across the 19 of their papers we have counts for

collaborators

22 papers

cs.AI2026

LLM-as-an-Improver: Turning Verification into Better Candidates

Akiyoshi Tomihari, Yuma Ichikawa

Verifier-based selection improves LLM performance by generating multiple candidate solutions and using a verifier to select the most promising one. However, existing methods typica…

cs.SE2026

Kozuchi Agent: A Language-Agnostic Open-Weight Agent for Software Repair

Mehdi Bahrami, Kosaku Kimura, Satoshi Munakata +24

Industrial software-engineering teams increasingly need LLM agents that turn bug reports into correct patches, yet benchmark-scale operation adds long horizons, tool-use discipline…

quant-ph2026

One Qubit Can Beat One Bit: Quantum Advantage for Post-Training Quantization

Yuma Ichikawa, Moeto Mishima

One-bit post-training quantization represents each weight using only its sign, requiring all deployment contexts to share the same binary weight matrix even when their activation s…

cs.AI2026

Addressable Recall Compaction for Long Context-Window Control in AI Agents

Thang Dang, Yuma Ichikawa, Sakina Fatima +1

Long-horizon LLM agents accumulate reasoning traces, actions, and tool observations that can eventually exceed a model's fixed context window. Existing compaction methods address t…

cs.AI2026

LOGOS: A Living Logic for AI Agent Teams That Evolve With Humans

Yuma Ichikawa, Yamato Arai, Kosaku Kimura +2

AI agents are evolving from answer engines into persistent teams that use tools, delegate work, learn from experience, and modify the artifacts that shape their future behavior. Th…

cs.AI2026

EVE-Agent: Evidence-Verifiable Self-Evolving Agents

Yamato Arai, Yuma Ichikawa

Self-evolving agents should not train on examples they cannot justify. Data-free self-evolving search agents offer a scalable route to systems that generate their own questions, an…

cond-mat.stat-mech2026

Tensor-Network Population Annealing

Takumi Oshima, Yuma Ichikawa, Koji Hukushima

We propose a hybrid sampling method, tensor-network population annealing (TNPA), which combines tensor-network (TN) initialization with population annealing (PA). We apply this met…

cs.LG2026

OneComp: One-Line Revolution for Generative AI Model Compression

Yuma Ichikawa, Keiji Kimura, Akihiro Yoshida +11

Deploying foundation models is increasingly constrained by memory footprint, latency, and hardware costs. Post-training compression can mitigate these bottlenecks by reducing the p…

cs.GT2026

Thermal Min-Max Games: Unifying Bounded Rationality and Typical-Case Equilibrium

Yuma Ichikawa

Strategic-form min-max game theory examines the existence, multiplicity, selection of equilibria, and the worst-case computational complexity under perfect rationality. However, in…

stat.ML2025

High-Dimensional Learning Dynamics of Quantized Models with Straight-Through Estimator

Yuma Ichikawa, Shuhei Kashiwamura, Ayaka Sakata

Quantized neural network training optimizes a discrete, non-differentiable objective. The straight-through estimator (STE) enables backpropagation through surrogate gradients and i…

cs.LG2025

Quantization Error Propagation: Revisiting Layer-Wise Post-Training Quantization

Yamato Arai, Yuma Ichikawa

Layer-wise PTQ is a promising technique for compressing large language models (LLMs), due to its simplicity and effectiveness without requiring retraining. However, recent progress…

cs.LG2024★ 1 cited

Optimization by Parallel Quasi-Quantum Annealing with Gradient-Based Sampling

Yuma Ichikawa, Yamato Arai

Learning-based methods have gained attention as general-purpose solvers due to their ability to automatically learn problem-specific heuristics, reducing the need for manually craf…

stat.ML2024

Ratio Divergence Learning Using Target Energy in Restricted Boltzmann Machines: Beyond Kullback--Leibler Divergence Learning

Yuichi Ishida, Yuma Ichikawa, Aki Dote +2

We propose ratio divergence (RD) learning for discrete energy-based models, a method that utilizes both training data and a tractable target energy function. We apply RD learning t…

cs.LG2024★ 1 cited

Statistical Mechanics of Min-Max Problems

Yuma Ichikawa, Koji Hukushima

Min-max optimization problems, also known as saddle point problems, have attracted significant attention due to their applications in various fields, such as fair beamforming, gene…

cs.LG2024

Training-Free Time-Series Anomaly Detection: Leveraging Image Foundation Models

Nobuo Namura, Yuma Ichikawa

Recent advancements in time-series anomaly detection have relied on deep learning models to handle the diverse behaviors of time-series data. However, these models often suffer fro…

stat.ML2024

Continuous Parallel Relaxation for Finding Diverse Solutions in Combinatorial Optimization Problems

Yuma Ichikawa, Hiroaki Iwashita

Finding the optimal solution is often the primary goal in combinatorial optimization (CO). However, real-world applications frequently require diverse solutions rather than a singl…

cs.SC2023

Adaptive Flip Graph Algorithm for Matrix Multiplication

Yamato Arai, Yuma Ichikawa, Koji Hukushima

This study proposes the "adaptive flip graph algorithm", which combines adaptive searches with the flip graph algorithm for finding fast and efficient methods for matrix multiplica…

stat.ML2023★ 3 cited

Learning Dynamics in Linear VAE: Posterior Collapse Threshold, Superfluous Latent Space Pitfalls, and Speedup with KL Annealing

Yuma Ichikawa, Koji Hukushima

Variational autoencoders (VAEs) face a notorious problem wherein the variational posterior often aligns closely with the prior, a phenomenon known as posterior collapse, which hind…

stat.ML2023

Controlling Continuous Relaxation for Combinatorial Optimization

Yuma Ichikawa

Unsupervised learning (UL)-based solvers for combinatorial optimization (CO) train a neural network that generates a soft solution by directly optimizing the CO objective using a c…

stat.ML2023★ 3 cited

High-dimensional Asymptotics of VAEs: Threshold of Posterior Collapse and Dataset-Size Dependence of Rate-Distortion Curve

Yuma Ichikawa, Koji Hukushima

In variational autoencoders (VAEs), the variational posterior often collapses to the prior, known as posterior collapse, which leads to poor representation learning quality. An adj…

stat.ML2022

Toward Unlimited Self-Learning MCMC with Parallel Adaptive Annealing

Yuma Ichikawa, Akira Nakagawa, Hiromoto Masayuki +1

Self-learning Monte Carlo (SLMC) methods are recently proposed to accelerate Markov chain Monte Carlo (MCMC) methods using a machine learning model. With latent generative models,…

cond-mat.dis-nn2022★ 8 cited

Statistical-mechanical study of deep Boltzmann machine given weight parameters after training by singular value decomposition

Yuma Ichikawa, Koji Hukushima

Deep learning methods relying on multi-layered networks have been actively studied in a wide range of fields in recent years, and deep Boltzmann machines(DBMs) is one of them. In t…