28 citations · 163 across the 19 of their papers we have counts for
19 papers
Negative Strain-Rate Sensitivity in Metallic Glasses Driven by Rejuvenation-Relaxation Competition: Kinetic Monte Carlo Simulations and a Minimal Effective Model
Tomoaki Niiyama, Akio Ishii, Takahiro Hatano +2
When strain-rate sensitivity (SRS) is negative in metallic glasses, the material becomes weaker as the deformation rate increases, leading to accelerated plastic deformation and, e…
A thin and soft optical tactile sensor for highly sensitive object perception
Yanchen Shen, Kohei Tsuji, Haruto Koizumi +7
Tactile sensing is crucial in robotics and wearable devices for safe perception and interaction with the environment. Optical tactile sensors have emerged as promising solutions, a…
100 Mfps ghost imaging with wavelength division multiplexing
Shin Motooka, Noriki Komori, Tomoaki Niiyama +1
Ghost imaging (GI) and single-pixel imaging (SPI) techniques enable image reconstruction without spatially resolved detectors, offering unique access to wide spectral ranges and ch…
Expanding detection bandwidth via a photonic reservoir for ultrafast optical sensing
Yuito Ito, Tomoaki Niiyama, Tetsuya Asai +3
The detection of ultrafast optical and radio-frequency (RF) signals is crucial for applications ranging from high-speed communications to advanced sensing. However, conventional de…
Blending Optimal Control and Biologically Plausible Learning for Noise-Robust Physical Neural Networks
Satoshi Sunada, Tomoaki Niiyama, Kazutaka Kanno +4
The rapidly increasing computational demands for artificial intelligence (AI) have spurred the exploration of computing principles beyond conventional digital computers. Physical n…
Optical hyperdimensional soft sensing: Speckle-based touch interface and tactile sensor
Kei Kitagawa, Kohei Tsuji, Koyo Sagehashi +2
Hyperdimensional computing (HDC) is an emerging computing paradigm that exploits the distributed representation of input data in a hyperdimensional space, the dimensions of which a…
Ultrafast single-channel machine vision based on neuro-inspired photonic computing
Tomoya Yamaguchi, Kohei Arai, Tomoaki Niiyama +2
High-speed machine vision is increasing its importance in both scientific and technological applications. Neuro-inspired photonic computing is a promising approach to speed-up mach…
Analysis of temporal structure of laser chaos by Allan variance
Naoki Asuke, Nicolas Chauvet, André Röhm +6
Allan variance has been widely utilized in evaluating the stability of the time series generated by atomic clocks and lasers, in time regimes ranging from short to extremely long.…
Gigahertz-rate random speckle projection for high-speed single-pixel image classification
Jinsei Hanawa, Tomoaki Niiyama, Yutaka Endo +1
Imaging techniques based on single-pixel detection, such as ghost imaging, can reconstruct or recognize a target scene from multiple measurements using a sequence of random mask pa…
Optical skin: Sensor-integration-free multimodal flexible sensing
Sho Shimadera, Kei Kitagawa, Koyo Sagehashi +2
The biological skin enables animals to sense various stimuli. Extensive efforts have been made recently to develop smart skin-like sensors to extend the capabilities of biological…
Power-law fluctuations near critical point in semiconductor lasers with delayed feedback
Tomoaki Niiyama, Satoshi Sunada
Since the analogy between laser oscillation and second-order phase transition was indicated in the 1970s, dynamical fluctuations on lasing threshold inherent in critical phenomena…
Physical deep learning based on optimal control of dynamical systems
Genki Furuhata, Tomoaki Niiyama, Satoshi Sunada
Deep learning is the backbone of artificial intelligence technologies, and it can be regarded as a kind of multilayer feedforward neural network. An essence of deep learning is inf…
Mean first passage times reconstruct the slowest relaxations in potential energy landscapes of nanoclusters
Teruaki Okushima, Tomoaki Niiyama, Kensuke S. Ikeda +1
Relaxation modes are the collective modes in which all probability deviations from equilibrium states decay with the same relaxation rates. In contrast, a first passage time is the…
Lotka-Volterra competition mechanism embedded in a decision-making method
Tomoaki Niiyama, Genki Furuhata, Atsushi Uchida +2
Decision making is a fundamental capability of living organisms, and has recently been gaining increasing importance in many engineering applications. Here, we consider a simple de…
Changes of graph structure of transition probability matrices indicate the slowest kinetic relaxations
Teruaki Okushima, Tomoaki Niiyama, Kensuke S. Ikeda +1
Graphs of the most probable transitions for a transition probability matrix, , i.e., the time evolution matrix of the transition rate matrix over a finite time interval…
Structural relaxation affecting shear transformation avalanches in metallic glasses
Tomoaki Niiyama, Masato Wakeda, Tomotsugu Shimokawa +1
Avalanche behaviors, characterized by power-law statistics and structural relaxation that induces shear localization in amorphous plasticity, play an essential role in deciding the…
Slowest kinetic modes revealed by metabasin renormalization
Teruaki Okushima, Tomoaki Niiyama, Kensuke S. Ikeda +1
Understanding the slowest relaxations of complex systems, such as relaxation of glass-forming materials, diffusion in nanoclusters, and folding of biomolecules, is important for ph…
Barrier effect of grain boundaries on the avalanche propagation of polycrystalline plasticity
Tomoaki Niiyama, Tomotsugu Shimokawa
To investigate the barrier effect of grain boundaries on the propagation of avalanche-like plasticity at the atomic-scale, we perform three-dimensional molecular dynamics simulatio…
On the origin of atomistic mechanism of rapid diffusion in alkali halide nanoclusters
Tomoaki Niiyama, Shin-ichi Sawada, Kensuke S. Ikeda +1
To elucidate the atomistic diffusion mechanism responsible for the rapid diffusion in alkali halide nano particles, called Spontaneous Mixing, we execute molecular dynamics simulat…