252 citations · 2.2k across the 98 of their papers we have counts for
18 papers · 1 filter
Self-Organized Criticality of Domain Walls and Magnetization Curve
Hidetsugu Sakaguchi, Yue Zhao
We propose a kind of Ginzburg--Landau equation with quenched randomness. There is a pinning--depinning transition in the system when the external magnetic force is changed. The tra…
One- and Two-dimensional Solitary Wave States in the Nonlinear Kramers Equation with Movement Direction as a Variable
Hidetsugu Sakaguchi, Kazuya Ishibashi
We study self-propelled particles by direct numerical simulation of the nonlinear Kramers equation for self-propelled particles. In our previous paper, we studied self-propelled pa…
Solitary wave state in the nonlinear Kramers equation for self-propelled particles
Hidetsugu Sakaguchi, Kazuya Ishibashi
We study collective phenomena of self-propagating particles using the nonlinear Kramers equation. A solitary wave state appears from an instability of the spatially uniform ordered…
Slip-Size Distribution and Self-Organized Criticality in Block-Spring Models with Quenched Randomness
Hidetsugu Sakaguchi, Shuntaro Kadowaki
We study slowly pulling block-spring models in random media. Second-order phase transitions exist in a model pulled by a constant force in the case of velocity-strengthening fricti…
Anomalous Fluctuations in Autoregressive Models with Long-Term Memory
Hidetsugu Sakaguchi, Haruo Honjo
An autoregressive model with a power-law type memory kernel is studied as a stochastic process that exhibits a self-affine-fractal-like behavior for a small time scale. We find num…
Reaction-diffusion-advection equation in binary tree networks and optimal size ratio
Hidetsugu Sakaguchi
A simple reaction-diffusion-advection equation is proposed in a dichotomous tree network to discuss an optimal network. An optimal size ratio r is evaluated by the principle of max…
Numerical Simulation of Three-Dimensional Dendrites using Coupled Map Lattices
Hidetsugu Sakaguchi, Mai Gondou, Haruo Honjo
Three dimensional dendrites are studied with a coupled map lattice model. We study the fractal dimensions, the f(α) spectrum, the size distribution of sidebranches, and the envelop…
Melting Transition of Vortex Lattice in Point Vortex Systems
Hidetsugu Sakaguchi, Kenji Kita
Point vortices take a triangular lattice structure in a rotating system as a minimum energy state. We perform a numerical simulation of point vortex systems using initial condition…
Locomotive and reptation motion induced by internal force and friction
Hidetsugu Sakaguchi, Taisuke Ishihara
We propose a simple mechanical model of locomotion induced by internal force and friction. We first construct a system of two elements as an analog of the bipedal motion. The inter…
Self-organized criticality in an interface-growth model with quenched randomness
Hidetsugu Sakaguchi
We study a modified model of the Kardar-Parisi-Zhang equation with quenched disorder, in which the driving force decreases as the interface rises up. A critical state is self-organ…
Cooperative jump motions of jammed particles in a one-dimensional periodic potential
Hidetsugu Sakaguchi
Cooperative jump motions are studied for mutually interacting particles in a one-dimensional periodic potential. The diffusion constant for the cooperative motion in systems includ…
Delocalization transition of a small number of particles in a box with periodic boundary conditions
Hidetsugu Sakaguchi
We perform molecular dynamics simulation of a small number of particles in a box with periodic boundary conditions from a view point of chaotic dynamical systems. There is a transi…
Generalized Einstein Relation for Brownian Motion in Tilted Periodic Potential
Hidetsugu Sakaguchi
A generalized Einstein relation is studied for Brownian motion in a tilted potential. The exact form of the diffusion constant of the Brownian motion is compared with the generaliz…
Efficiency and Fluctuation in Tight-Coupling Model of Molecular Motor
Hidetsugu Sakaguchi
A simple tight-coupling model of a molecular chemical engine is proposed. The efficiency of the chemical engine and its average velocity can be explicitly calculated. The diffusion…
Reaction-Diffusion System in a Vesicle with Semi-Permeable Membrane
Hidetsugu Sakaguchi
We study the Schloegl model in a vesicle with semi-permeable membrane. The diffusion constant takes a smaller value in the membrane region, which prevents the outflow of self-catal…
Dynamic Scaling of an Adsorption-Diffusion Process on Fractals
Hidetsugu Sakaguchi
A dynamic scaling of a diffusion process involving the Langmuir type adsorption is studied. We find dynamic scaling functions in one and two dimensions and compare them with direct…
Renormalization-group and numerical analysis of a noisy Kuramoto-Sivashinsky equation in 1+1 dimensions
K. Ueno, H. Sakaguchi, M. Okamura
The long-wavelength properties of a noisy Kuramoto-Sivashinsky (KS) equation in 1+1 dimensions are investigated by use of the dynamic renormalization group (RG) and direct numerica…
Fluctuation Dissipation Relation for a Langevin Model with Multiplicative Noise
H. Sakaguchi
A random multiplicative process with additive noise is described by a Langevin equation. We show that the fluctuation-dissipation relation is satisfied in the Langevin model, if th…