T. Shigehara

Publication List Details

Period

1995 - 2007

Number

16

Co-Authors

Estimation of Background from Image Sequence with Moving Objects (2007)

T. Kurita, Kurita Shimai, S. Umeyama, T. Shigehara

This paper proposes an adaptive background estimation method from sequence of images in which some moving objects are included. The background value of each pixel is estimated by adaptive robust...

Continuous Spectra of Generalized Kronig-Penney Model (1999)

Cheon, Taksu, Shigehara, T.

The standard Kronig-Penney model with periodic $\delta$ potentials is extended to the cases with generalized contact interactions. The eigen equation which determines the dispersion relation for...

Generalized One-Dimensional Point Interaction in Relativistic and Non-relativistic Quantum Mechanics (1999)

Shigehara, T., Mizoguchi, H., Mishima, T., Cheon, Taksu

We first give the solution for the local approximation of a four parameter family of generalized one-dimensional point interactions within the framework of non-relativistic model with three...

Realization of a Four Parameter Family of Generalized One-Dimensional Contact Interactions by Three Nearby Delta Potentials with Renormalized Strengths (1998)

Shigehara, T., Mizoguchi, H., Mishima, T., Cheon, Taksu

We propose a new method to construct a four parameter family of quantum-mechanical point interactions in one dimension, which is known as all possible self-adjoint extensions of the symmetric...

Equivalence of Local and Separable Realizations of the Discontinuity-Inducing Contact Interaction and Its Perturbative Renormalizability (1998)

Cheon, Taksu, Shigehara, T., Takayanagi, K.

We prove that the separable and local approximations of the discontinuity-inducing zero-range interaction in one-dimensional quantum mechanics are equivalent. We further show that the interaction...

Some Aspects of Generalized Contact Interaction in One-Dimensional Quantum Mechanics (1998)

Cheon, Taksu, Shigehara, T.

We construct a one-dimensional contact interaction ($\epsilon$ potential) which induces the discontinuity of the wave function while keeping its derivative continuous. By combining the $\epsilon$...

Influence of Small Impurities on Low-Energy Electron Dynamics in Two-Dimensional Microscopic Bounded Region (1998)

Shigehara, T., Yokoyama, M., Mizoguchi, H., Mishima, T., Cheon, Taksu

In order to give some insight into a role of small impurities on the electron motion in microscopic devices, we examine from a general viewpoint, the effect of small obstacles on a particle motion at...

Fermion-Boson Duality of One-dimensional Quantum Particles with Generalized Contact Interaction (1998)

Cheon, Taksu, Shigehara, T.

For a system of spinless one-dimensional fermions, the non-vanishing short-range limit of two-body interaction is shown to induce the wave-function discontinuity. We prove the equivalence of this...

Spectral Properties of the Two-Dimensional Laplacian with a Finite Number of Point Interactions (1997)

Shigehara, T., Mizoguchi, H., Mishima, T., Cheon, Taksu

We discuss spectral properties of the Laplacian with multiple ($N$) point interactions in two-dimensional bounded regions. A mathematically sound formulation for the problem is given within the...

Wave Chaos in Quantum Pseudointegrable Billiards (1997)

Shigehara, T., Mizoguchi, H., Mishima, T., Cheon, Taksu

We clarify from a general perspective, the condition for the appearance of chaotic energy spectrum in quantum pseudointegrable billiards with a point scatterer inside.

Realizing Discontinuous Wave Functions with Renormalized Short-Range Potentials (1997)

Cheon, Taksu, Shigehara, T.

It is shown that a potential consisting of three Dirac's delta functions on the line with disappearing distances can give rise to the discontinuity in wave functions with the proper renormalization...

Spectral Properties of Three-Dimensional Quantum Billiards with a Pointlike Scatterer (1997)

Shigehara, T., Cheon, Taksu

We examine the spectral properties of three-dimensional quantum billiards with a single pointlike scatterer inside. It is found that the spectrum shows chaotic (random-matrix-like) characteristics...

Resonance Tunneling in Double-Well Billiards with a Pointlike Scatterer (1996)

Cheon, Taksu, Shigehara, T.

The coherent tunneling phenomenon is investigated in rectangular billiards divided into two domains by a classically unclimbable potential barrier. We show that by placing a pointlike scatterer...

Flux String in Quantum Billiards with Two Particles (1996)

Cheon, Taksu, Shigehara, T.

We examine the quantum motion of two particles interacting through a contact force which are confined in a rectangular domain in two and three dimensions. When there is a difference in the mass scale...

Wave Chaos in Quantum Billiards with Small but Finite-Size Scatterer (1996)

Shigehara, T., Cheon, Taksu

We study the low energy quantum spectra of two-dimensional rectangular billiards with a small but finite-size scatterer inside. We start by examining the spectral properties of billiards with a...

Level spacing distribution of pseudointegrable billiard (1995)

Shigehara, T., Yoshinaga, N., Cheon, Taksu, Mizusaki, T.

In this paper, we examine the level spacing distribution $P(S)$ of the rectangular billiard with a single point-like scatterer, which is known as pseudointegrable. It is shown that the observed...