Takayuki Kubo

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Although a mucoepidermoid carcinoma is sometimes seen as a neoplasm originating from the salivary glands, its origination from the liver is rare. A review of the medical literature in the English language disclosed only 16 cases originating from the hepatic system. The case explored here is that of an 81-year-old female, without any significant medical(More)
Three-dimensional analysis of the aurora which is an atmospheric phenomenon is significant because the shape of aurora reflects the electromagnetic relationship between the Earth and the Sun, which can influence electric equipments such as satellites. To analyze a number of auroras, our research group set two fish-eye cameras in Poker Flat Research Range(More)
We explore a mechanism of radiative B−L symmetry breaking in analogous to the radiative electroweak symmetry breaking. The breaking scale of B − L symmetry is related to the neutrino masses through the see-saw mechanism. Once we incorporate the U(1)B−L gauge symmetry in SUSY models, the U(1)B−L gaugino, Z̃B−L appears, and it can mediate the SUSY breaking(More)
Anomaly mediated supersymmetry breaking implemented in the minimal supersymmetric standard model (MSSM) is known to suffer from the tachyonic slepton problem leading to breakdown of electric charge conservation. We show however that when MSSM is extended to explain small neutrino masses by gauging the B-L symmetry, the slepton masses can be positive due to(More)
In this paper, we will find the numerical solution of partial differential equations by using the finite element method with Riesz bases that are elevated from ortho normal bases. Especially for the two-dimensional cases, we also propose another way to solve a matrix-valued equation (Lyapunov equation). Moreover, we give the precise inverse formula for(More)
It is demonstrated that the light Higgs boson scenario, which the lightest Higgs mass is less than the LEP bound, mh > 114.4GeV, is consistent with the SUSY seesaw model. With the assumptions of the universal right-handed neutrino mass and the hierarchical mass spectrum of the ordinary neutrinos, the bounds for the right-handed neutrino mass is investigated(More)
In this article, a numerical method is presented for computer assisted proofs to the existence and uniqueness of solutions to Dirichlet boundary value problems in a certain class of nonlinear elliptic equations. In a weak formulation of the problem, a weak solution is described as a zero point of a certain nonlinear map. Based on Newton-Kantorovich theorem,(More)
Inducing magnetism into topological insulators is intriguing for utilizing exotic phenomena such as the quantum anomalous Hall effect (QAHE) for technological applications. While most studies have focused on doping magnetic impurities to open a gap at the surface-state Dirac point, many undesirable effects have been reported to appear in some cases that(More)
This paper presents a method of numerical verification for existence of a global-in-time solution to a class of semilinear parabolic equations. Such a method is based on two main theorems in this paper. One theorem gives a sufficient condition for proving existence of a solution to the semilinear parabolic equations with the initial point t = t′ ≥ 0. If the(More)