Tatsuaki Wada
Ibaraki University
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Publication
Featured researches published by Tatsuaki Wada.
Journal of Physics A | 2010
Atsumi Ohara; Tatsuaki Wada
This paper presents new geometric aspects of the behaviors of solutions to the porous medium equation (PME) and its associated equation. First we discuss thermostatistical structure with information geometry on a manifold of generalized exponential densities. A dualistic relation between the two existing formalisms is elucidated. Next by equipping the manifold of q-Gaussian densities with such a structure, we derive several physically and geometrically interesting properties of the solutions. The manifold is proved invariant and attracting for the evolving solutions, which play crucial roles in our analysis. We demonstrate that the moment-conserving projection of a solution coincides with a geodesic curve on the manifold. Further, the evolutional velocities of the second moments and the convergence rate to the manifold are evaluated in terms of the Bregman divergence. Finally we show that the self-similar solution is geometrically special in the sense that it is simultaneously geodesic with respect to the mutually dual two affine connections.
Japanese Journal of Applied Physics | 1990
Tatsuaki Wada; Toshiyuki Nitta; Takashi Nomura; Masahiro Miyao; Minoru Hagino
The influence of CO, CO2 and H2O gases on the stability of negative-electron-affinity (NEA) GaAs photocathodes during operation is investigated in the present work. We have found that exposure both to H2O and CO2 decreases the photocurrent of the photocathode. However, exposure to CO, which is known as a harmful gas to various photocathodes, has little effect on the photocathode stability. Furthermore, the effects of these gases on the restoration of the photocurrent by additional cesium deposition are investigated. These results are discussed with regard to the Cs/O activation layer which plays an important role in NEA GaAs photocathodes.
Physics Letters A | 2007
Tatsuaki Wada; Hiroki Suyari
Abstract Based on the one-parameter generalization of Shannon–Khinchin (SK) axioms presented by one of the authors, and utilizing a tree-graphical representation, we have developed for the first time a two-parameter generalization of the SK axioms in accordance with the two-parameter entropy introduced by Sharma, Taneja, and Mittal. The corresponding unique theorem is also proved. It is found that our two-parameter generalization of Shannon additivity is a natural consequence from the Leibniz product rule of the two-parameter Chakrabarti–Jagannathan difference operator.
European Physical Journal B | 2009
Tatsuaki Wada; Antonio Maria Scarfone
AbstractThe asymptotic behavior of a nonlinear diffusive equation obtained in the framework of the κ-generalized statistical mechanics is studied. The analysis based on the classical Lie symmetry shows that the κ-Gaussian function is not a scale invariant solution of the generalized diffusive equation. Notwithstanding, several numerical simulations, with different initial conditions, show that the solutions asymptotically approach to the κ-Gaussian function. Simple argument based on a time-dependent transformation performed on the related κ-generalized Fokker-Planck equation, supports this conclusion.
Progress of Theoretical Physics Supplement | 2006
Antonio Maria Scarfone; Tatsuaki Wada
Starting from the
Applied Surface Science | 1996
Masayoshi Masui; Masamitsu Sasahara; Tatsuaki Wada; Manabu Takeuchi
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Scientific Reports | 2015
Yutaka Shikano; Tatsuaki Wada; Junsei Horikawa
-distribution function, obtained by applying the maximal entropy principle to the
European Physical Journal B | 2005
Tatsuaki Wada; Antonio Maria Scarfone
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Physica A-statistical Mechanics and Its Applications | 2008
Hiroki Suyari; Tatsuaki Wada
-entropy [G. Kaniadakis, Phys. Rev. E 66 (2002), 056125], we derive the expression of the canonical
Continuum Mechanics and Thermodynamics | 2004
Tatsuaki Wada
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