USAMI Hiroyuki

J-GLOBAL         Last updated: Nov 11, 2019 at 16:07
 
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Name
USAMI Hiroyuki
Affiliation
Gifu University
Section
Faculty of Engineering

Research Interests

 
 

Research Areas

 
 

Academic & Professional Experience

 
 
   
 
Associate Professor, Hiroshima University Faculty of Integrated Arts and Sciences, Faculty of Integrated Arts and Sciences
 

Education

 
 
 - 
1987
Graduate School, Division of Natural Science, Hiroshima University
 
 
 - 
1982
Faculty of Science, Nagoya University
 

Published Papers

 
An inverse blow-up problem
Yutaka KAMIMURA, USAMI Hiroyuki
Proc. Japan Acad., Ser. A   261 6368-6410   2016   [Refereed]
Usami Hiroyuki(Gifu University),Kamo Ken-ichi(Sapporo Medical University)
ロンドン数学会報告集   42(3) 420-428   Jul 2010
Asymptotic behavior of positive solutions of a Lanchester-type model
Tran Thi Huyen Trang, Hiroyuki USAMI
9(2) 241-251   [Refereed]

Misc

 
Toshiaki Kusahara, Hiroyuki Usami
Czechoslovak Mathematical Journal   50 185-196
Tomomitsu Teramoto, Hiroyuki Usami
Pacific Journal of Mathematics   202 247-255   Apr 2016
This paper treats the second order semilinear elliptic systems of the form δu = p(x)να, δν = q(x)uβ, x ∈ RN where α, β > 0 are constants satisfying αβ > 1, and p, q ∈ C(RN; (0, ∞)). We obtain a Liouville type theorem for non-negative entire soluti...
Hiroyuki Usami
Proceedings of the Royal Society of Edinburgh Section A: Mathematics   139 1071-1089   Oct 2009
We show how one-dimensional generalized Riccati-type inequalities can be employed to analyse asymptotic behaviour of solutions of elliptic problems. We give Liouville-type theorems as well as necessary conditions for the existence of solutions of ...
Ken ichi Kamo, Hiroyuki Usami
Nonlinear Analysis, Theory, Methods and Applications   68 1627-1639
In this paper we consider positive solutions of second order quasilinear ordinary differential equations with singular nonlinearities. We obtain asymptotic equivalence theorems for asymptotically superlinear solutions and decaying solutions. By us...
Ken Ichi Kamo, Hiroyuki Usami
Journal of Mathematical Analysis and Applications   271 297-312
We obtain asymptotic forms of positive solutions of third-order Emden-Fowler equations. These results improve earlier results for asymptotic behavior of positive solutions considerably. © 2002 Elsevier Science (USA). All rights reserved.
Hiroyuki Usami
Journal of Mathematical Analysis and Applications   433 1486-1501   Jan 2016
© 2015 Elsevier Inc. We determine asymptotic forms of slowly decaying positive solutions of quasilinear ordinary differential equations related to so-called p-Laplace equation.
Ken Ichi Kamo, Hiroyuki Usami
Electronic Journal of Differential Equations   2007 1-12
Asymptotic forms are determined for positive solutions which are called weakly increasing solutions to quasilinear ordinary differential equations. © 2007 Texas State University.
Ken Ichi Kamo, Hiroyuki Usami
Bulletin of the London Mathematical Society   42 420-428
We consider quasilinear ordinary differential equations with sub-homogeneity near infinity. A necessary and sufficient condition is obtained for the equations to have slowly decaying positive solutions. Asymptotic forms of such positive solutions ...
Yutaka Kamimura, Hiroyuki Usami
Proceedings of the Japan Academy Series A: Mathematical Sciences   90 127-132   Jan 2014
© 2014 The Japan Academy. We study an inverse problem to determine a nonlinearity of an autonomous equation from a blow-up time of solutions of the equation. A local well-posedness of the inverse problem near a nonlinearity of the type u1+σ, σ > 0...
Yuki Naito, Hiroyuki Usami
Mathematische Zeitschrift   225 167-175

Works

 
Oscillation theory for semilinear elliptic partial differential equations
1996
Oscillation theory for quasilinear elliptic partial differential equations
1998
On nonnegative nontrivial solutions of quasilinear elliptic partial differential equations
1996

Research Grants & Projects

 
Ministry of Education, Culture, Sports, Science and Technology: Grants-in-Aid for Scientific Research(基盤研究(C))
Project Year: 2005 - 2008    Investigator(s): Hiroyuki USAMI
Ministry of Education, Culture, Sports, Science and Technology: Grants-in-Aid for Scientific Research(基盤研究(C))
Project Year: 2002 - 2004    Investigator(s): Hiroyuki USAMI
1.We consider second-order quasilinear ordinary differential equations which can be regarded as generalization of the Emden-Fowler equation. We determine asymptotic forms of every positive solutions. We also establish uniqueness of several types o...
Ministry of Education, Culture, Sports, Science and Technology: Grants-in-Aid for Scientific Research(基盤研究(C))
Project Year: 2000 - 2001    Investigator(s): Hiroyuki USAMI
(1) Quasilinear ODEs of seond-order, which are generalizations of Emden's equation, are considered. Asymptotic representations of positive solutions are obtained explicitly. When nonlinear terms have singularities at the origin, uniqueness of deca...
Ministry of Education, Culture, Sports, Science and Technology: Grants-in-Aid for Scientific Research(基盤研究(C))
Project Year: 1998 - 1999    Investigator(s): 柴田 徹太郎, Hiroyuki USAMI
(1) Eigenvalue Problems of Elliptic Equations : Two-parameter eigenvalue problems for semilinear elliptic equations are studied. We establish asymptotic properties of (variational) eigenvalues and eigenfunctions. Two-parameter Ambrosetti-Prodi pro...
Ministry of Education, Culture, Sports, Science and Technology: Grants-in-Aid for Scientific Research(基盤研究(C))
Project Year: 1997 - 1998    Investigator(s): Hiroyuki USAMI
(1) Oscillation criteria for elliptic equations : Effective oscillation criteria are established for second-order quasilinear elliptic equations whose leading terms are degenerate Laplacians. Our method is based on comparison principles and asympt...