Hiroyuki Usami

475 total citations
45 papers, 377 citations indexed

About

Hiroyuki Usami is a scholar working on Applied Mathematics, Numerical Analysis and Computational Theory and Mathematics. According to data from OpenAlex, Hiroyuki Usami has authored 45 papers receiving a total of 377 indexed citations (citations by other indexed papers that have themselves been cited), including 42 papers in Applied Mathematics, 20 papers in Numerical Analysis and 18 papers in Computational Theory and Mathematics. Recurrent topics in Hiroyuki Usami's work include Nonlinear Differential Equations Analysis (27 papers), Differential Equations and Boundary Problems (21 papers) and Differential Equations and Numerical Methods (19 papers). Hiroyuki Usami is often cited by papers focused on Nonlinear Differential Equations Analysis (27 papers), Differential Equations and Boundary Problems (21 papers) and Differential Equations and Numerical Methods (19 papers). Hiroyuki Usami collaborates with scholars based in Japan and Canada. Hiroyuki Usami's co-authors include Ken‐ichi Kamo, Yūki Naito, Takaŝi Kusano, Manabu Naito, Akio Ogata and Charles A. Swanson and has published in prestigious journals such as Journal of Mathematical Analysis and Applications, Archive for Rational Mechanics and Analysis and Journal of Differential Equations.

In The Last Decade

Hiroyuki Usami

38 papers receiving 320 citations

Peers — A (Enhanced Table)

Peers by citation overlap · career bar shows stage (early→late) cites · hero ref

Name h Career Trend Papers Cites
Hiroyuki Usami Japan 13 339 170 143 56 36 45 377
Jaroslav Jaroš Slovakia 11 318 0.9× 99 0.6× 167 1.2× 93 1.7× 40 1.1× 38 363
M. Matzeu Italy 11 325 1.0× 241 1.4× 76 0.5× 99 1.8× 21 0.6× 43 396
M. N. Nkashama United States 13 331 1.0× 181 1.1× 211 1.5× 85 1.5× 75 2.1× 27 416
Colette De Coster France 9 248 0.7× 179 1.1× 79 0.6× 61 1.1× 33 0.9× 30 290
Marek Galewski Poland 10 333 1.0× 222 1.3× 124 0.9× 52 0.9× 48 1.3× 89 386
C. De Coster Belgium 7 270 0.8× 132 0.8× 151 1.1× 42 0.8× 27 0.8× 14 322
Robert Dalmasso France 8 273 0.8× 179 1.1× 65 0.5× 60 1.1× 21 0.6× 36 301
Juan R. Esteban Spain 5 289 0.9× 231 1.4× 71 0.5× 109 1.9× 50 1.4× 8 354
András Rontó Czechia 12 276 0.8× 88 0.5× 257 1.8× 56 1.0× 39 1.1× 54 356
R. Iannacci Italy 8 257 0.8× 138 0.8× 155 1.1× 74 1.3× 39 1.1× 14 306

Countries citing papers authored by Hiroyuki Usami

Since Specialization
Citations

This map shows the geographic impact of Hiroyuki Usami's research. It shows the number of citations coming from papers published by authors working in each country. You can also color the map by specialization and compare the number of citations received by Hiroyuki Usami with the expected number of citations based on a country's size and research output (numbers larger than one mean the country cites Hiroyuki Usami more than expected).

Fields of papers citing papers by Hiroyuki Usami

Since Specialization
Physical SciencesHealth SciencesLife SciencesSocial Sciences

This network shows the impact of papers produced by Hiroyuki Usami. Nodes represent research fields, and links connect fields that are likely to share authors. Colored nodes show fields that tend to cite the papers produced by Hiroyuki Usami. The network helps show where Hiroyuki Usami may publish in the future.

Co-authorship network of co-authors of Hiroyuki Usami

This figure shows the co-authorship network connecting the top 25 collaborators of Hiroyuki Usami. A scholar is included among the top collaborators of Hiroyuki Usami based on the total number of citations received by their joint publications. Widths of edges represent the number of papers authors have co-authored together. Node borders signify the number of papers an author published with Hiroyuki Usami. Hiroyuki Usami is excluded from the visualization to improve readability, since they are connected to all nodes in the network.

All Works

20 of 20 papers shown
1.
Usami, Hiroyuki, et al.. (2023). Asymptotic forms of solutions of half-linear ordinary differential equations with integrable perturbations. Hiroshima Mathematical Journal. 53(2). 1 indexed citations
2.
Naito, Manabu & Hiroyuki Usami. (2022). On the existence and asymptotic behavior of solutions of half-linear ordinary differential equations. Journal of Differential Equations. 318. 359–383. 4 indexed citations
3.
Usami, Hiroyuki, et al.. (2021). Asymptotic forms of solutions of perturbed half-linear ordinary differential equations. Archivum Mathematicum. 27–39. 2 indexed citations
4.
Usami, Hiroyuki, et al.. (2021). Application of generalised Riccati equations to analysis of asymptotic forms of solutions of perturbed half-linear ordinary differential equations. International Journal of Dynamical Systems and Differential Equations. 11(3/4). 378–378.
5.
Usami, Hiroyuki, et al.. (2017). Asymptotic behavior of positive solutions of a Lanchester-type model. Differential Equations & Applications. 241–252.
6.
7.
Kamo, Ken‐ichi & Hiroyuki Usami. (2010). Characterization of slowly decaying positive solutions of second-order quasilinear ordinary differential equations with sub-homogeneity. Bulletin of the London Mathematical Society. 42(3). 420–428. 7 indexed citations
8.
Kamo, Ken‐ichi & Hiroyuki Usami. (2007). ASYMPTOTIC FORMS OF WEAKLY INCREASING POSITIVE SOLUTIONS FOR QUASILINEAR ORDINARY DIFFERENTIAL EQUATIONS. Electronic Journal of Differential Equations. 2007(126). 1–12. 19 indexed citations
9.
Kamo, Ken‐ichi & Hiroyuki Usami. (2007). Asymptotic forms of positive solutions of quasilinear ordinary differential equations with singular nonlinearities. Nonlinear Analysis. 68(6). 1627–1639.
10.
Usami, Hiroyuki, et al.. (2007). Oscillation theorems of quasilinear elliptic equations with arbitrary nonlinearities. Differential and Integral Equations. 20(5). 1 indexed citations
11.
Naito, Manabu & Hiroyuki Usami. (2006). Existence of nonoscillatory solutions to second-order elliptic systems of Emden-Fowler type. Indiana University Mathematics Journal. 55(1). 317–340. 4 indexed citations
12.
Kamo, Ken‐ichi & Hiroyuki Usami. (2002). Asymptotic forms of positive solutions of third-order Emden–Fowler equations. Journal of Mathematical Analysis and Applications. 271(2). 297–312. 1 indexed citations
13.
Naito, Yūki & Hiroyuki Usami. (1997). Nonexistence Results of Positive Entire Solutions for Quasilinear Elliptic Inequalities. Canadian Mathematical Bulletin. 40(2). 244–253. 20 indexed citations
14.
Naito, Yūki & Hiroyuki Usami. (1997). Entire solutions of the inequality div(A(∣Du∣)Du)≧f(u). Mathematische Zeitschrift. 225(1). 167–175. 33 indexed citations
15.
Usami, Hiroyuki. (1994). Asymptotic behavior of positive solutions of singular Emden-Fowler type equations. Journal of the Mathematical Society of Japan. 46(2). 6 indexed citations
16.
Usami, Hiroyuki. (1994). Nonexistence of Positive Entire Solutions for Elliptic Inequalities of the Mean Curvature Type. Journal of Differential Equations. 111(2). 472–480. 10 indexed citations
17.
Usami, Hiroyuki. (1992). Nonexistence results of entire solutions for superlinear elliptic inequalities. Journal of Mathematical Analysis and Applications. 164(1). 59–82. 16 indexed citations
18.
Usami, Hiroyuki. (1992). Positive solutions of singular Emden-Fowler type systems. Hiroshima Mathematical Journal. 22(2). 4 indexed citations
19.
Usami, Hiroyuki. (1987). Global existence and asymptotic behavior of solutions of second-order nonlinear differential equations. Journal of Mathematical Analysis and Applications. 122(1). 152–171. 8 indexed citations
20.
Usami, Hiroyuki. (1986). On Bounded Positive Entire Solutions of Semilinear Elliptic Equations. Kobe University Repository Kernel (Kobe University). 1 indexed citations

Rankless uses publication and citation data sourced from OpenAlex, an open and comprehensive bibliographic database. While OpenAlex provides broad and valuable coverage of the global research landscape, it—like all bibliographic datasets—has inherent limitations. These include incomplete records, variations in author disambiguation, differences in journal indexing, and delays in data updates. As a result, some metrics and network relationships displayed in Rankless may not fully capture the entirety of a scholar's output or impact.

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