Ryoichi Shimizu

731 total citations
34 papers, 367 citations indexed

About

Ryoichi Shimizu is a scholar working on Statistics and Probability, Artificial Intelligence and Management Science and Operations Research. According to data from OpenAlex, Ryoichi Shimizu has authored 34 papers receiving a total of 367 indexed citations (citations by other indexed papers that have themselves been cited), including 15 papers in Statistics and Probability, 11 papers in Artificial Intelligence and 9 papers in Management Science and Operations Research. Recurrent topics in Ryoichi Shimizu's work include Statistical Distribution Estimation and Applications (12 papers), Bayesian Methods and Mixture Models (11 papers) and Probability and Risk Models (8 papers). Ryoichi Shimizu is often cited by papers focused on Statistical Distribution Estimation and Applications (12 papers), Bayesian Methods and Mixture Models (11 papers) and Probability and Risk Models (8 papers). Ryoichi Shimizu collaborates with scholars based in Japan, Russia and Germany. Ryoichi Shimizu's co-authors include Yasunori Fujikoshi, Vladimir V. Ulyanov, Masaaki Sibuya, Isao Yoshimura, Laurie Davies, Y. Fujikoshi, J. S. Huang, Yukinobu Hoshino, Katsuari Kamei and Eric W. Cooper and has published in prestigious journals such as The Annals of Statistics, Journal of Multivariate Analysis and Journal of Statistical Planning and Inference.

In The Last Decade

Ryoichi Shimizu

30 papers receiving 300 citations

Peers — A (Enhanced Table)

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

Name h Career Trend Papers Cites
Ryoichi Shimizu Japan 10 237 147 54 52 47 34 367
Takesi Hayakawa Japan 11 262 1.1× 86 0.6× 31 0.6× 51 1.0× 40 0.9× 25 375
R. H. Farrell United States 10 235 1.0× 112 0.8× 41 0.8× 41 0.8× 49 1.0× 21 366
S. W. Dharmadhikari United States 10 117 0.5× 87 0.6× 35 0.6× 34 0.7× 64 1.4× 25 308
Hajime Yamato Japan 9 222 0.9× 192 1.3× 61 1.1× 23 0.4× 36 0.8× 42 329
Michael Nussbaum Germany 10 320 1.4× 125 0.9× 84 1.6× 79 1.5× 40 0.9× 20 482
Ramesh M. Korwar United States 9 265 1.1× 189 1.3× 25 0.5× 33 0.6× 51 1.1× 21 342
Roelof Helmers Netherlands 12 311 1.3× 128 0.9× 87 1.6× 88 1.7× 101 2.1× 45 426
G.P. Steck United States 10 219 0.9× 118 0.8× 41 0.8× 32 0.6× 84 1.8× 26 421
N. G. Ushakov Russia 7 155 0.7× 96 0.7× 50 0.9× 28 0.5× 36 0.8× 39 296
Kumar Jogdeo United States 10 174 0.7× 100 0.7× 81 1.5× 49 0.9× 150 3.2× 18 375

Countries citing papers authored by Ryoichi Shimizu

Since Specialization
Citations

This map shows the geographic impact of Ryoichi Shimizu'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 Ryoichi Shimizu with the expected number of citations based on a country's size and research output (numbers larger than one mean the country cites Ryoichi Shimizu more than expected).

Fields of papers citing papers by Ryoichi Shimizu

Since Specialization
Physical SciencesHealth SciencesLife SciencesSocial Sciences

This network shows the impact of papers produced by Ryoichi Shimizu. 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 Ryoichi Shimizu. The network helps show where Ryoichi Shimizu may publish in the future.

Co-authorship network of co-authors of Ryoichi Shimizu

This figure shows the co-authorship network connecting the top 25 collaborators of Ryoichi Shimizu. A scholar is included among the top collaborators of Ryoichi Shimizu 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 Ryoichi Shimizu. Ryoichi Shimizu 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.
Fujikoshi, Yasunori, Vladimir V. Ulyanov, & Ryoichi Shimizu. (2010). Multivariate Statistics: High-Dimensional and Large-Sample Approximations. CERN Document Server (European Organization for Nuclear Research). 119 indexed citations
2.
Shimizu, Ryoichi, et al.. (2005). An Intelligent Captioning System for the Optimization of Image and Caption Visibility. 한국지능시스템학회 국제학술대회 발표논문집. 108–111. 3 indexed citations
3.
Fujikoshi, Yasunori, Vladimir V. Ulyanov, & Ryoichi Shimizu. (2005). Error bounds for asymptotic expansions of the distribution of multivariate scale mixture. Hiroshima Mathematical Journal. 35(3). 1 indexed citations
4.
Fujikoshi, Y., Vladimir V. Ulyanov, & Ryoichi Shimizu. (2004). L1-norm error bounds for asymptotic expansions of multivariate scale mixtures and their applications to Hotelling's generalized T02. Journal of Multivariate Analysis. 96(1). 1–19. 8 indexed citations
5.
Shimizu, Ryoichi & Yasunori Fujikoshi. (1997). Sharp Error Bounds for Asymptotic Expansions of the Distribution Functions for Scale Mixtures. Annals of the Institute of Statistical Mathematics. 49(2). 285–297. 8 indexed citations
6.
Shimizu, Ryoichi. (1995). Expansion of the Scale Mixture of the Multivariate Normal Distribution with Error Bound Evaluated in the L1-Norm. Journal of Multivariate Analysis. 53(1). 126–138. 5 indexed citations
7.
Fujikoshi, Yasunori & Ryoichi Shimizu. (1989). Error bounds for asymptotic expansions of scale mixtures of univariate and multivariate distributions. Journal of Multivariate Analysis. 30(2). 279–291. 9 indexed citations
8.
Fujikoshi, Yasunori & Ryoichi Shimizu. (1989). Asymptotic Expansions of Some Mixtures of the Multivariate Normal Distribution and Their Error Bounds. The Annals of Statistics. 17(3). 8 indexed citations
9.
Shimizu, Ryoichi, et al.. (1981). General characterization theorems for the Weibull and the stable distributions. Munich Personal RePEc Archive (Ludwig Maximilian University of Munich). 64(8). 241–2. 4 indexed citations
10.
Shimizu, Ryoichi, et al.. (1981). Classification of the Generalized Hypergeometric family of distributions. 34(1). 1–38. 3 indexed citations
11.
Sibuya, Masaaki & Ryoichi Shimizu. (1981). The generalized hypergeometric family of distributions. Annals of the Institute of Statistical Mathematics. 33(2). 177–190. 11 indexed citations
12.
Shimizu, Ryoichi. (1979). A characterization of the exponential distribution. Annals of the Institute of Statistical Mathematics. 31(3). 367–372. 4 indexed citations
13.
Shimizu, Ryoichi. (1974). On the remained term for the central limit theorem. Annals of the Institute of Statistical Mathematics. 26(1). 195–201. 6 indexed citations
14.
Shimizu, Ryoichi. (1972). On the decomposition of stable characteristic functions. Annals of the Institute of Statistical Mathematics. 24(1). 347–353. 3 indexed citations
15.
Shimizu, Ryoichi. (1970). On the domain of partial attraction of semi-stable distributions. Annals of the Institute of Statistical Mathematics. 22(1). 245–255. 20 indexed citations
16.
Shimizu, Ryoichi. (1968). Characteristic functions satisfying a functional equation (I). Annals of the Institute of Statistical Mathematics. 20(1). 187–209. 12 indexed citations
17.
Shimizu, Ryoichi. (1966). Remarks on sufficient statistics. Annals of the Institute of Statistical Mathematics. 18(1). 49–55. 4 indexed citations
18.
Shimizu, Ryoichi. (1965). Certain class of infinitely divisible characteristic functions. Annals of the Institute of Statistical Mathematics. 17(1). 115–132. 4 indexed citations
19.
Sibuya, Masaaki, Isao Yoshimura, & Ryoichi Shimizu. (1964). Negative multinomial distribution. Annals of the Institute of Statistical Mathematics. 16(1). 409–426. 55 indexed citations
20.
Shimizu, Ryoichi. (1962). Characterization of the normal distribution II. Annals of the Institute of Statistical Mathematics. 14(1). 173–178. 3 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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