著者
村上 澄男
出版者
一般社団法人 日本応用数理学会
雑誌
応用数理 (ISSN:24321982)
巻号頁・発行日
vol.5, no.4, pp.329-345, 1995-12-15 (Released:2017-04-08)
参考文献数
42
被引用文献数
2

A review of Continuum Damage Mechanics (or simply, damage mechanics) with special emphasis on its applicability to the damage and fracture analysis of stuctural elements is presented. Notion of damage mechanics, mathematical description of material damage, fundamental theories of the constitutive and evolution equations of damaging materials are discussed first. Irreversible themodynamical theory to formulate the constitutive and evolution equations is presested as a systematic framework to establish rational models. Finally, applicability and the related numerical problems of the local approach to fracture based on the damage mechanics and the finite element method are discussed, especially in relation to the problems of creep crack growth analysis. The convergence of the solutions and the procedures to suppress the mesh-dependence of the results are also discussed.
著者
山本 昌宏
出版者
一般社団法人 日本応用数理学会
雑誌
応用数理 (ISSN:24321982)
巻号頁・発行日
vol.10, no.2, pp.85-95, 2000-06-15 (Released:2017-04-08)
参考文献数
26

We discuss the mathematical analysis in non-destructive techniques and stress the role. For the account, we take one problem of determining subboundaries by means of a stationary heat conduction process. A part of boundary is unknown to be determined from measurements of temperature and heat flux on the rest subboundary. In this problem, we distinguish two schemes: (A) Original continuous forward problem=Discretized forward problem=Inverse problem to the discretized forward problem. (B) Original continuous forward problem=Inverse problem to the continuous forward problem=Discretized inverse problem. As for the second step in the scheme (B), we show the uniqueness and stability for our inverse problem and point usefulness of such results for numerical computations. We assert that the mathematical analysis should eventually synthesize these two schemes.
著者
田中 冬彦 山形 浩一
出版者
一般社団法人 日本応用数理学会
雑誌
応用数理 (ISSN:24321982)
巻号頁・発行日
vol.28, no.2, pp.2-10, 2018 (Released:2018-09-30)
参考文献数
38

In modern statistics, various problems in statistical inference are formulated in statistical decision theory. Quantum analogue of the theory was first established by Holevo in 1973. After the emergence of quantum information science in 1990s, many theoretical analyses have been developed in his framework. We introduce quantum minimax theorem and quantum local asymptotic normality as recent fundamental results. We also present an attempt to modify Holevoʼs naive framework for practical application. As shown in an illustrative example, such a modification would allow us to design better experiments in quantum physics.
著者
廣政 良 阿部 正幸 岡本 龍明
出版者
一般社団法人 日本応用数理学会
雑誌
日本応用数理学会論文誌 (ISSN:24240982)
巻号頁・発行日
vol.26, no.4, pp.416-439, 2016 (Released:2016-12-25)
参考文献数
23

概要. RSA 仮定に最良帰着するランダムオラクルモデルで安全な署名方式を提案する.この方式は,同等の安全性を持つ既存の方式よりもランダムオラクルを用いる個数が少ない(最小)という利点がある.次に,どのような攻撃者に対しても,安全性を保ったままそのランダムオラクルを置き換えられるようなハッシュ関数が識別不可能性難読化器を用いて構成できることを示す.また,Coron の方式でも同様の結果を示す.
著者
村上 佑希 山本 良太 西村 憲明 上薗 拓郎 山岸 義和
出版者
一般社団法人 日本応用数理学会
雑誌
日本応用数理学会論文誌 (ISSN:24240982)
巻号頁・発行日
vol.28, no.1, pp.39-53, 2018 (Released:2018-03-25)
参考文献数
12

概要. 一本のねじれのない紙の閉じた輪を折って,正四面体の形にすることができる.そのような折り紙展開図は,既約分数p/qで番号づけされる.また,そのような紙の輪を変形させて切ることにより,正四面体を凸多角形に切り開く展開図が系統的に得られる.
著者
石黒 真木夫
出版者
一般社団法人 日本応用数理学会
雑誌
応用数理 (ISSN:24321982)
巻号頁・発行日
vol.4, no.2, pp.125-138, 1994-06-15 (Released:2017-04-08)
参考文献数
15

It is established through a simulation study that if Kepler would have known AIC he could have used it to "prove" his theory. The reasons why the AIC works were sought and it was found that: 1. The AIC could be an un-biased estimate of the "mean expected log likelihood" of models, under mild conditions. 2. The "Mean expected log likelihood" is a reasonable criterion to compare statistical models. 3. The variance of the AIC is in effect small enough to allow the practical comparison of models. 4. If the bootstrap method is applicable, the variance can be estimated.
著者
名迫 健 村上 恭通
出版者
一般社団法人 日本応用数理学会
雑誌
日本応用数理学会論文誌 (ISSN:24240982)
巻号頁・発行日
vol.16, no.4, pp.591-605, 2006-12-25 (Released:2017-04-08)
参考文献数
11

Merkle and Hellman proposed a knapsack scheme using the superincreasing sequence as a trapdoor. Kasahara and Murakami introduced the trapdoor using even-odd check in shifted values of the secret sequence. These sequences are typical trapdoors of knapsack schemes using the modular multiplication. In this paper, we propose a method of combining these trapdoors. We also propose a high-density knapsack cryptosystem using the proposed trapdoor. Moreover, we discuss on the security of the proposed scheme against Shamir's attack and the low-density attack which are conventional attacks for knapsack schemes.
著者
緒方 秀教
出版者
一般社団法人 日本応用数理学会
雑誌
応用数理 (ISSN:24321982)
巻号頁・発行日
vol.27, no.4, pp.8-15, 2018 (Released:2018-03-31)
参考文献数
9

In this paper, we show an application of hyperfunction theory to numerical integration. It is based on the remark that, in hyperfunction theory, functions with singularities such as poles, discontinuities and delta impulses are expressed in terms of complex holomorphic functions. In our method, we approximate a desired integral by approximating the complex integral which defines the desired integral as an hyperfunction integral by the trapezoidal rule. Theoretical error analysis shows that the approximation by our method converges geometrically, which is due to the fact that the approximation by the trapezoidal rule of the integral of a periodic analytic function over one period interval or the integral of an analytic function over the whole infinite interval converges geometrically. Numerical examples show that our method is efficient especially for integrals with strong end-point singularities.
著者
國廣 昇 太田 和夫
出版者
一般社団法人 日本応用数理学会
雑誌
応用数理 (ISSN:24321982)
巻号頁・発行日
vol.18, no.3, pp.218-225, 2008-09-25 (Released:2017-04-08)
参考文献数
21

2008年3月号に引き続いて,RSA暗号の格子理論に基づくいくつかの攻撃を紹介する.前回は,暗号の解読を1変数の法付きの方程式に帰着させ,この方程式を解くことによる攻撃のみを紹介した.本稿では,2変数以上の方程式に帰着される場合について紹介する.
著者
松尾 宇泰 杉原 正顯 森 正武
出版者
一般社団法人 日本応用数理学会
雑誌
日本応用数理学会論文誌 (ISSN:24240982)
巻号頁・発行日
vol.7, no.3, pp.307-319, 1997-09-15 (Released:2017-04-08)
参考文献数
8

Through numerical experiments we compare the performance of the three algorithms (Linpack algorithm, Hager's algorithm, and Natori Tsukamoto's algorithm) and their variants for estimating the condition number of a matrix, and make recommendation concerning the use of the estimates in applications.
著者
松浦 望
出版者
一般社団法人 日本応用数理学会
雑誌
日本応用数理学会論文誌 (ISSN:24240982)
巻号頁・発行日
vol.23, no.1, pp.55-107, 2013-03-25 (Released:2017-04-08)
参考文献数
89

曲線と曲面の差分幾何について,基本的かつ典型的と思われる例をいくつか挙げながら,その考え方や手法を説明する.とりわけ離散可積分系理論との連関を強調して,具体的な差分方程式と,それによって記述される幾何学的なオブジェクトを構成することに関心を向ける.
著者
山中 卓 中川 秀敏 杉原 正顯
出版者
一般社団法人 日本応用数理学会
雑誌
応用数理 (ISSN:24321982)
巻号頁・発行日
vol.27, no.1, pp.5-12, 2017 (Released:2017-06-30)
参考文献数
18

This article comprehensively reviews some applications of Hawkes process to credit risk modeling with “contagion effect”. Credit risk is the risk associated with financial losses caused by credit events such as debtorsʼ defaults or credit rating transitions. Financial institutions are required to assess more accurately total credit risk of their large credit portfolios for better risk managements. As such, credit risk quantification models are desired to capture the effect of credit risk contagions, which may cause extreme financial losses. Hawkes process is a nonnegative integer-valued stochastic process which has been often used as a basic model for counting contagious events such as infectious diseases in epidemiology and earthquake in seismology. Similarly, modeling with Hawkes process enables us to easily capture some features of contagious credit events and thus to improve the performance of assessing total credit risks. In addition, a multivariate Hawkes process has capability of estimating mutual contagion effects among different industrial sectors. In this article, as for credit risk modeling and analyses with Hawkes processes, not only an introductory theoretical review but some illustrative results from some recent works of the present authors of empirical analyses are presented.