著者
斉藤 一哉
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.26, no.1, pp.9-14, 2016 (Released:2016-07-27)
参考文献数
18

This study presents a new method for designing self-deploying origami using the geometrically misaligned creases. In this method, some facets are replaced by “holes” such that the systems become a 1-DOF mechanism. These perforated origami models can be folded and unfolded similar to rigidfoldable(without misalignment) models because of their DOF despite the existence of the misalignment. Focusing on the removed facets, the holes will deform according to the motion of the frame of the remaining parts. In the proposed method, these holes are filled with elastic parts and store elastic energy for self-deployment. First, a new extended rigid-folding simulation technique is proposed to estimate the deformation of the holes. Next by using the above technique, the proposed method is applied on arbitrary-size quadrilateral mesh origami. Finally, by using the finite-element method, the authors conduct numerical simulations and confirm the deployment capabilities of the models.
著者
稲葉 寿
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.12, no.3, pp.294-307, 2002-09-25 (Released:2017-04-08)
参考文献数
37

In this paper, we introduce recent developments in mathematical models for demography and epidemics. During last two decades, functional analytic approach for structured population dynamics has been rapidly developed, which was a result of fruitful interaction between applied mathematics and theoretical biology. First, we sketch some developments of idea of asynchronous exponential growth for age-structured populations, which is a modern refinement of traditional idea of Malthusian growth. Next general approach to non-linear structured population models is reviewed with special attention to pair formation models. Finally we consider a Kermack's and McKendrick's epidemic model and an age-structured SIR epidemic model to clear the crucial role of the basic reproduction number in the threshold phenomena. Though we know that many deterministic structured population models have been successfully examined as infinite dimensional dynamical system, even after efforts of two decades, building a universal framework to describe time evolution of structured populations under complex environments has been still an open problem.
著者
江口 真透
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.30, no.3, pp.40-42, 2020-09-24 (Released:2020-12-26)
参考文献数
10
著者
松田 孟留
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.31, no.4, pp.7-14, 2021-12-22 (Released:2022-03-31)
参考文献数
32

In this paper, we review the theory of shrinkage estimation and superharmonicity. First, we introduce Steinʼs paradox on estimation of the normal mean vector and explain its relationship with superharmonicity. Next, we investigate the extension to matrices, in which the shrinkage of singular values plays a key role for exploiting low-rankness. Finally, we illustrate recent developments on shrinkage predictive densities, empirical Bayes marix completion and matrix superharmonicity.
著者
二宮 祥一
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.30, no.4, pp.8-15, 2020-12-22 (Released:2021-03-31)
参考文献数
25

Numerical calculation of E[f(X(1,x))] where {X(t,x)}t≧0 is a diffusion process defined by a stochastic differential equation (SDE) is called weak approximation of the SDE. The author discusses higherorder discretization algorithms based on Kusuokaʼs theory. The fundamental theorem by Kusuoka and three algorithms are explained.
著者
岩本 真裕子
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.26, no.2, pp.14-21, 2016-06-24 (Released:2016-09-30)
参考文献数
16

This study aim to investigate the mechanism of adhesive locomotion in gastropod. It has been reported by previous study that the significant factors of locomotion mechanism are “propagation of muscular waves” and “interfacial friction against the ground”. Interfacial friction has been considered to be controlled by lifting the pedal up, or dynamic viscoelasticity of mucus. To lift pedal up in appropriate timing, complex signals from the center would be necessary although the mechanism of lifting is simple in kinetics. This study focused on the hypothesis of dynamic viscoelasticity of mucus reported by Denny from the point of view of automatic frictional control similar to the mechanism of locomotion in earthworm. Based on the matter of previous study, a simple mathematical model which captures essential factors obtained by qualitative observations is proposed, and the physical parameters in the model are estimated by quantitative results from careful experiments. It has been verified by numerical calculations with the model that the mutual interaction between flexible muscular contraction waves and nonlinear dynamic viscoelasticity of the mucus can achieve an efficient locomotion. The important result in this study is that two locomotion styles, direct wave and retrograde wave, which has been understood by different mechanism, can be realized by the same mechanism.
著者
渡辺 澄夫
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.31, no.3, pp.7-14, 2021-09-22 (Released:2021-12-26)
参考文献数
15

Many statistical models and learning machines are not regular but singular, hence the conventional theory using asymptotic normality can not be employed in analysis of such models. This paper explains the new mathematical theory which enables us to clarify the asymptotic behaviors of the generalization loss and the free energy based on algebraic geometry. Also the short history how this theory has been applied to real world problems is introduced.
著者
三中 信宏
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.32, no.2, pp.80-86, 2022-06-24 (Released:2022-09-30)
参考文献数
34

In the field of statistical data analysis in research, there is considerable discussion about the details of statistical methods and statistical modeling applied to the actual data. However, the fact that philosophical and conceptual issues in statistical science lie behind a variety of practical problems is not often discussed in the open. Meanwhile, this paper discusses the relative comparison of competing hypotheses, model selection by AIC (Akaike’s Information Criterion), and the nature of statistics as “abduction” as nondeductive reasoning, which is based on the statistical criterion of “simplicity.”
著者
清 智也
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.29, no.1, pp.20-26, 2019-03-26 (Released:2019-06-30)
参考文献数
21

Ranking systems are often based on a weighted sum of several quantitative variables. We discuss how to determine the weight. Anatural weighting method is standardization. Other possibilities are principal component analysis and factor analysis. The author recently proposed an objective general index as a different way of weighting. In this paper, we study a relationship between the objective general index and the existing methods.
著者
松谷 茂樹
出版者
一般社団法人 日本応用数理学会
雑誌
応用数理
巻号頁・発行日
vol.13, no.1, pp.48-60, 2003
被引用文献数
1

In 1691, James Bernoulli proposed the following problem called elastica problem : "What shape of elastica, an ideal thin elastic rod in a plane, is allowed ?" Euler essentially solved the problem in 1744 by developing studies of variation problem and elliptic function theory. Their studies are regarded as prototypes of harmonic map theory, nonlinear differential theory, soliton theory, differential geometry, algebraic geometry, theory of moduil of elliptic curves and so on. In this article we mention their mathematical meaning with their historical background from viewpoint of pure and applied mathematics : Their studies started from concreteness to abstractand they applied constructed abstract theory to the concrete problem. We also introduce a current study of statistical mechanics of elasticas, which might be settled by knowledge of hyperelliptic function theory.
著者
松浦 望
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.26, no.3, pp.17-24, 2016 (Released:2016-12-26)
参考文献数
19

This is an overview of the paper[19], which makes a survey of discrete differential geometry of curves and surfaces. We review a few representatives of discrete curves and surfaces, with emphasis on close connections between both the theories of discrete differential geometry and discrete integrable systems.
著者
田中 博
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.96-109, 2000-06-15 (Released:2017-04-08)
参考文献数
10

Basic characteristics, solution algorithm and current trends in the inverse problems in medicine are generally reviewed. First we deal the basic classification of medical inverse problems in relation to the difference of observation: remote sensing and remote probing typed inverse problems. Second, we describe the several characteristics of the solving method which are used in the medical inverse problems. In doing so, we pay close attention to the structure of observational equation and the method to introduce the a priori information to the inverse solution. Among these, Wiener filter method, Tikhonov regularization method are introduced as they are applied in the medical inverse problems. In the above description, several examples such as computed tomograpy, inverse magnetic encephalography and inverse ECG problems are introduced.
著者
松本 耕二
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.29, no.3, pp.39-43, 2019-09-25 (Released:2019-12-26)
参考文献数
6
著者
松谷 茂樹
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.13, no.1, pp.48-60, 2003-03-25 (Released:2017-04-08)

In 1691, James Bernoulli proposed the following problem called elastica problem : "What shape of elastica, an ideal thin elastic rod in a plane, is allowed ?" Euler essentially solved the problem in 1744 by developing studies of variation problem and elliptic function theory. Their studies are regarded as prototypes of harmonic map theory, nonlinear differential theory, soliton theory, differential geometry, algebraic geometry, theory of moduil of elliptic curves and so on. In this article we mention their mathematical meaning with their historical background from viewpoint of pure and applied mathematics : Their studies started from concreteness to abstractand they applied constructed abstract theory to the concrete problem. We also introduce a current study of statistical mechanics of elasticas, which might be settled by knowledge of hyperelliptic function theory.
著者
菊池 誠
出版者
一般社団法人日本応用数理学会
雑誌
応用数理 (ISSN:09172270)
巻号頁・発行日
vol.12, no.2, pp.104-108, 2002-06-15
被引用文献数
6

As an introduction to the special topics section of traffic flow problem, a brief history of mathematical researches in this area is described. Some basic concepts, such as a q-k diagram, are introduced at the same time.
著者
大林 一平
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.26, no.4, pp.7-14, 2017 (Released:2017-03-25)
参考文献数
11

Persistence homology is an important tool for topological data analysis(TDA), and a persistence diagram is a visualization tool of persistent homology. We can compute the geometric features of the data quantitatively using persistence diagrams. When using persistence diagrams, we often want to know which part of the input data is related to the geometric features shown in the persistence diagram. In this paper, we show some approaches to the problem.