• School Mathematics
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• v.2 no.2
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• pp.333-355
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• 2000

In this paper, possibility of practical use of cryptarithmetic problems in teaching and learning of mathematics is discussed. There might be seven cases to use them practically like followings: (1) Cryptarithmetic problems might be used for deepening the mathematical knowledges. (2) Cryptarithmetic problems might be used for fostering mathematical thinking abilities. (3) Cryptarithmetic problems might be used for fostering problem solving abilities. (4) Cryptarithmetic problems might be used as open ended problems. (5) Cryptarithmetic problems might be used as materials for personalized learning. (6) Cryptarithmetic problems might be used as materials for cooperative learning. (7) Cryptarithmetic problems might be used as materials for problems posing.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.2 no.1
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• pp.15-26
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• 1998

By "secure", we mean that some well-defined computational assumption can be shown to be sufficient for the scheme not to be existentially forgeable, even under an adaptive chosen message attack. Most, if not all, signature schemes used in practice are based on a computational assumption that is certainly necessary for this kind of security, not known to be sufficient. Since the work of Goldwasser, Micali and Rivest[?], many researches have been done for the secure signature schemes. We modify the Cramer-Damg$\dot{a}$rd scheme to implement a practical and secure signature scheme for smart cards.

• Journal of Applied and Pure Mathematics
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• v.5 no.5_6
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• pp.303-313
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• 2023

Generalized strictly diagonally dominant matrices have a wide range of applications in matrix theory and practical applications, so it is of great theoretical and practical value to study their numerical determination methods. In this paper, we study the numerical determination of generalized strictly diagonally dominant matrices by using the properties of generalized strictly diagonally dominant matrices. We obtain a new criterion for subdivision iteration determination of the generalized strictly diagonally dominant matrices by subdividing the set of non-prevailing row indices and constructing new iteration factors for the set of predominant row indices, new elements of the positive diagonal factors are derived. Advantages are illustrated by numerical examples.

• School Mathematics
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• v.1 no.1
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• pp.217-234
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• 1999

The first part of this paper examines the assumptions underlying traditional types of standardized testing compared with assumptions underlying innovative types of performance assessment. The second part focuses on directions for the future. The third part gives examples from closed related projects which were designed to find practical ways to implement recommendations.

• Journal of applied mathematics & informatics
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• v.20 no.1_2
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• pp.17-34
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• 2006

Inverse coefficient identification problems associated with the fourth-order Sturm-Liouville operator in the steady state Euler-Bernoulli beam equation are investigated. Unlike previous studies in which spectral data are used as additional information, in this paper only boundary information is used, hence non-destructive tests can be employed in practical applications.

• Journal of applied mathematics & informatics
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• v.28 no.3_4
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• pp.913-921
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• 2010

The derivative influence measure is adapted to the Cholesky decomposition of a covariance matrix. Formulas for the derivative influence of observations on the Cholesky root and the inverse Cholesky root of a sample covariance matrix are derived. It is easy to implement this influence diagnostic method for practical use. A numerical example is given for illustration.

• Journal of the Korean Mathematical Society
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• v.34 no.4
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• pp.927-947
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• 1997

A practical estimation method for groundwater level elevations is introduced. Using geostatistical techniques with drift, averaging process and ratio, experimental variograms show significant improved coorelation compared with those from conventional techniques. The estimation method is applied to a field experimental data set.

• The Mathematical Education
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• v.43 no.4
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• pp.405-417
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• 2004

This study is on the use of mathematics program for School Mathematics Education. According to the ‘technology principle’ by NCTM and teaching-learning methods by the 7th curriculum, we developed mathematics learning activities with mathematics program. This activity is to construct designs with graphs by using mathematics program(GrafEq.). In this study, we practiced these learning activities with pre-service mathematics teachers. The mathematics educational effects of these learning activities in this study are analyzed as follows; active & spontaneous search for mathematical knowledge, the experience of problem solving, affirmative view-point of mathematics, understanding of practical use of mathematics, acquisition an interest & motivation of learning mathematics etc. When students learn graphs of function, the concept of inequality in secondary school mathematics class., mathematics teachers can make a good use of constructing designs by mathematics program(GrafEq.). This will help to practice of teaching-learning methods by the 7th curriculum.

• Journal of applied mathematics & informatics
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• v.10 no.1_2
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• pp.1-15
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• 2002

In this paper an important stability property of the extremes under power normalizations is discussed. It is proved that the restricted convergence of the Power normalized extremes on an arbitrary nondegenerate interval implies the weak convergence. Moreover, this implication, in an important practical situation, is obtained when the sample size is considered as a random variable distributed geometrically with mean n.

• Journal of the Korean Mathematical Society
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• v.51 no.1
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• pp.99-111
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• 2014

In this paper, we deal with the problem of practical observer design and the practical stabilization for a class of perturbed impulsive systems. We show that, under the classical conditions of uniform complete controllability and uniform complete observability of the nominal system without impulsive effects, it is possible to design an observer controller for a class of perturbed linear impulsive system when the origin is not an equilibrium point.