• Korean Journal of Mathematics
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• 제22권3호
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• pp.567-581
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• 2014

Over the years, there has been much research conducted on quadratic curves and the set of points with the generalized notion of eccentricity in a plane with metrics such as taxicab distance or Chinese-checker distance. On the other hand, polar taxicab distance has been newly proposed on the polar coordinate system, a type of curvilinear coordinate system, to overcome the limitation of pre-existing metrics in terms of describing curved routes. Previous study has looked into the fundamental properties of this metric. From this point of view, we study the quadratic curves and the set of points with the generalized notion of eccentricity in a plane with polar taxicab distance.

• Journal of applied mathematics & informatics
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• 제24권1_2호
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• pp.283-293
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• 2007

This paper considers single machine scheduling problems with group technology (GT) and deteriorating jobs. A sequence independent setup is required to process a job from a different group and jobs in each group are processed together. We consider the case of jobs whose processing times are a decreasing function of their starting time. The objectives of scheduling problems are to minimize the makespan and the total completion time, respectively. We also provide polynomial time algorithms to solve these problems.

• 한국수학사학회지
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• 제30권3호
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• pp.137-162
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• 2017

The Chinese algebraic method, the tian yuan shu, was developed during Song period (960-1279), of which Li Ye's works contain the earliest testimony. Two 18th century editors commentated on his works: the editor of the Siku quanshu and Li Rui, the latter responding to the former. Korean scholar Nam Byeong-gil added another response in 1855. Differences can be found in the way these commentators considered mathematical objects and procedures. The conflicting nature of these commentaries shows that the same object, the quadratic equation, can beget different interpretations, either a procedure or an assertion of equality. Textual elements in this paper help modern readers reconstruct different authors' understandings and reconsider the evolution of the definition of the object we now call 'equation'.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제6권2호
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• pp.117-122
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• 2002

From the beginning of the 20th century, calculus is gradually offered to high school students in many countries. However, in Chinese high school, the instruction on calculus is nearly an untouched field. Many people don't believe that high school students can study calculus well. They think calculus knowledge in students' brains is likely to become the “half-cooked food”, and this can produce a bad effect on the study of formal calculus at university. The authors consider that the emphasis of calculus in high school should be the intuitive understanding of fundamental calculus concepts, and it is also the basis of the understanding of formal concepts. Traditional mathematics course with chalk can't meet the needs of calculus teaching. The use of technologies can enhance the calculus teaching, especially the informal and visual calculus teaching, help students understand the underlying concepts. The authors describe how the use of technologies can improve the calculus teaching and learning, and point out that the use of technologies can clear up people's doubts.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제9권4호
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• pp.341-350
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• 2005

In this increasingly technological world, the creativity development has been highlighted much in many countries. In this paper, two mathematical activities with Chinese characteristics are presented to illustrate how to integrate algorithmic teaching into mathematical activities to develop students' creativity. Case studies show that the learning of algorithm can be transferred into creative learning when students construct their own algorithms in Logo environment rather than being indoctrinated the existing algorithms. Creativity development in different stages of mathematical activities and creativity development in programming are also discussed.

• 대한수학회보
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• 제49권6호
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• pp.1251-1254
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• 2012

Pure-strategy Nash Equilibrium (NE) is one of the most important concepts in game theory. Tae-Hwan Yoon and O-Hun Kwon gave a "sufficient condition" for the existence of pure-strategy NEs in matrix games [5]. They also claimed that the condition was necessary for the existence of pure-strategy NEs in undominated matrix games. In this short note, we show that these claims are not true by giving two examples.

• East Asian mathematical journal
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• 제22권1호
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• pp.93-109
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• 2006

The concept of intuitionistic fuzzy set was first introduced by Atanassov in 1986. In this paper, we define the intuitionistic(S,T)-fuzzy left h-ideals of a hemiring by using an s-norm S and a t-norm T and study their properties. In particular, some results of fuzzy left h-ideals in hemirings recently obtained by Jun, $\"{O}zt\"{u}rk$, Song, and others are extended and generalized to intuitionistic (S,T)-fuzzy ideals over hemirings.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제10권1호
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• pp.71-78
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• 2006

Gifted education has been becoming a focus of every field in Chinese society as a special educational mode, since Special Class for the Gifted Youth in the University of Science and Technology of China began to enroll students. In this paper we first introduce the developing procedure of the gifted education in China, and then recommend and analyze the characteristics of a successful gifted educational base in China. At length, we probe into the problems that exist in process of carrying on the gifted education in China for reference.

• 대한수학회보
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• 제42권2호
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• pp.245-256
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• 2005

We consider the second-order nonlinear difference equation (1) $$\Delta(a_nh(x_{n+1}){\Delta}x_n)+p_{n+1}f(x_{n+1})=0,\;n{\geq}n_0$$ where ${a_n},\;{p_n}$ are sequences of integers with $a_n\;>\;0,\;\{P_n\}$ is a real sequence without any restriction on its sign. hand fare real-valued functions. We obtain some necessary conditions for (1) existing nonoscillatory solutions and sufficient conditions for (1) being oscillatory.

• Interaction and multiscale mechanics
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• 제1권2호
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• pp.231-250
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• 2008

The statistical two-order and two-scale method is developed for predicting the mechanics parameters, such as stiffness and strength of core-shell particle-filled polymer composites. The representation and simulation on meso-configuration of random particle-filled polymers are stated. And the major statistical two-order and two-scale analysis formulation is briefly given. The two-order and two-scale expressions for the strains and stresses of conventionally strength experimental components, including the tensional or compressive column, the twist bar and the bending beam, are developed by means of their classical solutions with orthogonal-anisotropic coefficients. Then a new effective mesh generation algorithm is presented. The mechanics parameters of core-shell particle-filled polymer composites, including the expected stiffness parameters, minimum stiffness parameters, and the expected elasticity limit strength and the minimum elasticity limit strength, are defined by means of the stiffness coefficients and elasticity strength criterions for core, shell and matrix. Finally, the numerical results for predicting both stiffness and elasticity limit strength parameters are compared with the experimental data.