• Korean Journal of Mathematics
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• v.32 no.3
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• pp.507-520
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• 2024

In this manuscript, a new multi-valued contraction is defined from a combination of Jaggi-type hybrid contraction and Suzuku-type hybrid contraction. Conditions for the existence of fixed points for such contractions in metric space are investigated. Moreover, some consequences are highlighted and discussed to indicate the significance of our proposed ideas. An example is given to support the assumptions of our theorems.

• Journal of applied mathematics & informatics
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• v.23 no.1_2
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• pp.127-140
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• 2007

We present the boundary value problem (BVP) for the heave motion due to a vertical circular cylinder in water of finite depth. The BVP is presented in terms of velocity potential function. The velocity potential is obtained by considering two regions, namely, interior region and exterior region. The solutions for these two regions are obtained by the method of separation of variables. The analytical expressions for the hydrodynamic coefficients are derived. Computational results are presented for various depth to radius and draft to radius ratios.

• Journal of Communications and Networks
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• v.16 no.4
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• pp.415-420
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• 2014

Since the day the Internet became a common and reliable mechanism for communication and data transfer, security officers and enthusiasts rallied to enforce security standards on data transported over the globe. Whenever a user tries communicating with another recipient on the Internet, vital information is sent over different networks until the information is dropped, intercepted, or normally reaches the recipient. Critical information traversing networks is usually encrypted. In order to conceal the sender's identity, different implementations have proven successful - one of which is the invention of anonymous networks. This paper thoroughly investigates one of the most common and existing techniques used during data communication for avoiding traffic analysis as well as assuring data integrity - the onion router (TOR). The paper also scrupulously presents the benefits and drawbacks of TOR.

• Research in Mathematical Education
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• v.13 no.3
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• pp.235-250
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• 2009

Researchers at Truman State University in Missouri, located in the heartland of the United States, have been using materials adapted from the English translations of the sixth national primary mathematics curriculum from Korea for professional development and assessment with groups of Missouri teachers for the purpose of enhancing teachers' understanding of the fundamentals of mathematics since 2002 [gecKo Mathematics (2008). Korean Mathematics in American Classrooms. Edited by J. Grow-Maienza. Adapted from Korean Mathematics (2001). Kirksville, MO: Truman State University. http://kmath.truman.edu/]. A professional development initiative for 50 teachers conducted in Missouri this past year is reported here. Significant gains in teacher understanding of fundamental mathematics concepts and pedagogy necessary for student achievement in primary mathematics were found as a result of the initiative.

• Communications of the Korean Mathematical Society
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• v.13 no.2
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• pp.367-375
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• 1998

In this paper, we present the close solution for minimal hedging portofolis $II^*$ when payment f for American option admits the integral option.

• Bulletin of the Korean Mathematical Society
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• v.48 no.2
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• pp.413-426
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• 2011

Two types of new methods with variable time steps are proposed in order to valuate binary options efficiently. Type I changes adaptively the size of the time step at each time based on the magnitude of the local error, while Type II combines two uniform meshes. The new methods are hybrid finite difference methods, namely starting the computation with a fully implicit finite difference method for a few time steps for accuracy then performing a ${\theta}$-method during the rest of computation for efficiency. Numerical experiments for standard European vanilla, binary and American options show that both Type I and II variable time step methods are much more efficient than the fully implicit method or hybrid methods with uniform time steps.

• Journal of the Korean School Mathematics Society
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• v.1 no.1
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• pp.89-96
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• 1998

The purpose of this paper was to introduce 'The Third International Mathematics and Science Study'(TIMSS) to the mathematics education society in Korea, and to address current discussion about the TIMSS from the view of three Korean authors who are currently enrolled in an American university. This paper consisted of three parts: (1) The structure and organization of the TIMSS, (2) The analyses on test items from three populations of student groups, curricula and textbooks, questionnaires from students and teachers, video study, and case studies, (3) The discussion of various perspectives for mathematics education in Korea. The authors pointed out that the TIMSS was not just an international comparison study designed for ranking each of the 41 participating countries, but a study providing some insights for Korean mathematics education.

• Communications of the Korean Mathematical Society
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• v.30 no.3
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• pp.313-325
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• 2015

An H-magic labeling in a H-decomposable graph G is a bijection $f:V(G){\cup}E(G){\rightarrow}\{1,2,{\cdots},p+q\}$ such that for every copy H in the decomposition, $\sum{_{{\upsilon}{\in}V(H)}}\;f(v)+\sum{_{e{\in}E(H)}}\;f(e)$ is constant. f is said to be H-V -super magic if f(V(G))={1,2,...,p}. In this paper, we prove that complete bipartite graphs $K_{n,n}$ are H-V -super magic decomposable where $$H{\sim_=}K_{1,n}$$ with $n{\geq}1$.

• Journal of Educational Research in Mathematics
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• v.10 no.1
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• pp.115-137
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• 2000

In this paper, we tried to analyze 7 textbooks for liberal mathematics in elementary teacher's colleges in Korea and 3 foreign textbooks (2 American textbooks and 1 Japan textbook) which are believed to be used for pre-service education. We tried also to analyze in 3 lesson plans in homepages of Japan teacher's colleges. Next we tried to grope for syllabus of Mathematics for Elementary Teachers, and we suggested one syllabus. But we think that syllabus as a tentative one. So, it must be criticized by other researchers to be better one.

• School Mathematics
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• v.1 no.2
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• pp.433-449
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• 1999

This paper introduces a branch of qualitative method, called an in-depth interview method. By collecting data from the stories of Korean middle school students and a 9th grade American girl who used Geometer's Sketchpad and various software respectively for their mathematical problem solving, the qualitative analysis leads us to understand how such software affect their lives with mathematics subject. The unique characteristics and strands of each student's utterances reflect how software plays a role of learning aid for their mathematics learning. The arm of this study is both to get a good picture of each student's self-perceived relationship to mathematics as well as to explore external and objective parameters and factors in each student's internal situations. The qualitative descriptions of the collected data help us guide the students to the points where they could develop their interests and satisfaction with subject matter better. In this way, teachers may have more realistic understandings of how students become interested and motivated by mathematics, so that they are better able to find out ways of grasping the totalities of how the use of technology is interwoven into the school curricular.