• Spatial Information Research
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• v.20 no.1
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• pp.1-7
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• 2012

Hiking on the mountain is one of the most popular recreations for modern people, but many people have trouble because they select a wrong hiking trails with their own ability and this w ill be just a danger accident. It was suggested that slope analysis of hiking trails using GIS for solving this problem, and the proposed method is faster and easier than the other method. Also the slope of many hiking trails which have same destination was classified by analysing and comparing, then citizen can choose right hiking trails with their own ability.

• International Journal of Human Ecology
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• v.8 no.2
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• pp.1-16
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• 2007

The authors examined how Korean housewives manage family resources, make decisions, handle pressures, and negotiate the constraints of everyday life in a society that places unrealistic expectations upon them. The authors approached housewives by imagining them as thinking, strategizing, and problem-solving individuals, who are capable of speaking for themselves and making choices within situational and personal limits. Eleven full-time housewives were interviewed on how they experience their marriages, children, families, and society. Their narratives were then analyzed to sort out the strategies the women employed to maintain their identities. The narratives showed women's will and agency as they worked to resolve the contradictions in their daily life, and revealed individual differences within this group of women who are often seen as homogenous.

• Journal of applied mathematics & informatics
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• v.4 no.1
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• pp.83-108
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• 1997

Chebysheff-Halley methods are probably the best known cubically convergent iterative procedures for solving nonlinear equa-tions. These methods however require an evaluation of the second Frechet-derivative at each step which means a number of function eval-uations proportional to the cube of the dimension of the space. To re-duce the computational cost we replace the second Frechet derivative with a fixed bounded bilinear operator. Using the majorant method and Newton-Kantorovich type hypotheses we provide sufficient condi-tions for the convergence of our method to a locally unique solution of a nonlinear equation in Banach space. Our method is shown to be faster than Newton's method under the same computational cost. Finally we apply our results to solve nonlinear integral equations appearing in radiative transfer in connection with the problem of determination of the angular distribution of the radiant-flux emerging from a plane radiation field.

• Proceedings of the Korea Society of Mathematical Education Conference
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• 2010.04a
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• pp.83-97
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• 2010

The purposes of this study were to explore in depth about 5th graders' mathematical speaking and writing abilities and to investigate differences on those abilities. The study involved 3 5th graders and their speaking and writing abilities in geometry area were analyzed. According to the results of the study, the children had difficulties in selecting and using appropriate mathematical languages to explain mathematical concepts, mathematical ideas, and problem solving steps. The children who participated in the study showed higher ability in speaking than writing.

• The Mathematical Education
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• v.48 no.1
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• pp.33-45
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• 2009

The purpose of this article is to study characteristics of Soma Cube in combinatorial-geometric point of view, and to present basic substances and direction for efficient Soma cube activities in school mathematics upon systematical analysis of methods of finding solutions using Inclusion-Exclusion Method. We can apply Inclusion-Exclusion Method to find all possible solutions in Soma Cube activities not as trial-and-error method but as analytical method. Because Inclusion-Exclusion Method can reduce the number of problem-solving variables by making high conjunction in the choice of pieces. Soma cube pieces can be sorted as 'flat' ones and 'non-flat' ones, which would be another effective method in the manipulation of Soma Cube pieces.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.3
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• pp.538-550
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• 2004

The convection heat transfer coefficients on the top surface of a large liquid petroleum liquid injection(LPLi) engine piston with the oil gallery are analyzed by solving an inverse thermal conduction problem. The heat transfer coefficients are numerically found so that the difference between analyzed temperatures from the finite element method and measured temperatures is minimized. Using the resulting heat transfer coefficients as the boundary condition, temperature of a large LPLi engine piston is analyzed. With varying cooling water temperature, temperature, stress, and thermal expansion of the piston are analyzed and evaluated.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.6
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• pp.1421-1429
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• 1994

An algorithm is developed for solving the inverse kinematic problem of a 6-degree-of-freedom robot with a wrist offset for which the closed form inverse solutions are not obtainable, but knowledge of one joint variable allows closed form solutions of the remaining joint variables. The algorithm does not require Forward Kinematics nor Jacobian but uses the implicit kinematic relationships between joint variables and the given hand position. An iterative back substitution method is used to solve the inversion and the optimal conditions of the convergence are incoporated. An example is given to illustrate the concepts, the solution procedure and its convergency.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.247-254
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• 2003

The lightness of components required in automobile and machinery industry is requiring high strength of components. In particular manufacturing process and new materials development for solving the fatigue fracture problem attendant upon high strength of suspension of automobile are actively advanced. In this paper, the effect of compressive residual stress of spring steel(JISG SUP-9) by shot-peening on fatigue crack growth characteristics in high temperatures($100^{\circ}$, $150^{\circ}$, $180^{\circ}$) was investigated with considering fracture mechanics. So, we can obtain followings. (1)Compressive residual stress decreases in high temperature, that is, with increasing temperature. (2)The effect of compressive residual stress on fatigue crack growth behavior in high temperature increases below ${\Delta}K=17{\sim}19MPa$ (3)It was investigated by SEM that the constraint of compress residual stress for plastic zone of fatigue crack tip was decreased in high temperature as compared with room temperature.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1441-1446
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• 2003

The design optimization of the plate heat exchanger with staggered pin arrays for a fixed volume is performed numerically. The flow and thermal fields are assumed to be a streamwise-periodic flow and heat transfer with constant wall temperature and they are solved by using the finite volume method. The optimization is carried out by using the sequential linear programming (SLP) method and the weighting method is used for solving the multi-objective problem. The results show that the optimal design variables for the weighting coefficient of 0.5 are as follows; S=6.497mm, P=5.496mm, $D_1=0.689mm$, and $D_2=2.396mm$. The Pareto optimal solutions are also presented.

• Journal of the Korean School Mathematics Society
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• v.13 no.4
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• pp.499-524
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• 2010

In this paper, we applied NIE(Newspaper In Education) to the course of study for statistics unit of elementary mathematics which can improve students' abilities of concept of statistics, analyzing data and problem solving so they can do these with direct activity by themselves and find out how NIE effects on children's learning achievement for statistics unit and more effective solution for the course of study for elementary mathematics.