• Journal of the Korea Convergence Society
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• v.6 no.1
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• pp.49-55
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• 2015

In the FTA environment, it is necessary to comply with the rules of origin in order to receive duty-free benefits. To do this, they have to precede the Harmonized System(HS) tariff classification of the goods and understand thoroughly the basic principles that constitute the tariff schedule of HS classification. For the correct classification, they should understand exactly the product name of "Heading" about the items, "Legal Note" in the relevant "Section" or "Chapter" as well as provisions of the commentary. Therefore, this paper proposes to develop a HS classification services based on the performance system of knowledge convergence of field terms commonly used in various industries. In result, our services can provide users the conveniences which users first selects one of seven decision elements of the classification and perform the classification easily and accurately.

• Journal of the Korea Convergence Society
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• v.8 no.10
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• pp.173-183
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• 2017

The purpose of this study is to develop students' creativity and artistic sensitivity by developing a convergence education program that links various subjects, including mathematics, science, and art based on design. Design is done in almost every human activity that pursues beauty and implements cultural value through patterns and images. We have developed three programs for elementary school students and two programs for middle school students, taking into consideration the achievement standards and curriculum content appropriate for the 2015 revised curriculum. It was assessed by a panel of five educational experts during the development and demonstration courses to evaluate the feasibility of the development program. The development program can enhance the design literacy and design sense of elementary and junior high school students and can be used convergent educational contents that can be applied in the free-semester system activities of junior high school. Through this program, adolescents who will lead the future design society will be able to acquire the sense of design, literacy, and design ability as design consumers and producers.

• Applied Chemistry for Engineering
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• v.24 no.5
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• pp.476-482
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• 2013

In this work, the effects of electrochemical oxidation of carbon fiber surfaces on mechanical interfacial properties of carbon fibers-reinforced polarized-polypropylene matrix composites were studied with various current densities during the treatments. Surface properties of the fibers before and after treatments were observed by SEM, AFM, XPS, and contact angle measurements. Mechanical interfacial properties of the composites were measured in terms of critical stress intensity factor ($K_{IC}$). From the results it was found that $O_{1s}$ peaks of the fiber surfaces were strengthened after electrochemical oxidation which led to the enhancement of surface free energy of the fiber, resulting in good mechanical performance of the composites. It can be concluded that electrochemical oxidation of the carbon fiber surfaces can control the interfacial adhesion between the carbon fibers and polarized-polypropylene in this composites system.

• Journal of the Korea Convergence Society
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• v.9 no.1
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• pp.405-418
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• 2018

This paper was carried out to provide basic data for career search of the free school system. Putting the goal of career education into cultivating expertise, the review was made on the results of the previous studies on the requirements of professional practice. However, As the controversy over the requirements of professional practice has not been solved, so the core elements related to expert performance were examined as a whole through a fundamental cognitive mechanism from which diverse human cognitive characteristics appear. The results show that expert domains consists of content and representation that can exist in an integrated to a great variety of combinations between the two or independent manner, and each domain or field expert performance require different levels of the elements such as intelligence, internal thinking, curiosity (motivation), and obsession (task commitment); and the birth of 1% experts in a domain or field is determined by the obsession. Based on the results, this paper discusses issues related to professionalism and provides a concrete approach to career search during the free semester.

• Journal of the Korea Convergence Society
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• v.8 no.3
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• pp.283-294
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• 2017

This study developed and proposed a cosmetics education program for middle school students for the free semester policy. The program was conducted for 20 sessions, two hours per week, based on theories and practice, and the teaching-leaning plan was made in the order of introduction, development, and summary. Through the program, students will have an opportunity to recognize the problems of misusing cosmetics and importance of the skin. Also, the program was developed in a way that encourages students to actively participate in the education so that it can lead to career development in the social and technical aspects. This study can provide basic data for students to acquire knowledge and practical education related to skincare and cosmetics use in the future.

• Nuclear Engineering and Technology
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• v.31 no.2
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• pp.214-225
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• 1999

An accurate method is presented for flexural vibrations of sectorial plates having simply supported-free and free-free radial edges, when the circular edge is either clamped or simply supported. The classical Ritz method is employed with two sets of admissible functions assumed for the transverse vibratory displacements. These sets consist of : (1) mathematically complete algebraic-trigonometric polynomials which gurantee convergence to exact frequencies as sufficient terms are retained, and (2) comer functions which account for the bending moment singularities at re-entrant comer of the radial edges having arbitrary edge conditions. Accurate (at least four significant figures) frequencies and normalized contours of the transverse vibratory displacement are presented for the spectra of corner angles [90$^{\circ}$, 180$^{\circ}$(semi-circular), 270$^{\circ}$, 300$^{\circ}$, 330$^{\circ}$, 350$^{\circ}$, 355$^{\circ}$, 360$^{\circ}$ (complete circular)] causing a re-entrant comer of the radial edges. Future solutions drawn from alternative numerical procedures and finite element techniques may be compared with these accurate results.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2000.04a
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• pp.140-145
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• 2000

The spectral method which is composed of an eigenfunction expansion of free modes in the wave number domain is used to produce two dimensional unsteady inviscid wave simulation such as progressive waves in a numerical pneumatic wave tank. A spatial and time dependent free surface elevation and the potential are calculated by integrating ODE derived from fully nonlinear kinematic and dynamic free surface boundary condition at each time step. The nonlinear characteristics in the waves by this method were notable as increasing wave steepness. This method is very useful and powerful in terms of saving computational time caused by rapid convergence exponentially with increasing number of nodes, even preserving accurate numerical results. Moreover, it will given us many possibilities to apply to naval and ocean engineering fields.

• Applied Science and Convergence Technology
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• v.23 no.6
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• pp.345-350
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• 2014

The surface oxidation mechanism of lead-free solder alloys has been investigated with multiple reflow using X-ray photoelectron spectroscopy. It was found that the solder surface of Sn-Ag-Cu-In solder alloy is surrounded by a thin $InO_x$ layer after reflow process; this coating protects the metallic surface from thermal oxidation. Based on this result, we have performed a wetting balance test at various temperatures. The Sn-Ag-Cu-In solder alloy shows characteristics of both thermal oxidation and wetting balance better than those of Sn-Ag-Cu solder alloy. Therefore, Sn-Ag-Cu-In solder alloy is a good candidate to solve the two problems of easy oxidation and low wettability, which are the most critical problems of Pb-free solders.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2558-2561
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• 2008

In the present study, a parallel Taylor-Galerkin/level set based two-phase flow code was developed using finite element discretization and domain decomposition method based on MPI (Message Passing Interface). The proposed method can be utilized for the analysis of a large scale free surface problem in a complex geometry due to the feature of FEM and domain decomposition method. Four-step fractional step method was used for the solution of the incompressible Navier-Stokes equations and Taylor-Galerkin method was adopted for the discretization of hyperbolic type redistancing and advection equations. A Parallel ILU(0) type preconditioner was chosen to accelerate the convergence of a conjugate gradient type iterative solvers. From the present parallel numerical experiments, it has been shown that the proposed method is applicable to the simulation of large scale free surface flows.

• Steel and Composite Structures
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• v.6 no.4
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• pp.353-366
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• 2006

The discrete singular convolution (DSC) algorithm for determining the frequencies of the free vibration of single isotropic and orthotropic laminated conical shells is developed by using a numerical solution of the governing differential equations of motion based on Love's first approximation thin shell theory. By applying the discrete singular convolution method, the free vibration equations of motion of the composite laminated conical shell are transformed to a set of algebraic equations. Convergence and comparison studies are carried out to check the validity and accuracy of the DSC method. The obtained results are in excellent agreement with those in the literature.