• The Journal of the Korea Contents Association
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• v.16 no.4
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• pp.179-194
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• 2016

The purpose of this study is to find out how the reconstructed textbook for vocational high school students influences on students' scholastic achievement and affective domain when it is used in the class of vocational high school. To tackle the study problems, the researcher chose two classes of the first grade in G commercial high school and gave lessons to each of the two classes; one class, as an experimental group, was taught with the reconstructed textbook and the other, as a comparative group, was taught with the original textbook. The following results are derived from the study. First, it turned out in the post academic achievement test result, there is no significant difference between the experimental group and the comparison group, by significant level; .05. However, the prior academic achievement test result shows that the average of the comparison group is 0.44 points higher than the average of the experimental group, while the post test result shows that the average of the experimental group is 1.96 points higher than the average of the comparison group. Second, it turned out by the post affective domain test result, there is no significant difference between the experimental group and the comparison group, by significant level; .05, and any significant difference did not occur in all five areas. However, the whole point of the affective domain and the points of each area of experimental group are higher than those of the comparison group, and the degree of improvement in experimental group is also greater than that of the comparison group. In conclusion, the effectiveness of utilizing a reconstructed textbook in vocational high school math class can be expected in the long term.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.219-220
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• 2009

The PillPose of this study, powder containing the recycled fine aggregate is appropriate for developing high strength and liquidity, the characteristic of the SCC and it was increased the ratio of mixing the recycled fine aggregates resulted from waste concrete and the natural fine aggregates by 25%, making differential in total 5 levels and applied to SCC. After all, this study was reviewed the physical properties of the fresh concrete, mechanics and durability of the hardened concrete and tried to ensure the possibility of utilizing the recycled fine aggregates as a material for SCC.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.53-54
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• 2014

By using geometrical structure of Fresnel lens, it can be applied with receiver antenna and geodetic system. In this paper, radiation pattern from fresnel lens array of Soret type is calculate by the FDTD method. For simplicity, fresnel lens should be located linearly and considered to be dielectric rod with a relative permittivity.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.43-44
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• 2014

By using geometrical structure of Fresnel lens, it can be applied with receiver antenna and geodetic system. In this paper, we consider Soret typed fresnel lens with reflected plate and its focusing gain characteristics is calculated by the FDTD method.

• Korean Journal of Social Welfare Studies
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• v.44 no.2
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• pp.359-385
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• 2013

The study looked into the effect of internet utilization (utilization frequency and utilization ability in internet) on the life satisfaction level for the elderly in depth. In order to verify the correlation of two variables, a mediating model structured by ego integrity was used which gave out the Seoul welfare panel data created by Seoul welfare foundation in 2010. The total sample size was a group of 1862 elders aged over 60. When it came to our research methods, structured equation analysis was applied to verify the mediating effect and theoretical background. The findings are as follows: First, elderly's utilization frequency in internet is not an influencing factor to life satisfaction and elderly's utilization ability in internet is an influencing factor to life satisfaction. Second, the level of social activity did function as partial mediator on relationship between elderly's utilization ability in internet and life satisfaction. This study indicates theoretical and practical interventions to promote elderly's utilization in internet.

• Journal of the Korean School Mathematics Society
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• v.17 no.4
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• pp.697-716
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• 2014

The purpose of this paper is to investigate high school students' learning characteristics which revealed in their learning process of limit using GeoGebra. And we are going to analyze effects of teaching of limit using GeoGebra to high school students' interesting and attitudes for mathematics learning. To do this, we selected three high school students as participants and ask them performing limit learning using GeoGebra. We recorded their problem solving process. Through analyzing their problem solving process relate to their solution, we found the followings: First, students did not logically approach based on mathematical properties or given materials, rather showing tendency decide with self-conscious and intuition. Second, it is possible that former reasoning strategies disturb following reasoning in the process of high school students' mathematics learning. Third, learning process of limit using GeoGebra help high school students to identify and correct their errors relate to limit learning. Forth, learning process of limit using GeoGebra positively effects to high school students' interesting and attitudes for mathematics learning.

• Information Systems Review
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• v.23 no.4
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• pp.69-86
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• 2021

As artificial intelligence technology advances, personalized recommendation systems using big data have attracted huge attention. In the case of beauty products, product preferences are clearly divided depending on customers' skin types and sensitivity along with individual tastes, so it is necessary to provide customized recommendation services based on accumulated customer data. Therefore, by employing deep learning methods, this study proposes a neural network-based recommendation model utilizing both product search history and context information such as gender, skin types and skin worries of customers. The results show that our model with context information outperforms collaborative filtering-based recommender system models using customer search history.

• The Journal of the Korea Contents Association
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• v.20 no.11
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• pp.15-27
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• 2020

In the design process that focuses on problem solving, in general, two or three barriers to design creativity appear at the same time and are linked to increase difficulty. Because the design problem always arises in unusual, unique, weird, and difficult to define, it is not possible to extract the correct answer through the formula and the answer is always plural. This study aims to present solutions and prove their effectiveness as a follow-up study that seeks to overcome the representative obstacles to design creativity discussed in the previous study. To this end, a qualitative study was conducted to find solutions to the obstacles suggested in the previous study and to devise key solutions(creativity development cards). At the same time, a quantitative research methodology using experiments and statistical analysis was adopted. After grasping the core characteristics of an object using the creativity development card, it was able to approach the creative solution by utilizing the reductive analysis of the original such as transformation of the core characteristics, reconsideration of essential problems and intentional differentiation. As a result, it was confirmed that the proposed solutions were effective not only as a method of overcoming the barriers to design creativity, but also in improving creativity.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.4
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• pp.439-445
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• 2008

Sawdust is considered one of the cheapest and abundantly available adsorbents, and it is not necessary to regenerate. The spent sawdust can be incinerated or reused as a fuel. The sawdust adsorption can be applied to the removal of color and metal cations from the wastewater. The aim of this study was to evaluate the adsorptive capacities of sawdust with respect to color, COD, SS, turbidity, metal cation from textile wastewater. Langmuir, Freundlich, BET and Sips adsorption isotherm were obtained for the sawdust adsorption of Fe(III). The effects of particle size and amount of sawdust on the adsorption of Fe(III) were also studied. COD, SS, color, turbidity and Fe(III) removal efficiencies were examined at the continuous fixed-bed adsorption test. It was showed the removal efficiencies of SS 50.0%, Fe(III) 25.0%, turbidity 79.4%, color 48.6% and COD 50.9%. In addition, the changes of surface structure between before and after adsorption were investigated through SEM analysis. It is confirmed that the waste sawdust can be successfully used as an adsorbent for wastewater treatment.

• Journal of the Korean GEO-environmental Society
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• v.3 no.1
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• pp.27-36
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• 2002

This study is about the applicability of copper slag as the ground improvement material. By the geo-technical characteristics of the copper slag and by the effect of consolidation and under drainage condition, it is proved that the copper slag can be used for ground improvement material as substitution for sand. As a result of laboratory tests, it was shown that the permeability of the copper slag was similar to that of sands under the vertical drainage condition. In addition, the copper slag showed higher critical hydraulic gradient than that of sand under up-ward vertical flow state. The copper slag has potential safety against piping and it has internal stability of particles. The conclusion is that the copper slag is suitable for drainage and filter material.