• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.565-566
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• 2009

Supplementary cementing materials (SCM), such as silica fume, slag, and low-calcium fly ash, have been widely used as mineral admixtures in high strength and high performance concrete. Due to the chemical and physical effect of SCM on hydration, compared with Portland cement, hydration process of cement incorporating SCM is much more complex. This paper presents a numerical hydration model which is based on multi-component concept and can simulate hydration of cement incorporating SCM. The proposed model starts with mixture proportion of concrete and considers both chemical and physical effect of SCM on hydration. Using this proposed model, this paper predicts the following properties of hydrating cement-SCM blends as a function of hydration time: reaction ratio of SCM, calcium hydroxide content, heat evolution, porosity, chemically bound water and the development of the compressive strength of concrete. The prediction results agree well with experiment results.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.126-127
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• 2016

In this research, the optimum combination of fly ash (FA) and blast furnace slag (BS) was deduced by analyzing the performance of high volume supplementary cementitious materials (SCMs) cement mortar depending on various combinations of cement, FA, and BS. As a result, increased workability was shown with increased the portion of FA, while air content, setting time, and compressive strength were decreased.

• The International Journal of Costume Culture
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• v.4 no.1
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• pp.9-17
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• 2001

The purposes of the study are to find out the effect of clothing colors on perception of stimulus ages, occupations and images using stereotyping and color vision theories. The research method is a qualitative study and materials developed for the study are a set of stimuli and open-ended responses. The subjects were 1138 undergraduate students in Taejoen city, Chungbuk province. The data is analyze using content analysis, supplementary frequency and χ²analysis. The results are as follows : 1) The colors in Korean traditional costumes affected on the wearer's age perception : The red ensemble give the wearer the youngest look while the gray give the oldest look. 2) Mono-color ensemble wearers tend to give older look than bi-color ensemble wearers. 3) The chima colors and the jogori colors have similar impact on the wearer's age perception. 4) On image perception the jogori colors have more impact than the chima colors. 5) The colors in Korean traditional costumes are the clues to estimate the wearer's occupation.

• Journal of Fashion Business
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• v.25 no.3
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• pp.51-70
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• 2021

The study aims to evaluate changes in textiles for automotive interior and suggest directions that the textile-development should take in order to achieve sustainability, and enter a circular economy system in the future. The main content and results of the study are as follows: First, we cover the overall sustainability study in the fashion and textile fields; in particular, the certification system is well established through the provision of information on the whereabouts of products to consumers and verification by external environmental auditors. Second, we considered the criteria of C2C in order to derive the necessary criteria for sustainability certification in the field of textiles. Third, we looked at the latest development trends of textile materials for automobile interiors which were divided into three categories: natural originated materials, circular economic consideration materials, and functional supplementary lightweight materials. In addition, we identified to what extent the trend of changes aggregated in the examples was satisfied and what was lacking when applied to the Basic criterion of C2C. As such, this study links and applies the sustainability criteria pursued in the fashion and textile fields to the textile for automotive interior materials, suggesting a direction for the textile field for automotive internal materials in the future. Based on the results of this study, it is hoped that studies on textiles for automotive interior considering the net economy will continue, and practical development in the industry will be realized.

• Journal of The Korean Association For Science Education
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• v.16 no.3
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• pp.303-313
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• 1996

The major purpose of this thesis is to construct the evaluating framework of a science textbook with a high confidence and universal validity, referring to a preceeding study and materials involved in research work, and in consideration of the educational conditions of the secondary school. The framework developed in this study are composed of 7 categories: content, organization, representation, laboratory, illustrations, external form or editing system, and supplementary materials. Each category consists of detailed items. Eech item in the check-list is to be given between one and five points, and the total number of possible points in this evaluating framework is 290. As a result, these evaluating items enable quantitative analyses, afford an opportunity which we can look into many-sidedly the respects we should consider when a science textbook is adopted, and they can be estimated partly or synthetically as occasional demands. This study is exepected to contribute to choose a good science textbook as fundamental data in the future, and to help the lasting study or estimation of the textbook.

• Carbon letters
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• v.23
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• pp.9-16
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• 2017

This paper introduces a nitrogen-doped ordered mesoporous carbon (NOMC) derived from glucosamine with hybrid capacitive behaviors, achieved by successfully combining electrical double-layer capacitance with pseudo-capacitance behaviors. The nitrogen doping content of the fabricated NOMC reached 7.4 at% while its specific surface area ($S_{BET}$) and total pore volume reached $778m^2g^{-1}$ and $1.17cm^3g^{-1}$, respectively. A dual mesoporous structure with small mesopores centered at 3.6 nm and large mesopores centered at 9.9 nm was observed. The specific capacitance of the reported materials reached up to $328Fg^{-1}$, which was 2.1 times higher than that of pristine CMK-3. The capacitance retention rate was found to be higher than 87.9% after 1000 charge/discharge cycles. The supplementary pseudocapacitance as well as the enhanced wettability and conductivity due to the incorporation of nitrogen heteroatoms within the carbon matrixes were found to be responsible for the excellent capacitive performance of the reported NOMC materials.

• 대한공업교육학회지
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• v.34 no.1
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• pp.44-86
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• 2009

The major purposes of this study were 1) to present a desirable guideline for writers who would develop the new Introduction-to-Industry textbook through the comparative analysis of 4 different kinds of current Introduction-to-Industry textbooks, 2) to help educators, who make national college entrance exam in the vocational inquiry area, make good exam items with the results of the study, and 3) to offer effective methods of teaching and learning in the field of industrial education with them. Research method used in this study was mainly literature review with the scrutinization of the literature related to the Introduction-to-Industry textbooks. Results of this study showed that all textbooks compared do mostly comply with the national writer's specific guidelines for the Introduction-to-Industry textbooks. However there were varieties for the all textbooks in a sense of deployment balance for the contents of the textbook chapters. There were also considerable differences for the deployment of supplementary materials, evaluative materials, visual materials and etc. according to the characteristics of each textbook. The degree of the connectivity between the textbooks and the national college entrance exam in the area of the vocational inquiry was similar for the each textbook. However, it was not good enough for the students to study one textbook for the preparation of the exam in the vocational inquiry area because the problems in the exam were set in the range of covering the all different kinds of textbooks by the examiners.

• Journal of Korea Society of Waste Management
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• v.35 no.8
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• pp.721-730
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• 2018

We investigated the effects of heavy metals in cement in the last 3 years and the amount of waste in the cement manufacturing process. The result shows that the average $Cr^{6+}$ content in cement products is controlled at 10 mg/kg. Cu and Pb have lower detection tendency in white cement than in ordinary portland cement. In addition, heavy metals such as Cd show a certain level of detection regardless of the input wastes. Copper slag and phosphate gypsum are the main influencing factors on the heavy metals in cement products. In auxiliary fuels, plastics waste and wood waste are considered to affect heavy metals in cement products. Alternative raw materials are considered to be affected by the alternative raw materials managed as byproducts. In the case of supplementary fuels, auxiliary fuels managed as waste instead of auxiliary fuels managed as byproducts affect the heavy metals in cement. This study examined the input amount without considering the heavy metals in each waste. Therefore, the result may vary in different situations, and further research must be conducted to supplement the findings. However, if the heavy-metal contents in the waste are constant, it can be used as a reference material for the control of heavy metals in cement products.

• Advances in Computational Design
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• v.3 no.3
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• pp.289-302
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• 2018

The use of optimum content of supplementary cementing materials (SCMs) such as limestone filler (LF) to blend with Portland cement has been resulted in many environmental and technical advantages, such as increase in physical properties, enhancement of sustainability in concrete industry and reducing $CO_2$ emission are well known. Artificial neural networks (ANNs) have been already applied in civil engineering to solve a wide variety of problems such as the prediction of concrete compressive strength. The feed forward back propagation (FFBP) algorithm and Tan-sigmoid transfer function were used for the ANNs training in this study. The training, testing and validation of data during the backpropagation training process yielded good correlations exceeding 97%. A parametric study was conducted to study the sensitivity of the developed model to certain essential parameters affecting the compressive strength of concrete. The effects and benefits of limestone filler on hardened properties of the concrete such as compressive strength were well established endorsing previous results in the literature. The results of this study revealed that the proposed ANNs model showed a high performance as a feasible and highly efficient tool for simulating the LF concrete compressive strength prediction.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.46-47
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• 2018

High performance concrete with low water-to-cement ratio has been widely used with increased demand of high rising buildings and huge scaled structures. Additionally, for high performance concrete, various SCMs are replaced to improve its performance from fresh state to hardened state. With the drawback of increased viscosity of the concrete mixture for high performance concrete, low-viscosity typed high range water reducer is the relatively new admixture. Therefore, as a goal of the research, under using various SCMs with wide range of content, the performance of low-viscosity typed high range water reducer was evaluated. Especially, in this research, the influence of low-viscosity typed high range water reducer on rheological properties including plastic viscosity and yield stress were assessed. As a result of the research, it is expected to provide a fundamental information of low -viscosity typed high ranged water reducer on high performance concrete with various conditions of SCMs.