• Proceedings of the Korean Institute of Building Construction Conference
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• 2002.05a
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• pp.31-36
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• 2002

Recently, more interests in surface treatment of structure with water repellent agent are steadily increased, But, investigation of its properties such as protection, durability, morphology of micro structure is not sufficient. Therefore, This paper is aimed for the investigation of water repellent property and change of morphology of micro pores in mortar that is treated by water repellent agent(Inorganic polymer based material). Water repellent property, water absorption coefficient, air permeability, porosity and the observation of micro structure was investigated in different water repellent agent type. The test results indicated that water repellent treated mortar showed low absorption coefficient and air permeability(breathing effect). This is why inorganic polymer is coated at the wall of capillary and micro pores, also, the volume of micro pore is reduced without the change of morphology in micro structure.

• International Journal of Costume and Fashion
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• v.17 no.1
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• pp.29-39
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• 2017

This study seeks to understand the consumer meanings of wearing classic styles. A qualitative research method was adopted, and 16 participants in the United States were interviewed and asked to define a classic fashion or style and why they wear one. Grounded theory was used for the research. The findings revealed three themes: (1) A classic style represents conservatism in style; (2) Style pragmatism refers to the positive attributes of wearing a classic style; and (3) consumers expect to continue to wear that classic style in the future. Those who are fashion-forward also expect to wear classic clothing in the future as they grow older. For people who do not follow fashion, classic is also a safe choice. The implications of these findings are discussed.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.8 s.227
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• pp.968-975
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• 2004

Nanofluids have anomalously high thermal conductivities at very low fraction, strongly temperature-dependent and size-dependent conductivities, and three-fold higher critical heat flux than that of base fluids. Traditional conductivity theories such as the Maxwell or other macroscale approaches cannot explain why nanofluids have these intriguing features. So in this paper, we devise a theoretical model that accounts for the fundamental role of dynamic nanoparticles in nanofluids. The proposed model not only captures the concentration and temperature-dependent conductivity, but also predicts strongly size-dependent conductivity. Furthermore, we physically explain the new phenomena for nanofluids. In addition, based on a proposed model, the effects of various parameters such as the ratio of thermal conductivity of nanofluids to that of a base fluid, volume fraction, nanoparticle size, and temperature on the thermal conductivities of nanofluids are investigated.

• Journal of the Korean School Mathematics Society
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• v.6 no.2
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• pp.127-142
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• 2003

This study was done to research and analyze the reasons why students feel anxious about learning mathematics. The aim of this study are to learn how to decrease the anxiety toward mathematics, and to find ways to give the learners confidence in their ability to study as well as increase their mathematical competence. The research method used was the development of a mathematics program through which the learners could have easy access to the mathematics to be studied.

• Journal of Engineering Education Research
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• v.20 no.4
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• pp.51-60
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• 2017

The purpose of this research is to analyze the educational experiences of competent engineering students and finding the reason why they invest their time and efforts engaging in school activities. Five students with high GPA, high K-CESA scores and successful employment or entrance test scores, participated in the survey and the interview. In checking their responses, their activities' records were gathered from school DB. According to the modified framework based on the personal investment theory, the interviews, survey and DB records were analyzed on the sense of self, the social cultural environment, and pattern of behaviors in schools. The competent engineering students are able to manage themselves, in maintaining a good relationship with the collegiate, and in having high self-efficiency. They also tend to put effort into their studies and participate in inbound and outbound school activities. At the last part, freshmen foundation, relationship within college, students' activity related future career, economic stability during studies are suggested for supporting students in universities.

• Journal of Environmental Impact Assessment
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• v.2 no.2
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• pp.55-58
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• 1993

After establishing the EIA(Environmental Impact Assessment) act in the Federal Republic of Germany there still remain methodical and substantial deficits. So nearly every environmental impact study went to be a matter of experiments. The requirement for standardization of data sampling and evaluation has permanently been increasing. This is meant to ensure quality standards for the assessment of environmental impacts as well as to maintain reliability required by the projecting company. Such a harmonization is of special importance because of the strongly accelerated expansion of traffic infrastructure caused by the reunification of Germany. That is why the guideline "EIA carried out" for the German Railways company is in process of development This guideline, focussing on practical demands, comprises impacts of railways, adequate sets of indicators, feasible tools for the prognosis and evaluation of environmental reactions. "EIA carried out" will be introduced not only as a manual but also through workshops and pilot studies.

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.3
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• pp.507-515
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• 2001

Tencel is a high quality cellulosic fiber, which is controlled and processed by an environmentally sound route. But, the point about tencel and the reason why it achieves its unique touch in its finished state is that it is a fibrillating fiber. That means it can take a great deal of punishment during the finishing process, which raise the fiber to produce the characteristics handle, without destroying the cloth. The aim of cellulase treatment is to improve appearence of tencel, plus the fiber ends protruding from the fabric surface. But enzymatic hydrolysis can weakens the fiber ends and changes the properties of fabrics. This study examined about the changes of properties according to several conditions and effect of cellulase to fibril of tencel. The results are as follows. The weight loss was occurred, tensile strength was decreased, softness was increased. And cellulase treatment reduced amount of fibril.

• Journal for History of Mathematics
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• v.17 no.1
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• pp.33-42
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• 2004

In this paper, we identify the essential ideas of Fundamental Theorem of Arithmetic(FTA). Then, we compare these ideas with several theorems of Euclid's Elements to investigate whether the essential ideas of FTA are contained in Elements or not. From this, we have the following conclusion: Even though Elements doesn't contain FTA explicitly, it contains all of the essential ideas of FTA. Finally, we assert two reasons why Greeks couldn't mention FTA explicitly. First, they oriented geometrically, and so they understood the concept of 'divide' as 'metric'. So they might have difficulty to find the divisor of the given number and the divisor of the divisor continuously. Second, they have limit to use notation in Mathematics. So they couldn't represent the given composite number as multiplication of all of its prime divisors.

• The Mathematical Education
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• v.39 no.2
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• pp.145-150
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• 2000

In this paper, we study the subject-matter knowledge related to the problem about rational exponent with negative bases. From the school mathematics point of view, we first investigate the meaning of the extensions of the number systems. We analyze the intrinsic meaning involved in the (-8)$^{1}$ 3) through the natural interpretation of rational exponent with negative bases by the complex number. we explain why it is important for a teacher to have the subject-matter knowledge in order to detect and correct student\`s mistake and misunderstanding.

• Asia pacific journal of information systems
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• v.10 no.3
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• pp.41-59
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• 2000

The role of information systems(IS) is far more important in business operations today. Managers recognize information as a major resource of the organization, and non-expert end users positively participate in information system development processes. This phenomenon is considered user-led information system development(ULD), where users define the information requirements, oversee system testing, manage system development, and lead the overall project. Based on a socio-technical approach, this study examines the impact of ULD on IS success. This paper also investigates the moderating effects of various contextual factors on the relationships between ULD and the success. The questionnaire was developed and the data was collected from the end users who participated in implementing ERP systems. The results showed that ULD positively affects the success. For the moderating variables, IT complexity was found to have a strong effect on the relationship between ULD and the success while business complexity and top management support have partial effects. Surprisingly, resource adequacy was not found to have the effect. This study provides academia and practitioners with a number of implications and guidelines regarding why and when to introduce ULD in their IS development initiatives.