• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.743-745
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• 1998

SCT thin films were deposited with substitutional contents of Ca using RF magnetron sputtering method, and the structural and dielectric properties are investigated. SEM and XRB were examined to analysis of structural characteristics. The crtstallinity of SCT thin films and dielectric constant were increased at Ca 15[mol%]. While, it was decreased when the substitutional contents of Ca exceed over 15[mol%].

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.472-473
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• 2007

The $(Sr_{1-x}Ca_x)TiO_3$(ST) thin films are deposited on Pt-coated electrode(Pt/TiN/$SiO_2$/Si) using RF sputtering method with substitutional contents of Ca. The maximum grain of thin films is obtained by substitution of Ca at 15[mol%]. Also, the composition of ST thin films were closed to stoichiometry(1.081~1.117 in A/B ratio). The dielectric constant changes almost linearly in temperature ranges of -80~+90[$^{\circ}C$]. The current-voltage characteristics of ST15 thin films showed the increasing leakage current as the measuring temperature increases.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.456-459
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• 2005

Continuous cooling transformation behaviors were studied fur low carbon HSLA steels containing three different level $(1\~3\;wt\%)$ of Ni addition. Thermo-mechanical processing (TMP) simulations to construct continuous cooling (CCT) diagram were conducted by using Gleeble system. As cooling rate increased, pearlite, granular bainite, acicular ferrite, bainitic ferrite and lath martensite were transformed from deformed austenite. Fully bainitic microstructure were developed at all cooling rate condition in high Ni containing steel due to hardenability increasing effects of Ni. Ni also influenced the transformation kinetics. At the slowest cooling rate of $0.3^{\circ}C/s$, transformation delayed with decreasing Ni contents because of the diffusion of substitutional alloy elements. However, cooling rate slightly increased to $1^{\circ}C/s$, transformation kinetics accelerated with decreasing Ni contents because nucleation of bainite was sluggish due to hardening of residual austenite.

• Journal of the Korean Ceramic Society
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• v.34 no.11
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• pp.1099-1106
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• 1997

In the present study, the effect of TiB2 addition on the sintering behavior of ZrB2 ceramics was studied with hot pressing under Ar atmosphere. Hot pressing experiments were carried out in graphite dies at the 1$700^{\circ}C$, 180$0^{\circ}C$ under Ar atmosphere. The sintering density increased with increasing TiB2 contents. With the addition of 10wt% TiB2 almost theoretical density could be achieved by hot-pressing at 180$0^{\circ}C$. Zr-Ti-Fe-B compound in liquid phase was observed from the EDS and WDS analysis. It was considered that sinterability was enhanced due to the mass transfer through liquid phase formed at the sintering temperature. In addition of TiB2, transition metal of groups IV, substitutional solid solution could be formed.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.237-238
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• 2010

The purpose of this research is to develop the method for the beneficial use of dredged material. In this research, authors investigate the material properties of dredged material contained with dredge material of various contents. The compressive strength of cement mortar with 10% dredged material from the Busan harbor is slightly higher than it of conventional mortar, but, it is to need to further research for developing the application technique on the dredged material as the substitutional material of a sand.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.325-329
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• 1998

In this paper, the (Sr$_{1-x}$ Ca$_{x}$)TiO$_3$(SCT) thin films were deposited at various substrate temperature using RF magnetron sputtering method on optimized Pt-coated electrodes (Pt/TiN/SiO$_2$/Si). An influence of substrate temperature and annealing temperature on the structural and dielectric properties are investigated. The substrate temperature changed from 100[$^{\circ}C$] to 500[$^{\circ}C$] and crystalline SCT thin films were deposited abode 400[$^{\circ}C$]. All thin films had (111) preferred orientation, the (100) oriented films were obtained at the substrate temperature above 400[$^{\circ}C$]. The dielectric constant changes almost linearly in the temperature region of -80~+90[$^{\circ}C$], the temperature characteristics of the dielectric loss exhibited a stable value within 0.1, then not affected by substitutional contents. The capacitance characteristics appears a stable value within $\pm$5[%].

• Nutrition Research and Practice
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• v.10 no.4
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• pp.424-432
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• 2016

BACKGROUND/OBJECTIVES: Most consumers are able to recognize allergenic foods. However, the frequency of checking such foods is reportedly low, resulting in higher prevalence of food-related allergic reactions in Korea compared to other countries. Thus, this study was performed to investigate the overall perception of allergenic food labeling and its practice level in food manufacturing company employees. SUBJECTS/METHODS: The survey was administered to food safety employees and food development teams at food companies located in metropolitan areas. A total of 399 (93.8%) valid samples were used in the final analysis. Statistical analyses, including Frequency Analysis, t-test, Anova, PCA (Principal Component Analysis), and Pearson Correlation Analysis using SPSS ver. 21.0, were performed. RESULTS: The correct answer rate in the analysis of allergy-related knowledge level ranged from 15.0% to 89.7%. Analysis of differences in allergy-related perception by knowledge level showed significant differences in introduction of a food recall system, strengthening of relevant laws and regulations, content labeling, description of substitutional food, and differentiated package by age. CONCLUSIONS: It can be concluded that labeling of allergenic foods should be made easier and more convenient for checking by employees, developers, and consumers, and it is necessary to provide contents through the development of publicity, guidelines, or APP along with labeling.

• Journal of the Korean Society for Heat Treatment
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• v.24 no.6
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• pp.318-326
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• 2011

This study has been performed to investigate the effect of Al addition on High Temperature Gas Nitriding (HTGN) in 13%Cr-0.16%C stainless steel with different Al contents of 0.54%, 1.76% and 2.36%, respectively. HTGN treatment was carried out at $1100^{\circ}C$ for 1 hr, 5 hrs and 10 hrs. Nitrogen-permeated surface layers showed round type carbides of $Cr_{23}C_6$ and needle type nitrides of AlN in the matrix of martensite, representing 600~700 Hv. And the thickness of the surface layer increased with increasing Al content and HTGN treatment time. The inner region that was not permeated nitrogen showed chromium carbides in the mixed phase of martensite and ferrite for the 0.53% Al alloyed steel, however chromium carbides in the matrix of ferrite single phase were shown for the steels with the addition of 1.76%Al and 2.36%Al, representing the hardness of ~200 Hv. During nitrogen permeation from surface to the interior, substitutional elements of Cr, Al and Si moved toward the surface and interstitial element of carbon also moved from interior to the surface. This movement of alloying elements leads high concentration of these elements at the outmost surface, subsequently the lowest peak of substitutional elements were shown in the vicinity of near surface. After showing the lowest peak, the high concentration region of Al and C were formed due to the continuous movement of Al toward the surface. The long discontinuous precipitates of $Cr_{23}C_6$ and AlN were formed along the outmost surface owing to the high concentration of these alloying elements.

• The Journal of Korean Association of Computer Education
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• v.6 no.3
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• pp.151-162
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• 2003

In 21 century information age, teachers have to help students' learning activities can be more self- directed learning. The web with diverse audio-visual materials and a great deal of interactions among contents shows lots of possibilities as one of the methods to provide self-directed learning environment for students. It allows learning environment for students to study more self-directed way by following individual learning styles, need, ability, etc. Although the best instructional method is personal field experience in the view of the characteristic of Practical Arts education. a web courseware can be a great substitutional method for improving learning effectiveness in relation to cost, safety, time limit for direct personal field experience. Therefore, the purpose of this study is to develop a web courseware for the unit 'Raising Animals' in Elementary school 6th grade Practical Art which is very difficult unit for teachers to provide direct experience environment for students. The researchers also applied the web courseware in 6th grade classrooms and described the results briefly. However, the researchers did not intend to conduct a full field implementation of the program to evaluate the program. That will be conducted in a following.

• Hwankyungkyoyuk
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• v.10 no.2
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• pp.51-62
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• 1997

The objective of this study was to review the meaning and problems of Scientific Knowledge and Ethical Value in Environmental Education. The ultimate goal of environmental education is shaping proenvironmental human behavior. The factors of human behavioral decision making are ideology, value, attitude and behavioral intentions. Ideology is a kind of belief system used by social groups to interpret their social world. The main elements of belief system are knowledge and value. The traditional thinking in education has been that we can change behavior by making human beings more knowledgeable and more valuable. In environmental education, the aim of scientific inquiry is to analysis cause-effect relation of human beings behavior and environmental phenomenon, and ethical education is to change the mind of human beings from zero-sum to positive-sum about the relations between human beings and natural environments. But, there are many problems of knowledge education and value education in environmental education. For example scientific knowledge without ethical value is dangerous to environment protection, and ethical value without scientific knowledge is vague. Therefore, we must recognize that the relationship of ethical value and scientific knowledge is not substitutional but complementary. The teaching-learning methods which can integrate knowledge and value in environmental education are rational decision making model. For this model, we can construct teaching contents with inquiry materials. To earn the benefits of specialization among several subjects in environmental education, social studies can focus on social science knowledge and decision making, science education can focus on pure natural science knowledge and scientific investigation, moral education can focus on problems of ethical value system, home economics can focus on practical action and environmental education(Environments in middle school, Ecology and Environments in high school) can integrate social-national science knowledge and ethical value in broad perspective about human beings and ecosystem. That is the method to protect from law of diminishing marginal utility of learning in environmental education.