• 연구논문집
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• s.24
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• pp.119-128
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• 1994

A special steels have been developed for the possible applications of turbine blade in nuclear power plant. The compositions of developed alloy were selected by the reference of imported alloy. The various properties such as tensile property, impact energy, hardness, and microstructures were investigated. All the properties of optimum heat treated materials were satisfied with the present specifications of turbine blade materials in unclear power plant. Furthermore, FATT(Fracture appearance transition temperature), high temperature tensile properties, and transformation temperatures of developed alloy also have been studied.

• Korean Journal of Materials Research
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• v.21 no.5
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• pp.273-276
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• 2011

Ultraviolet (UV) light emitting diodes (LEDs) were grown on a patterned n-type GaN substrate (PNS) with 200 nm silicon-di-oxide (SiO2) nano pattern diameter to improve the light output efficiency of the diodes. Wet etched self assembled indium tin oxide (ITO) nano clusters serve as a dry etching mask for converting the SiO2 layer grown on the n-GaN template into SiO2 nano patterns by inductively coupled plasma etching. PNS is obtained by n-GaN regrowth on the SiO2 nano patterns and UV-LEDs were fabricated using PNS as a template. Two UV-LEDs, a reference LED without PNS and a 200 nm PNS UV-LEDs were fabricated. Scanning Electron microscopy (SEM), Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD), Photoluminescence (PL) and Light output intensity- Input current- Voltage (L-I-V) characteristics were used to evaluate the ITO-$SiO_2$ nanopattern surface morphology, threading dislocation propagation, PNS crystalline property, PNS optical property and UVLED device performance respectively. The light out put intensity was enhanced by 1.6times@100mA for the LED grown on PNS compared to the reference LED with out PNS.

• Proceedings of the Korean Nuclear Society Conference
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• 2004.05a
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• pp.379.1-379.1
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• 2004

• Proceedings of the Optical Society of Korea Conference
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• 2006.07a
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• pp.419-420
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• 2006

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2018.11a
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• pp.187-188
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• 2018

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.20 no.1
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• pp.29-35
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• 2015

Dissolved nutrients in seawater are recognized as an essential biogeochemical factor for detecting global environmental changes. The importance of nutrient reference material for seawater has been increased greatly for the comparison of nutrient data, measured in different time and space in global ocean by various researchers with different levels in nutrient analysis skill. In this study, we described the homogeneity and stability of nutrient reference material for seawater using natural seawater, collected at a station of Shihwa Lake, at a coastal station near Uljin (surface water), and at a station over the Ulleung Basin (surface water and 1500 m depth water) and sterilized. Based on the homogeneity data, the nutrient reference materials has similar homogeneity compared to other nutrient reference materials. During 3-13 month period, there was no unidirectional trend of increase or decrease in nutrient concentration of newly developed nutrient reference material for seawater. However, a sustained measurement is required to check stability for longer period.

• Journal of architectural history
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• v.21 no.4
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• pp.37-46
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• 2012

This study examines the construction method of lime tomb of royal tombs in the Choseon Dynasty based on reference. This was primarily published as "The Five Manners and Courtesy of the Annals of Sejong" as examples, which were followed by the influence of Koryo's culture in the beginning foundation of Choseon, were organized in the time of Sejong; and later, in the time of Sungjong, "The National Five Manners and Courtes y" was published. Such old reference explains the stone materials and construction method of the royal tomb's pit yet there were not many studies regarding the pit of royal tomb in the Choseon Dynasty. And there exists no historical research or reference study in regard to the pit of royal tomb which is formed as a lime tomb. This is believed to be impossible to excavate the royal tomb since ancestral ritual formalities are still given by the descendants and because of our country's culture of giving ancestral ritual formalities which value formalities and filial duty. However, the current excavation of Guhui Tomb, which was the early burial site, was important since it gives an opportunity to look at the shape and structure of lime tombs in the Choseon Dynasty. Thus, this study, based on the excavation of Guhui Tomb, will look into the construction method of the pit of lime tomb and will examine the structure, shape, construction method, etc. of the lime tomb which was formed after the time of Sejo in a way with reference history. This is an important data to learn the construction method of limb tomb of royal tombs in the Choseon Dynasty and is believed to have a very important value as historical materials as to understanding the structure of the pit of royal tombs in the Choseon Dynasty which yet has not been excavated.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.10
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• pp.2122-2129
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• 2002

Creep damage using a reference stress(RS) was analyzed for type 316LN stainless steel. The generalized K-R equation was reconstructed into the RS equation using a critical stress value $\sigma$. The RS equation was derived from the critical stress in failure time $t_f$ instead of material damage parameter $\omega$, which indicates the critical condition of collapse or approach to gross instability of materials during creep. For obtaining the reference stress, a series of creep tests and tensile tests were conducted with at 55$0^{\circ}C$ and $600^{\circ}C$. The stress-time data obtained from creep tests were applied to the RS equations to characterize the creep damage of type 316LN stainless steel. The value of creep constant r with stress levels was about 18 at 55$0^{\circ}C$ and 21 at $600^{\circ}C$. This value was almost similar with r = 24 in the K-R equation, which was obtained by using damage parameter $\omega$. Relationship plots of creep failure strain and life fraction $(t_f /t_r)$ were also obtained with different λ values. The RS equation was therefore more convenient than the generalized K-R equation, because the measuring process to quantify the damage parameter $\omega$ such as voids or micro cracks in crept materials was omitted. The RS method can be easily used by designers and plant operator as a creep design tool.

• Journal of Environmental Science International
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• v.28 no.11
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• pp.1033-1040
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• 2019

The National Environmental Specimen Bank (NESB) has set up a plan to develop reference materials in the facility for assuring analytical quality and validating analytical methods for its monitoring samples. Some of the crucial characteristics that reference materials must consist of are homogeneity and stability of both intra and inter-bottles. In this study, we examined the homogeneity and stability of cryogenically-milled muscle samples, from Common Carp (Cyprinus carpio) for total mercury. Homogeneity was tested using ANOVA analysis and regression analysis was used to test short-term stability. The variations of total mercury concentration did not significantly differ between the intra and the inter-bottle (F=0.8, p=0.37). Additionally, relative standard deviation of the total mercury concentration showed low values (2.28%). For the short-term stability test, total mercury variations were not statistically significant as demonstrated by the result of the regression analysis (F ratio = 3.11, p = 0.18). This suggests that the cryogenic-milling process has statistically proven the degree of homogeneity and short-term stability for samples of carp muscles in the chemical analysis for total mercury.

• The Journal of the Korea Contents Association
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• v.16 no.6
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• pp.283-292
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• 2016

This paper is intended as an investigation of 5 sentence patterns which have exerted a strong influence on the English education in Korea. The 'learning grammar', which is defined as the grammar in learning materials, was compared with 'reference grammar' derived from linguistic grammar with theoretical accuracy and validity. Although the notion of 5 sentence patterns has been assumed to be vestiges of old Japan textbooks, the classification system was originally established in 1929 by C. T. Onions. Particularly, new explanations regarding 'obligatory adjuncts' and 'marked construction' were provided in the learning materials, which could be seen as examples of the reflection of linguistic grammar theories on sentence patterns. If reference grammarbooks and the fruits of linguistic grammar research are used actively, material writers can avoid the errors of grammar description and more correct learning grammar can be taught to advanced learners.