• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.11
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• pp.1491-1496
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• 2008

Twenty natural plants from Jeju were extracted by pressurized organic solvent (100% methanol, $40^{\circ}C$, 13.6 MPa, 10 min). Extraction yield, total phenolic content (TPC) and integral antioxidant capacity were measured, and each component was identified by GC/MS. Extraction yields were high as 21.8%, 21.5, 21.1, 20.7 and 20.1% in Rhus javanica, Euscaphis japonica, Alnus firma, Sapium japonicum and Sorbus alnifolia, respectively. The extracts containing high TPC (mg GAE/g of dry sample) were obtained from Malus sieboldii (68.3), Sapium japonicum (57.6), Pyrrosia lingua (56.6) and Euscaphis japonica (55.1). Integral antioxidant capacities of water-soluble substances were 598, 394, 293 and $270\;{\mu}mol$ ascorbic acid equivalent/g in Geranium thunbergii, Sapium japonicum, Cornus kousa and Rhus javanica, respectively. Integral antioxidant capacities of lipidsoluble substances were 611, 314, 296 and $242\;{\mu}mol$ trolox equivalent/g in Ardisia crenata, Ostrya japonica, Geranium thunbergii and Quercus acuta, respectively. Fifteen major peaks were identified by GC/MS from the extract of pressurized organic solvent from Sapium japonicum. Two polyphenols (gallic acid (retention time (RT) 19.7 min)) and quercetin (33.5 min)), ascorbic acid (RT 35.3 min), and several fatty acids (retention time 18.6, 21.0, 21.8, 21.9 and 23.6 min) were identified, and gallic acid was the major polyphenol component due to high peak area.

• The Korean Journal of Food And Nutrition
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• v.36 no.5
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• pp.379-386
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• 2023

The objective of this study was to investigate the distribution of functional compounds in perilla leaves of various genetic resources and their antioxidant activities. A comprehensive analysis of functional compounds was conducted for 90 genetic resources, focusing on total polyphenol content (TPC), total flavonoid content (TFC), individual phenolic content (IPC), and lutein. Their antioxidant activities were then analyzed based on their radical scavenging capacity using ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and DPPH (2,2-diphenyl-1-picrylhydrazyl). The TPC content exhibited a range of 13.19 to 35.85 mg gallic acid equivalent/g, whereas the TFC content varied from 11.74 to 46.51 mg catechin equivalent/g. Total IPC was detected in a range of 6,310.98 to 40,491.82 ㎍/g. Lutein was detected at levels between 70.97 and 597.97 ㎍/g. ABTS and DPPH radical scavenging activities of perilla leaves ranged from 30.39 to 58.58 mg trolox equivalent (TE)/g and from 7.74 to 46.56 mg TE/g, respectively. Furthermore, correlation analysis demonstrated that rosmarinic acid, a phenolic acid, exhibited a significantly positive correlation with antioxidant activity. These findings suggest that various genetic resource of perilla leaves could effectively mediate antioxidant capacity. Results of this study provide valuable information for use of perilla leaves in Korea as functional food materials.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.2
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• pp.423-433
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• 1999

Purpose : To assess the methods for the clinical evaluation of the longitudinal bone changes after implantation of tooth ash-plaster mixture into the defect area of human jaws. Materials and methods : Tooth ash-plaster mixtures were implanted into the defects of 8 human jaws. 48 intraoral radiograms taken with copper step wedge as reference at soon, 1st, 2nd, 4th, and 6th week after implantation of mixture were used. X-ray taking was standardized by using Rinn XCP device customized directly to the individual dentition with resin bite block. The images inputted by Quick scanner were digitized and analyzed by NIH image program. Cu­equivalent values were measured at the implanted sites from the periodic digital images. Analysis was performed by the bidirectional subtraction with color enhancement and the surface plot of resliced contiguous image. The obtained results by the two methods were compared with Cu­equivalent value changes. Results : The average determination coefficient of Cu-equivalent equations was 0.9988 and the coefficient of variation of measured Cu values ranged from 0.08~0.10. The coefficient of variation of Cu-equivalent values measured at the areas of the mixture and the bone by the conversion equation ranged from 0.06 ~0.09. The analyzed results by the bidirectional subtraction with color enhancement were coincident with the changes of Cu-equivalent values. The surface plot of the resliced contiguous image showed the three dimensional view of the longitudinal bone changes on one image and also coincident with Cu-equivalent value changes after implantation. Conclusion : The bidirectional subtraction with color enhancement and the surface plot of the resliced contiguous image was very effective and reasonable to analyze clinically and qualitatively the longitudinal bone change. These methods are expected to be applicable to the non-destructive test in other fields.

• Geophysics and Geophysical Exploration
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• v.10 no.4
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• pp.361-368
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• 2007

In this paper, we suggested the relationship between resistivity of coastal groundwater and NaCl equivalent salinity for the quantitative interpretation the results of surface/borehole resistivity and electromagnetic data. 38 groundwater samples having electrical conductivity higher than about 1,000 ${\mu}S/cm$ were analyzed to derive the empirical relationship between groundwater resistivity and NaCl equivalent salinity. We used Schlumberger chart GEN-8 to convert ion concentration from hydrochemical analysis to the equivalent NaCl salinity, and the portable meter to measure the in situ electrical conductivity of groundwater samples. From the hydrochemical analysis, relationship between the groundwater resistivity $(R_w)$ and equivalent NaCl salinity (Eq_NaCl) is expressed as Eq_NaCl=$5935.3551{\times}R_w^{-1.0993}$, and relationship between the groundwater electrical conductivity (EC) and total dissolved solids (TDS) is expressed as TDS=0.721*EC. We believe these relationships are very useful to assess the seawater intrusion in western and southern coastal area.

• Advances in nano research
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• v.12 no.3
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• pp.319-336
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• 2022

Evaluating the temporal and spatial changes in the ecosystem service value (ESV) of the Sanjiangyuan Nature Reserve is important for understanding the impact of human activities on natural ecosystem and guiding ecosystem restoration and environmental pollution control. In this study, remotely sensed land-cover data and the equivalent factor method were used to analyze the spatiotemporal evolution characteristics of the ESV in Sanjiangyuan Nature Reserve from 1992 to 2015, and regression analysis was employed to determine the factors driving changes in the ESV. The results show that grassland was the main type of ecosystem in the study area, and the transformation of grassland into bare areas was the primary change in land cover. Additionally, the ESV in the study area first decreased and then increased, with an annual growth rate of 0.69%. The ESV mainly increased in the north of the Yellow River's source area, and mainly decreased in the northwest of the Yangtze River's source area. Finally, the gross output value of agriculture, urbanization rate and proportion of secondary industry were found to be the main factors driving the ESV in the study area.

• Research in Mathematical Education
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• v.16 no.2
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• pp.107-123
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• 2012

A group of twenty-nine high school student-teachers were given a set of mathematical propositions focusing on shape-to-shape transformations. Their task was to determine through hands-on manipulation and use of dynamic software that each shape be transformed into an area equivalent rectangular region. This paper reports on a classroom-based research.

• Journal of the Korean Ceramic Society
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• v.22 no.6
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• pp.53-57
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• 1985

Korean montmorillonite from Youngil district was characterized by Alkylammonium derivatives. This method was very sensitive to the basal plane spacing d and the charge in the layer charge. The result include the values of average layer charge, charge distribution, equivalent area. interlayer cationic exchange capacity (C, E, C) and total C. E. C.

• Bulletin of the Korean Chemical Society
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• v.34 no.3
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• pp.892-898
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• 2013

A field emission projection microscope was constructed to investigate the atomic and chemical-bonding structure of molecules using electron in-line holography. Fringes of carbon nanotube images were found to be interferograms equivalent to those created by the electron biprism in conventional electron microscopy. By exploiting carbon nanotubes as the filament of the electron biprism, we measured the transverse coherence length of the electron beam from tungsten field emitters. The measurements revealed that a partially coherent electron-beam was emitted from a finite area.

• Proceedings of the KIEE Conference
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• 2002.11b
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• pp.38-40
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• 2002

한국전력에서는 전력설비의 염진해 대책을 위해 전국의 영진해 오손정도를 파악하기 위하여 동, 서, 남해안 및 제주도를 중심으로 1981-1988간에 걸쳐 애자를 설치하고 매월 실측하여 전국의 염진해 오손지도를 만들고 이에 의해 내오손 설계를 하는 실정이다. 그러나 이 이후 여러 기현상의 자연현상과 중국대륙의 극심한 황사현상 빛 가속화된 산업발전에의 공업오손의 영향 등으로 오손도에 적잖게 변화를 준 것으로 보고 본 논문에서는 서남권의 오손도를 직독계를 이용하여 측정하고 이를 분석하여 그 추이를 제시하였다.

• Journal of KSNVE
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• v.10 no.5
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• pp.792-799
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• 2000

Aircraft noise in the vicinity of Kimpo international airport has damaged to large number of people who live in communities. This paper investigates noise exposed area due to aircraft flight based on prediction modeling program INM and flight path data. Especially effect on route for aircraft has been considered. Ti also examines noise impact for various flight modes, such as a thrust cutback climb method.