• Journal of the Korean earth science society
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• v.42 no.6
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• pp.677-687
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• 2021

In this study, we analyzed diatoms from core RS15-GC41 collected in Iselin Bank, Ross Sea. A total of 24 genera and 35 species of diatoms are identified, and the having valve abundance of diatoms varies from 0.2 to 28.6×10⁶/g. Four diatom assemblage zones are established by the vertical distribution of diatoms, and changed with a cycle of 100 kyrs. RS15-GC41 were deposited over the last 400 kyrs (corresponding to Marine Isotope Stages 1-11). The open-water species Fragilariopsis kerguelensis, Rhizosolenia styliformis, and Thalassionema nitzschioides abundantly occurred in interglacial periods. Whereas, Actinocyclus actinochilus abundantly dominant during the glacial periods. The distribution of these diatoms indicated, it can be seen that the sea-ice extent was larger and lasted longer during MIS 7, 9, and 11 than that of MIS 1, 3, and 5. Moreover, Paralia sulcata was abundantly predominant in MIS 7, 9, and 11; this finding suggests likely indicating that P. sulcata was transported from the coastal/inner shelf area to the study site, during accumulated in the sediments, reworked with the influx of ice-rafted debris by the currents

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.6
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• pp.82-92
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• 2022

This study aims to investigate the effect of total electrochemical cell resistance (TECR) on electrochemical impedance (EI) measurements of reinforced concrete (RC) by electrochemical impedance spectroscopy (EIS) using a three-electrode system. A series of experimental study is performed to measure electrochemical behavior of a steel bar embedded in a concrete cube specimen, with a side length of 200 mm, in various experimental conditions. Main variables include concrete dry conditions, coupling resistance between sensing electrodes and concrete surface, and area of the counter electrode. It is demonstrated that EI values remains stable when the compliant voltage of a measuring device is sufficiently great compared to the potential drop caused by TECR of concrete specimens. It is confirmed that the effect of the coupling resistance of TECR is far more influential than other two factors (concrete dry conditions and area of the counter electrode). The results in this study can be used as a fundamental basis for development of a surface-mount sensor for corrosion monitoring of reinforced concrete structures exposed to wet-and-dry cycles under marine environment.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.34 no.1
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• pp.1-7
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• 2024

β-Ga₂O₃ is a material with a wide band gap of ~4.8 eV and a high breakdown-voltage of 8 MV/cm, and is attracting much attention in the field of power device applications. In addition, compared to representative WBG semiconductor materials such as SiC, GaN and Diamond, it has the advantage of enabling single crystal growth with high growth rate and low manufacturing cost [1-4]. In this study, we succeeded in growing a 10 mm thick β-Ga₂O₃ single crystal doped with 0.3 mol% SnO₂ through the EFG (Edge-defined Film-fed Growth) method using multi-slit structure. The growth direction and growth plane were set to [010]/(010), respectively, and the growth speed was about 12 mm/h. The grown β-Ga₂O₃ single crystal was cut into various crystal planes (010, 001, 100, ${\bar{2}}01$) and surface processed. The processed samples were compared for characteristics according to crystal plane through analysis such as XRD, UV/VIS/NIR/Spec., Mercury Probe, AFM and Etching. This research is expected to contribute to the development of power semiconductor technology in high-voltage and high-temperature applications, and selecting a substrate with better characteristics will play an important role in improving device performance and reliability.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.2
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• pp.215-220
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• 2011

In order to estimate the inorganic nutrient content in cucumber leaves at respective growth stages under greenhouse conditions, we investigated five cucumber farms practicing a forcing cultivation system with nine-month growth period and another five cucumber farms practicing a semiforcing cultivation system with six-month growth period. The cucumber yield in forcing and semiforcing cultivation systems amounted to 14.8 ton $10a^{-1}$ and 10.7 ton $10a^{-1}$, respectively. Soils between two different cultivation systems showed no significant differences in pH, organic matter contents and exchangeable cation contents during early growth stage, whereas EC, $NO_3$-N and available $P_2O_5$ contents were higher in soils of semiforcing cultivation systems. Suitable soil temperature was well provided by forcing cultivation. The highest NPK contents in leaves were observed in 60~80 days after planting for forcing systems and in 100 days after planting for semiforcing systems. Thereby forcing cultivation systems showed somewhat higher NPK contents. Ca and Mg contents in cucumber leaves did not significantly change during the growth period in forcing systems, while semiforcing systems showed the highest contents of Ca and Mg in 80~100 days after planting. Fe, Mn and Zn contents in leaves also did not significantly change during the growth period, whereas Mn contents were slightly higher in forcing systems due to lower soil pH. B contents in leaves were higher in semiforcing systems because of higher available B contents in soil.

• Childhood Kidney Diseases
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• v.4 no.1
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• pp.48-56
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• 2000

Purpose: Alport SD., the most common herectitary rephriris, is a renal disease with rapid progression. Deafness, ocular abnormalities and a specific EM finding may be associated in addition to a family history. We have aralyged retrospectively. Methods: We observed 12 children with Alport syndrome who were diagnosed at Dept. of pediatrics in Kyunghee Univ., College of Medicine, from Apr. 1991 until Jun. 1999. We used four criteria for diagnosis: renal disease, family history, deafness or eye abnormalities, and a specific finding in electron microscopy Results: 2 of 12 patients had all features of the four diagnostic criteria. We could not trace an exact family history in 3 patients, and 6 patients did not exhibit deafness or eye abnormality. One could not have renal biopsy because offer chronic renal failure. Other three criteria were observed in her. The ratio of male to female observed was 1:2 respectively and the mean age of initial renal symptom was 5.6 years. 9 of 12 patients had a family history of renal disease. In the audiogram and ocular examination for 11 of 12 cases, sensorineural hearing loss was observed in 6 and ocular abnormality in 2 cases. In electron microscopic finding, irregular thickness of the capillary basement membranes with lamination of lamina densa and foot process obliteration was noted in 9 of 11 and thin basement membrane with splitting and foot process obliteration was noted in the other 2. The mean period of follow-up was 3 6/12 years. And one patient developed the chronic renal failure until now and had kidney transplantation. Conclusion: For the diagnosis of Alport syndrome, the following four diagnostic criteria are very important : renal disease, family history, deafness or eye abnormalities, and a specific finding on electron microscopy. We expect that more patients can be detected through the analysis of these characteristics.

• Journal of Korean Society of Forest Science
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• v.50 no.1
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• pp.56-71
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• 1980

To study the changes of vegetational composition of each plant successional stage of Pinus densiflora forest caused by pine gall midge damage, Thecodiplosis japonensis, located in Kyonggi-do area, the middle part of Korea, four districts, Anseong, Yongin, Gwangju, and Gapyeong, were selected according to the length of insect damage duration. The forest in the Anseong district was the noninfested one selected as the check. And forests in Yongin, Gwangju, and Gapyeong were the recent]y damaged, severely damaged, and damage prolonged ones in sequence. It was considered that this order could be in concord with the gradual transition of plant successional stage. In view of temperature, precipitation and soil factors, these four districts were sited within the same environment. Four survey plots were selected from each district and the distance between them was 3~4 km. Then again four subplots were set within a plot. Through needle accumulation after insect infestation, light intensity, soil moisture content, and the amount of soil organic matter were increased and these conditions could create a favorable environment enabling the new species invasion and their growth. These were naturally closely related with the increase in quantity of Pinus densiflora defoliation. After considerable time lapse, the quantities of above mentioned factors decreased with the development of the new substitute tree species. It was found that Quercus mongolica was an excellently substitute tree species come first in this studied area. Species diversity increased to a degree at the early stage of the duration of pine gall midge damage and decreased thereafter. As the same manner, similarity index value between plots in the same district decreased to a degree and increased thereafter. This was linked admittedly with the increase and decrease of tree species and evenness. Synthesizing above mentioned results, the process of plant succession studied quantitatively by changes of relative density and relative importance value, it can be concluded that Pinus densiflora forest gives way to Genus Quercus forest in which Genus Lespedeza and Genus Rhododendron species become as subdominance species after removal of the Pinus densiflora trees damaged by pine gall midge.

• Journal of Nutrition and Health
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• v.51 no.1
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• pp.87-102
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• 2018

Purpose: The purpose of this study was to develop a valid instrument for measuring the dietary quality and behaviors of Korean elderly. Methods: The development of the Nutrition Quotient for Elderly (NQ-E) was conducted in three steps: item generation, item reduction, and validation. The 41 items of the NQ-E checklist were derived from a systematic literature review, expert in-depth interviews, statistical analyses of the fifth Korean National Health and Nutrition Examination Survey data, and national nutrition policies and recommendations. Pearson's correlation was used to determine the level of agreement between the questionnaires and nutrient intake level, and 24 items were selected for a nationwide survey. A total of 1,000 nationwide elderly subjects completed the checklist questionnaire. The construct validity of the NQ-E was assessed using confirmatory factor analysis, LISREL. Results: The nineteen checklist items were used as final items for NQ-E. Checklist items were composed of four-factors: food behavior (6 items), balance (4 items), diversity (6 items), and moderation (3 items). The standardized path coefficients were used as the weights of the items. The NQ-E and four-factor scores were calculated according to the obtained weights of the questionnaire items. Conclusion: NQ-E would be a useful tool for assessing the food behavior and dietary quality of the elderly.

• Korean Journal of Heritage: History & Science
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• v.46 no.4
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• pp.48-63
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• 2013

The results of the study on the space planning and landscape design of Unjoru(雲鳥樓) through the 'Jeolla Gurye Omidong Gado(全羅求禮五美洞家圖)' drawn using GyeHwa(界畵) technique are as follows. First, 'Omidong Gado' is believed to date back to the period when Unjoru(1776~1783) was established for the following reasons: (1) The founder, Yoo-IJu(柳爾?), sent the drawing for the house while he was serving as the governor of YongCheon county(龍川府史). (2) It shows the typical dwelling houses' space division and its location is in a good spot with mountain in the back and water in front(背山臨水) and there is every indication of scheme drawing. (3) Front gate was changed and remodeled to a lofty gate in 1804. Second, Nogodan & Hyeongjebong of Jiri Mountain sit at the back of Unjoru, and faces Obong mountain and Gyejok mountain. In addition, the Dongbang stream flowing to the east well illustrates the Pungsu theory of mountain in the back and water in the front. Third, the house is structured in the shape resembling the character 品, divided into 5 areas by hierarchical order in the cross line from all directions. The site, which includes the outdoor yard and the back garden, consists of 5 blocks, 6 yards and 2 gardens. Fourth, the outdoor yard with aesthetical value and anti-fire function, is an ecological garden influenced by Confucianism and Taoism with a pond (BangJiWonDo Type, 方池圓島形) at the center. Fifth, the Sarang yard(舍廊庭) is decorated with terrace garden and flower garden, and the landscaping components such as oddly shaped stone, crane, plum, pine tree, tamarisk tree and flowering plants were used to depict the ideal fairy land and centrally placed tree for metaphysical symbolism. The upper floor of Sarangchae commands distant and medium range view, as well as upwards and downwards. The natural landscape intrudes inside, and at the same time, connects with the outside. Sixth, pine forest over the northern wall and the intentionally developed low hill are one of the traditional landscaping techniques that promotes pleasant residential environment as well as the aesthetics of balanced fullness.

• The korean journal of orthodontics
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• v.37 no.3 s.122
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• pp.171-181
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• 2007

Objective: The present study was aimed at an analytical formulation of the micro-implant related torque as a function of implant size, i.e. the diameter and length, screw size, and the bony resistance at the implant to bone interface. Methods: The resistance at the implant to cancellous bone interface $(S_{can})$ was assumed to be in the range of 1.0-2.5 MPa. Micro-implant model of Absoanchor (Dentos Inc. Daegu, Korea) was used in the course of the analysis. Results: The results showed that the torque was a strong function of diameter, length, and the screw height. As the diameter increased and as the screw size decreased, the torque index decreased. However the strength index was a different function of the implant and bone factors. The whole Absoanchor implant models were within the safe region when the resistance at the implant/cancellous bone $(=S_{can})$ was 1.0 or less. Conclusion: For bone with $S_{can}$ of 1.5 MPa, the cervical diameter should be greater than 1.5 mm if micro-implant models of 12 mm long are to be placed. For $S_{can}$ of 2.0 MPa, micro-implant models of larger cervical diameter than 1.5 mm were found to be safe only if the endosseous length was less than 8 mm.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.31 no.1
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• pp.59-70
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• 2013

This study was to suggest cultural landscape preservation, value creation, as well as utilization plan to help landscape development of Hahoe village by identify the existence of Okyeonsipyeong(玉淵十詠) natural features, which were set around Buyongdae(芙蓉臺) in Hahoe Village by Seoae(西崖) Ryu, Seongryong(柳成龍), and understanding their characteristics and meanings of natural features and meanings. Based on the writings of "Okyeonseodanggi" and "Okyeonsipyeong", the major results of this study are as belows. 'Okyeon(玉淵)' letters carved on the rocks, also known as the name of pavilion in Okyeonjeongsa(玉淵精舍), is the center of Okyeonsipyeong that symbolizes the enlightenment of clean noble man, as well as the symbolic locational expression of studying room. One of Okyeonsipyeong, 'Wansimjae', is assumed to be the name from the combination of two Buddhist names, 'Wanjeok(玩寂)' and 'Seshim(洗心)', 'Dangho(堂號)', lined on both sides with Wonlakjae, the residence of Seoae, as the center. Wansimjae is after all the natural feature indicating the overall Okyeonjeongsa as the core of Okyeonsipyeong with west edge Gyeomamjeongsa(謙巖精舍). Among ten Okyeonsipyeong natural features, Wansimjae(玩心齋), Ganjukmun(看竹門), Gyeomamsa(謙菴舍), Dalgwandae(達觀臺), Ssangsongae(雙松厓), and Dohwacheon (桃花遷) are on the right side of the stairway from Okyeonjeongsa to Gyeomamjeongsa, while Chuwoldam(秋月潭), Neungpadae(凌波臺), Gyeseonam(繫船巖), and Jijuam(砥柱巖) are on the road to the cliff under river cliff in Buyongdae as well as to the dock, and all are located within 500m radius close and diameter area. As the results of lexeme and context analyses of Okyeonsipyeong poet, they are mainly about Confucian teachings symbolizing the constancy of the classical scholar including ego becoming one with the nature and back to the nature, unworldliness and farsighted view, transcendence and seclusion, as well as integrity spirit. In Dohwacheon and Gyeomamsa poets, there is Tao characteristics and brotherhood that pursue fairylands such as Mooreungdowon(武陵桃源). To create tourism brand and landscape of Okyeonsipyeong, it is necessary to prepare storytelling plans including the letters carved on the rocks introduction in Buyongdae area, and also synopsis of the Silgyeongsusang musical, 'Buyongjiae(芙蓉之愛)' that is related to 10 natural features. In addition, the related plans of the experience road from Gyeseonam, which is the boat stop in Buyongdae, to Ganjukmun of Okyeonjeongsa, and again to viewing routes on the stairways to Gyeomamjeongsa using boats are necessary. For preliminary preservation and maintenance plans, the safety of the stairway from Okyeonjeongsa to Gyeomamjeongsa should be secured, the rock inscription should be preserved, landscape interpretation plates should be installed, trees and shrubs around Dohwacheon rock inscription should be removed, Dalgwandae letters carved on the rocks should be restored, and the bamboo forest outside Ganjukmun as well as Prunus persica plantation around Dohwacheon should be pointed out.