• 분석과학
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• 제16권5호
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• pp.339-348
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• 2003

본 연구에서는 동시 형광분광법과 GC/FID법을 이용하여 폐윤활유 시료 중의 PAHs를 acetonitrile 용매로 추출하여 정량분석 하였다. 동시 형광분광법을 이용하여 7종의 PAHs, 즉 acenaphthene (Ace), anthracene (Anth), benzo(a)pyrene (BaP), chrysene (Chry), phenanthrene (Phen), fluoranthrene (Fl) 및 perlyrene (Per)을 분석하였다. 이들 성분의 검정선은 모두 0.4~166 ppb(상관계수; 0.9985~0.9999)의 범위에서 직선을 보였다. 다른 8종의 PAHs를 GC법으로 분석하기 위한 검량선은 10.0 ppm 표준용액을 사용하였고, split ratio를 10에서부터 100까지 변화시킬 때에 발생되는 peak 면적을 이용하여 작성하였다. 검출감도는 동시 형광분광법이 GC법보다 적어도 100배 이상 우수하였다. 폐윤활유 시료 중의 총 PAHs 함량은 LNG(버스)와 LPG(택시)의 폐윤활유에서 각각 5.5 ng/g과 10.5 ng/g의 수준으로 검출되었으며, 가솔린을 사용하는 일반승용차, 경유를 사용하는 승합차 및 트레일러의 폐윤활에서 각각 92.2 ng/g, 92.6 ng/g 및 130.3 ng/g 등이 측정되어 경유를 사용하는 대형트레일러에서 가장 많은 양이 발생됨을 알 수 있었다.

• 한국초지조사료학회지
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• 제39권3호
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• pp.178-184
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• 2019

The objective of this study was to evaluate the dry matter yield of (DMY) of Italian ryegrass (IRG) forage crop based on two seeding date (September 25 and October 2) in 2017 and 2018, and evaluation of the potential reason of DMY reduction in IRG cultivars grown at Chuncheon, South Korea. Three cultivars of IRG including Kowinearly, Kowinmaster and Hwasan 104 were used in this experiment. The experimental field was designed as a split-split-plot arrangement. The cultivars were harvested on April 26 before the heading stage of both years. In this study, no significant effect (p>0.05) of seeding date has been found on the DMY, whereas the cultivars and year showed a significant effect on the DMY (p<0.05). Except September 25 of 2017, Hwasan 104 indicated significantly lower (p<0.05) DMY than Kowinearly and Kowinmaster in all seeding periods. Though no significant difference (p>0.05) was observed for the DMY between the two seeding dates in 2018, but the DMY was significantly lower (p<0.05) than that of 2017. Lower crude protein (CP) content of Kowinearly was observed on the seeding date of October 2 of 2017, and also in both seeding dates on 2018 (p<0.05). No significant difference (p>0.05) was observed in acid detergent fiber (ADF) between the cultivars on both seeding dates and years. Similarly, no significant difference (p>0.05) was found in neutral detergent fiber (NDF) between the cultivars in 2017. However, Kowinearly showed higher NDF content as compared to Kowinmaster and Hwasan 104 on both seeding dates and years. The seeding date has no significant difference (p>0.05). Thus, considering the extent of DMY in both years, the mean minimum temperature during winter season could be the limiting factor for the DMY of IRG cultivars. However, based on this study, the seeding dates of September 25 and October 2 have no potential effect on the DMY. Thus, on the basis of the current DMY and forge quality parameters, the cultivation Kowinmaster is recommended in Chuncheon.

• 재무관리연구
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• 제24권1호
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• pp.1-27
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• 2007

본 연구에서는 1998년부터 2002년 동안 주식분할을 실시한 과거 거래소 상장기업을 대상으로 장기성과를 분석하였다. 장기성과는 Event-time 포트폴리오 접근방식으로 측정되어지는 BHAR과 CAAR을 이용하였고 또한 Calendar-time 포트폴리오 접근방식으로 1요인 CAPM 모형과 3요인 모형을 이용하였다. 분석결과 주식분할의 공시월 부근에서 유의적인 양(+)의 초과수익률을 발견할 수 있었다. 이러한 결과는 기존 국내 연구들에서 밝혀진 바와 같이 주식분할의 공시효과가 존재한다는 것을 재확인 한 것이다. 하지만 이후 기간별 BHAR과 CAAR 모두 유의적인 음(-)의 초과수익률이 나타났으며, 이러한 결과는 Calendar-time 포트폴리오 접근방식인 1요인 CAPM 모형과 3요인 모형에서도 재확인 할 수 있었다. 분할비율에 따른 BHAR과 CAAR을 분석한 결과 분할비율이 높은 기업군도 주식분할 이후 여전히 음(-)의 초과수익률이 나타났으며 주식분할 이전 보다 이후에 영업성과가 더 악화되는 것으로 나타났다. 따라서 주식분할이 기업의 수익성이 개선된다는 신호로 보기에는 무리가 있었다. 배당성향의 증감에 따라 표본을 분류하여 장기성과를 분석한 결과에서 두 표본 간에 뚜렷한 차이를 발견할 수 없었다. 본 연구의 결과를 통하여 볼 때 주식분할은 한국 주식시장에서 단기적으로는 주가에 양(+)의 영향을 미치고 있지만 장기적으로는 주식분할이 주가에 미치는 영향은 없는 것으로 판단된다.

• 감성과학
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• 제13권1호
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• pp.251-258
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• 2010

'Naturalness'의 경우 화질 평가에 있어서 중요한 요인으로 여겨진다. 'Naturalness'는 다른 감성이 부여되는 이미지의 컨텐츠에 의존하는 중요한 요인이다. The Image Quality Circle은 한 단계에 해당하는 'ness' 단계를 두 가지로 나누었다. 두 단계 중 하나는 lightness, colourfulness, hue and contrast와 같은 지각 속성을 예측하는 단계이다. 다음 단계는 이미지의 컨텐츠에 따른 SSE를 찾는 단계이다. 이 연구에서 이미지들은 TV장르로 분류해 놓았다. 각각의 이미지들은 lightness, colourfulness, hue and contrast를 단계별로 변형시켰다. 각 변형된 이미지의 화질 점수와 SSE의 점수를 실험 참가자들에게 물었다. 정성적 항목에 7 점 단계의 정량적 평가를 실시하였다. 각 장르에 따른 세 가지 SSE를 변수로 이용하여 화질 평가 모델을 수립하였다. 생생함 (vividness)은 모든 장르에 공통으로 존재하는 SSE이고 나머지 SSE들은 모두 모델에서 독립변수로 취급하였다. 그 후 색 속성을 이용하여 각 장르에 따른 생생함을 예측하는 모델을 수립하였다. 생생함은 각 장르에 따라 의미가 다르며 화질 평가와 자연스러움(Naturalness)룰 연결하는 중요한 요인이다. 각 장르마다 생생함이 다른 의미로 여겨지기 때문에 각 장르에 생생함을 최적으로 표현하는 색 속성 또한 장르마다 다를 것이다.

• Animal Bioscience
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• 제34권6호
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• pp.1078-1087
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• 2021

Objective: Skeletal muscle satellite cells (SMSCs) are significant for the growth, regeneration, and maintenance of skeletal muscle after birth. However, currently, few studies have been performed on the isolation, culture and inducing differentiation of goose muscle satellite cells. Previous studies have shown that C1q and tumor necrosis factor-related protein 3 (CTRP3) participated in the process of muscle growth and development, but its role in the goose skeletal muscle development is not yet clear. This study aimed to isolate, culture, and identify the goose SMSCs in vitro. Additionally, to explore the function of CTRP3 in goose SMSCs. Methods: Goose SMSCs were isolated using 0.25% trypsin from leg muscle (LM) of 15 to 20 day fertilized goose eggs. Cell differentiation was induced by transferring the cells to differentiation medium with 2% horse serum and 1% penicillin streptomycin. Immunofluorescence staining of Desmin and Pax7 was used to identify goose SMSCs. Quantitative realtime polymerase chain reaction and western blot were applied to explore developmental expression profile of CTRP3 in LM and the regulation of CTRP3 on myosin heavy chains (MyHC), myogenin (MyoG) expression and Notch signaling pathway related genes expression. Results: The goose SMSCs were successfully isolated and cultured. The expression of Pax7 and Desmin were observed in the isolated cells. The expression of CTRP3 decreased significantly during leg muscle development. Overexpression of CTRP3 could enhance the expression of two myogenic differentiation marker genes, MyHC and MyoG. But knockdown of CTRP3 suppressed their expression. Furthermore, CTRP3 could repress the mRNA level of Notch signaling pathway-related genes, notch receptor 1, notch receptor 2 and hairy/enhancer-of-split related with YRPW motif 1, which previously showed a negative regulation in myoblast differentiation. Conclusion: These findings provide a useful cell model for the future research on goose muscle development and suggest that CTRP3 may play an essential role in skeletal muscle growth of goose.

• 한국토양비료학회지
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• 제46권5호
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• pp.399-407
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• 2013

Organic grape was generally produced in rainshield or plastic greenhouse culture while most of fruits were produced in open field. But little attention has been given to soil properties with different culture facilities in organic grape cultivation. This study was conducted to investigate soil physico-chemical properties of organic grapes farms with different culture facilities and soil management practices. Organic fertilizer was main resource to manage soil at organic grapes farms. Organic grapes farms were applied with total amount of organic fertilizer at one time, either at basal or additional fertilization, whereas conventional grapes farms applied with split fertilization. Bulk density and penetration resistance of soil were lower at both rainshield and green manure-applied plastic greenhouse cultures than those at clean plastic greenhouse culture. Especially, in plastic greenhouse, sod culture with natural weed after green manure application was more effective than general sod culture in improving physical properties of the rhizosphere. The contents of organic matter, available phosphate and exchangeable potassium tended to increase in the soils applied with green manure, and the difference of soil chemical properties were significant between rainshield and plastic greenhouse cultures. The optimum soil management was required in plastic greenhouse because pH, available phosphate and exchangeable cations reached over optimum range. Consequently, the ground cover management is the key factor to affect the chemical properties as well as soil physical properties extensively in plastic greenhouse. It is found that sod culture with natural weed after green manure application resulted in enhancement of utilization efficiency of nitrogen, phosphoric acid and potassium in soil in comparison with general sod culture.

• 대한치과의사협회지
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• 제54권5호
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• pp.365-373
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• 2016

Purpose: Cemental tear is a specific type of root surface fracture characterized by a complete separation of a cemental fragment along the cementodentinal junction or a partial split within the cementum along an incremental line. It is suggested to be a factor for periodontal or periapical tissue destruction. The aim of this study is to present a diagnosis and treatment of cemental tear associated with periapical lesion with root canal treatment and regenerative periodontal surgery. Treatments: A 60-year-old male who had a history of sports trauma on the mandibular right central incisor about 10 years ago presented with apical cemental tear. Clinical examination showed a slightly dark yellowish discoloration and sinus tract that was located on the apical labial mucosa. The mobility and percussion were also assessed on the diseased tooth and recorded as $Miller^{\circ}{\phi}s$ Class II and tenderness to percussion. The probing depth was within the normal limit (<3 mm). Radiographic examination revealed a radiolucent lesion at the apical area and extended to distal aspect of the tooth along the fragment of cemental tear. After root canal treatment, periapical surgery was performed. The bony defect was exposed and then the detached root fragment was removed. Apical root resection and retrograde filling with Mineral Trioxide Aggregate (MTA) were accomplished and the bony defect was filled with deproteinized bovine bone mineral (DBBM) and covered with biodegradable collagen membrane. Results: After 9-month follow-up, healing of the mandibular right central incisor was uneventful and no swelling, purulence or pain was revealed in the associated area. Probing pocket depth was favorably stable, and the tooth mobility was decreased to the Miller's Class I. Conclusions: Apical cemental tear associated periapical lesion could be successfully treated with removal of the detached cementum in combination with apical surgery and GTR procedure.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제33권2호
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• pp.137-143
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• 2011

Purpose: Orthognathic surgery is required in patients with severe skeletal disharmony and facial asymmetry, which results in functional and esthetic improvement. Recently, bimaxillary surgery has become generalized. Establishment of the occlusal plane among several other factors included in the surgery plan is a major consideration for the diagnosis and treatment plan and it is also an important factor for postoperative stability. Methods: In this study, we assessed postoperative stability of occlusal plane, B-point, and pogonion point on 20 patients who underwent two-jaw surgery in the Chosun Dental Hospital from 2000 to 2007. Preoperative and postoperative states and at least a one year postoperative follow-up were compared. Results: The postsurgical relapse volume of the occlusal plane to the SN plane and the FH plane was $-0.26{\pm}2.8^{\circ}$ and $-0.44{\pm}3.29^{\circ}$, respectively and after two-jaw surgery, the stability of occlusal plane was maintained. The horizontal relapse degree was $0.85{\pm}0.46$ mm and $0.76{\pm}0.48$ mm, respectively, and the vertical relapse degree was $1.16{\pm}0.36$ mm and $1.13{\pm}0.71$ mm of the B point and the Pogonion point at the time after minimal 1 year. Conclusion: The vertical relapse amount was shown to be slightly larger than the horizontal relapse amount.

• 한국항공우주학회지
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• 제32권4호
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• pp.61-66
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• 2004

본 논문은 액체 로켓 엔진 연소기에 사용하는 분사기의 연소 안정성 평가를 위한 모델 시험 방법을 서술하고자 한다. 액체 로켓 엔진 연소실에서 발생하는 연소 조건을 모사하기 위해서 로켓 엔진 연소기에 적용되는 실물 크기 분사기를 이용하여, 기체상태의 산소와 메탄과 프로판의 혼합기체를 모의 추진제로 사용한 모델 연소 시험을 수행하였다. 본 모델 시험의 주요 가정은 추진제의 혼합 과정이 실제 엔진 연소기에서 발생하는 연소 불안정에 가장 큰 영향을 미치는 인자로 간주하는 것이다. 본 시험에서는 단일 F-OO-F 형태의 충돌형 분사기가 한쪽 끝이 열린 원통형 모델 연소기와 더불어 사용되었다. 기상 연소 조건에서 발생하는 동압 특성은 운전 조건에 따라 상대적인 음향 감쇠 특성을 보인다. 이러한 시험 결과를 통해 구해질 수 있는 운전 조건에 따른 음향 감쇠 특성 지도를 이용하여 여러 후보 분사기 중에 가장 안정적인 분사기를 선택할 수 있게 된다.

• 한국조경학회지
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• 제33권5호통권112호
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• pp.31-42
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• 2005

This study has been conducted in order to better understand a concrete and evidential disagreement that resulted from a conflict caused by the exploitation of folk village for tourism purposes. The purpose of this study was to analyze more realistically the phenomenon of the disagreement that originated from sightseeing in the hahoe folk villages by focusing on the problem between the ive groups as a potential and continual impediment to tourism. Two groups, residents and tourists, were compared in order to determine the underlying factors of the disagreement regarding exploitation of folk villages for tourism The two groups were clearly split: inhabitants of the village considered such exploitation negative, while tourists accepted it as positive. The two groups showed different understandings of the topic residents were in favor of the preservation of the physical resources, but against exposure of their private lives to the public, while tourists strongly respected the preservation of the resources of the village. A comparison of the common phenomena of disagreement between the two groups was performed, Variables that showed different responses between the two groups were loss of privacy of individual houses, verbal aggression and physical conflicts between the groups, and lack of administration. In most of the cases of disagreement, residents considered the disagreement phenomena to be more serious than tourists did except in one case: tourists placed a greater importance on the ugly view of the street market. Finally, in order to analyze the factors that impacted the level of the disagreement, a multiple regression analysis was conducted. Disagreement factors affecting tourists were verbal aggression between the groups, complaints about lodging and dining facilities, complaints about tourist facilities, and negligence of the administration in responding to requests. Among these, the most influential factor was verbal aggression between the groups. In fact, individual feelings between tourists and residents proved to be the biggest influence on the level of disagreement.