• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 춘계학술발표대회 논문집
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• pp.121-126
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• 2011

The heat from PV modules should be removed for better electrical performance, and can be converted into useful thermal energy. A photovoltaic-thermal(PVT) module is a combination of PV module with a solar thermal collector which forms one device that converts solar radiation into electricity and heat simultaneously. In general, there are two different types of PVT module: glazed PVT module and unglazed PVT module. On the other hand, two types of the PVT module can be distinguished according to absorber on PV module rear side: the sheet-and-tube absorber PVT module and the fully wetted absorber PVT module. In this paper, the experimental performance of water type unglazed PVT with fully wetted absorber was analyzed. The electrical and thermal performance of the unglazed PVT were measured in outdoor conditions, and the results were analyzed. The experimental results showed that the thermal efficiency of the PVT module was 42% average, and its electrical efficiencies were 15.2% and 14.2% average, respectively, for the mean fluid temperature of $10-20^{\circ}C$ and $21-30^{\circ}C$. Thermal efficiency depends on solar radiation, mean fluid temperature and ambient temperature. The PVT module temperature is related to the cooling effect of the PV module by the fluid of the absorber. The results proved that the electrical efficiency was higher when the mean fluid temperature was lower.

• 대한화장품학회지
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• 제32권2호
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• pp.81-88
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• 2006

피부 각질층내의 아미노산 조성비율과 유사한 조성비로 amino acid complex을 제조하고, 제조된 amino acid complex가 피부에 미치는 영향을 알아보기 위해 세포 생존율, TIMP-1 발현 증가율, 보습 및 각질량 변화를 측정하였다. 연구 결과 amino acid complex는 독성이 없는 안전한 물질로 우수한 보습력 및 보습유지효과와 ascorbic acid와 유사한 TIMP-1 발현량 증가로 주름 예방 및 개선에 효과를 가지고 있으며, 각질량 감소 및 감소유지효과로 자극이 있는 AHA 대체 물질로의 가능성을 보였다. 따라서, amino acid complex는 다기능을 가진 노화방지 화장료 기능성분으로 유용하게 사용될 수 있음을 확인하였다.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 추계학술발표대회 논문집
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• pp.93-98
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• 2011

A photovoltaic/thermal(PVT)collector produces both thermal energy and electricity simultaneously. The heat from PV modules should be removed for better electrical performance, and can be converted into useful thermal energy. A PVT module is a combination of PV module with a solar thermal collector which forms one device that converts solar radiation into electricity and heat. In general, there are two different types of PVT module: glazed PVT module and unglazed PVT module. On the other hand, two types of the PVT module can be distinguished according to absorber on PV module rear side: the sheet-and-tube absorber PVT module and the fully wetted absorber PVT module. The absorber collector plays an important function in PVT system. It cools down the PV module, while collecting the thermal energy produced in the form of hot water. The aim of this study is to compare the electrical and thermal performance of two different PVT collectors, one with the rectangular tube and the other with fully wetted absorber PVT collectors. For this paper, the PVT collectors with two different types of thermal absorber were made, and both the thermal and electrical performance of them were measured in outdoor, and the results were compared. The experimental results were analyzed that the thermal efficiency of the fully wetted absorber PVT collector is about 8.7% higher than the sheet-and-tube absorber PVT collector, and for the electrical efficiency, the fully wetted absorber PVT collector had about 7% higher than the rectangular tube absorber.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 추계학술발표대회 논문집
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• pp.87-92
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• 2011

The heat from PV modules should be removed for better electrical performance, and can be converted into useful thermal energy. A photovoltaic-thermal(PVT)module is a combination of PV module with a solar thermal collector which forms one device that converts solar radiation into electricity and heat simultaneously. The performance of the PV/Thermal combined collector module is directly influenced by solar radiation that also has an effect on PV module temperature. It is also has believe that the energy performance of PV/T collector is related to absorber design as well as PV module temperature. The existing study has been paid to the PV/Thermal combined collector module with circle tube absorbers. The aim of this study is to analyze the experimental performance of the PV/Thermal combined collector rectangular tube absorbers according to solar radiation. The experimental result show that the average thermal and electrical efficiencies of the PVT collector were 43% and14.81% respectively. Solar radiation is one of the most influential factors to determine the energy performance of PVT collector, but from a certain level of solar radiation the PVT collector receives on, its efficiencies began to decrease.

• 대한치과보철학회지
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• 제32권4호
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• pp.565-572
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• 1994

According to the classification of dental arch form and the analysis of patterns of chewing movement, the patterns of chewing movement in each group were evaluated and compared with those of the normal group. Results were summarized as follows ; 1. Opening phase in chewing movement In the group which the maxillary second molar positionsbuccal side, the chewing patterns which have the Vertical Guide Openings in frontal plane, the Posterior Guide Openings in hjorizontal plane were observed. In the group which the maxillary premolars position lingual side, the chewing paterns which have the Protrusive Shift Openings in horizontal plane and sagittal plane were observed. 2. Closing phase in chewing movement. In each group except for the normal group, the chewing patterns which have the Concave Closure in frontal plane and in Horizontal plane were observed. In the group which the maxillary premolars position buccal side, the chewing patterns which have the Lateral Guide Closure in frontal plane and in horizontal plane, the Vertical Guide Closre in sagittal plane were observed: From the results, as the characteristics of the dental arch form have appeared in chewing movement, the close relationships were found between dental arch form and chewing movement. It is suggested that the evaluation of dental arch form is effective in the diagnosis of function of stomatognathic system.

• 대한음성학회지:말소리
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• 제4호
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• pp.20-30
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• 1982

The aim of this paper is to analyse difficulties of the pronunciation in swedish vowels encountered by Koreans learners and to seek solutions in order to correct the possible errors. In the course of the analysis the swedish and Korean vowels in question are compared with the purpose of describing differences aha similarities between these two systems. This contrastive description is largely based on the students' articulatory speech level ana the writer's auditory , judgement . The following points are discussed : 1 ) Vowel length as a distinctive feature in Swedish compared with that of Korean. 2) A special attention is paid on the Swedish vowel [w:] that is characterized by its peculiar type of lip rounding. 3) The six pairs of Swedish vowels that are phonologically contrastive but difficult for Koreans to distinguish one from the other: [y:] ~ [w:], [i:] ~ [y:], [e:] ~ [${\phi}$:], [w;] ~ [u:] [w:] ~ [$\theta$], [$\theta$] ~ [u] 4) The r-colored vowel in the case of the postvocalic /r/ that is very common in American English is not allowed in English sound sequences. The r-colored vowel in the American English pattern has to be broken up and replaced hi-segmental vowel-consonant sequences . Korean accustomed to the American pronunciation are warned in this respect. For a more distinct articulation of the postvocalic /r/ trill [r] is preferred to fricative [z]. 5) The front vowels [e, $\varepsilon, {\;}{\phi}$) become opener variants (${\ae}, {\;}:{\ae}$] before / r / or supradentals. The results of the analysis show that difficulties of the pronunciation of the target language (Swedish) are mostly due to the interference from the Learner's source language (Korean). However, the Learner sometimes tends to get interference also from the other foreign language with which he or she is already familiar when he or she finds in that language more similarity to the target language than in his or her own mother tongue. Hence this foreign language (American English) in this case functions as a second language for Koreans in Learning Swedish.

• 한국산업보건학회지
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• 제31권2호
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• pp.119-127
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• 2021

Objectives: We aimed to find the relationships between employment status and hs-CRP level among Korean wage workers using the 2016 Korean National Health and Nutrition Examination (KNHANE, revised). Methods: This study was conducted on 1,937 daytime wage workers over the age of 19 and within a normal weight range (18.5≤BMI≺25). Regular workers were defined as those granted an employment guarantee until reaching retirement age, and non-regular workers were defined as temporary, non-typical, dispatched, short-term workers and contractors. For hs-CRP, three divisions were classified as recommended by the Centers for Disease Control and Prevention (CDC) and American Heart Association (AHA) with less than 1.0 mg/L indicating low risk of cardiovascular disease, above 1.0 mg/L and below 3.0 mg/L considered moderate risk, and more than 3.0 mg/L indicating high risk. To find the relationship between work type and hs-CRP level in Korean wage workers, multinominal logistic regression analysis was performed. Results: For non-regular workers, the odds ratio of the cardiovascular moderate-risk group and cardiovascular high-risk group was statistically significant compared to regular workers. After adjusting for factors such as gender, age, subjective health status, income, education, smoking, and physical labor, the odds ratio of the cardiovascular high-risk group was statistically significant. Conclusions: In this study, the relationship between non-regular workers and high hs-CRP level was examined. Based on this, institutional strategies should be pursued to prevent and manage cardiovascular disease among non-regular workers.

• 한국방사선학회논문지
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• 제14권3호
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• pp.319-336
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• 2020

미만성 긴 병변이 있는 급성심근경색증 환자에서 장기적인 임상 결과에 대해 중첩된 약물용출스텐트와 긴 단일 약물용출스텐트라는 두 가지 중재 방법으로 시술한 환자의 관상동맥조영술 결과와 임상결과를 비교·분석하였다. 2008년 6월부터 2019년 3월까지 급성심근경색환자 (65.9±11.0세, 남성 306명)가 미만성 긴 관상동맥 병변 30 mm이상 병변에 대해서 두 그룹으로 나뉘었습니다. 그룹I (중첩 약물용출스텐트 그룹; n=140) 및 그룹II (긴 단일 약물용출스텐트 그룹; n=298). 주요심장사건의 발생률을 비교하였다[주요심장사건; 두 그룹 사이에서 12개월 동안 심장사망률, 심근경색, 표적병변 재개통술 및 스텐트 혈전증]. Everolimus-용출 스텐트는 그룹I보다 그룹II에서 더 일반적으로 사용되었고(28.1% vs. 51.8% p<0.001), 시술 전 평균 병변직경은 그룹II에서 약간 굵었고 (3.1±0.3mm vs. 3.2±0.3mm, p=0.042), ACC / AHA 병변 유형C의 유병률은 그룹I에서 더 높았다(41.7% vs. 25.4%, p<0.001). 12개월 동안 주요심장사건의 발생률은 그룹II보다 그룹I에서 더 높았고(18.5% vs. 14.4%, p=0.034), 심장 사망률 (2.1% vs. 4.4%, p=0.667), 심근경색 (5.0% vs. 2.7%, p=0.260) 및 스텐트 혈전증률 (0.7% vs. 1.7%, p=0.669)은 두 그룹 차이가 없었다. 그러나 표적병변 재개통술 비율은 그룹I에서 더 높았다(10.7% vs. 5.6%, p=0.041). 다변량 로지스틱 회귀 분석에서 당뇨병의 존재[위험률 2.383, 95 % 신뢰 구간 1.332-4.260, p=0.003]과 파클리탁셀-용출 스텐트[위험률 2.367, 95 % 신뢰 구간 1.371-4.086), p=0.002]는 12개월 주요심장사건의 독립적 예측인자였으며, 두 그룹 사이의 유병률에 큰 차이가 없었다. 미만성 병변이 있는 급성심근경색 환자에서 12개월의 추적 관찰 기간 동안 중첩 약물용출스텐트 그룹에서 표적병변 재개통술 비율이 더 높았고 당뇨병의 존재 및 파클리탁셀-용출 스텐트의 사용은 주요심장사건의 독립적인 예측인자였다.

• Journal of Chest Surgery
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• 제37권1호
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• pp.27-34
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• 2004

배경: 감염성 심내막염은 다른 심장질환에 비해 유병률과 사망률이 높고, 대부분의 임상연구가 대동맥판에 발생한 심내막염에 편중되어 있어, 승모판 심내막염에 대한 보고는 상대적으로 드문데 이에 대한 임상양상 및 수술 결과를 분석하여 보고하고자 한다. 대상 및 방법: 1995년 6월부터 2003년 5월까지 전남대학교병원에서 감염성 승모판 심내막염으로 단일 술자에 의해서 외과적 치료를 받았던 23 예을 대상으로 하였다. 2예는 인공판막 심내막염이었고 나머지 21예는 자가판막 심내막염이었다. 환자의 평균 연령은 44.8$\pm$15.7 (11∼66)세였고 연령분포에는 큰 차이가 없었다. 17예에서는 혈역학적 불안정이나 거대 우종으로 응급수술을 시행하였다. 수술 전 12예에서 울혈성 심부전, 4예에서 신부전, 2예에서 비장 및 신장경색, 2예에서 일시적 뇌손상, 1예에서 뇌농양 소견을 보였다. NYHA 기능 분류상 Grade II가 7예, Grade III가 9예, Grade IV가 6예이었다. 술 전 심초음파상 승모판 역류우세가 19예, 협착우세가 4예이었으며, 우종은 20예(86.9%)에서 관찰되었다. 혈액배양 검사상 10예(43.4%)에서 원인균이 동종되었는데 Streptococcus viridans 5예, methicillin sensitive Staphylococcus aureus 2예, 그리고 Corynebacterium, Haemophillis, Gernella 각각 1예씩 이었다. 수술 적응증은 ACC/AHA 지침에 근거하였으며, 평균 외래 추적관찰기간은 27.6$\pm$23.3 (1∼97)개월이었다. 결과: 13예에서 승모판치환술을 시행하였는데 9예에서 기계판막을 사용하였고 4예에서 조직판막을 사용하였다. 10예에서 다양한 수기의 승모판성형술을 시행하였다. 동반수기로는 6예에서 대동맥판 치환술, 2예에서 삼첨판 성형술, 1예에서 변형된 미로수술, 1예에서 심실중격결손 낙합술을 시행하였다. 술 후 합병증으로는 출혈에 의한 재수술 2예, 종격동염 1예, 저심박출증 1예, 페렴 1예가 있었다. 술 후 30일 이내의 조기사망이나 병원 내 사망 및 판막 연관성 합병증은 없었다. 1예의 환자가 수술 3개월 후 다시 판막성형술을 받았고, 술 전 우종 전색에 의한 뇌경색을 보인 1예의 환자가 술 후 31개월에 뇌출혈로 사망하여 만기 전 체판막 연관성 사망률은 4.3%, 판막연관성 합병증은 8.6%였다. 1, 3, 5년 valve-related event free rate는 90.8%, 79.5%, 79.5%이었고 1, 3, 5년 생존율은 100%, 88.8%, 88.8% 이었다. 결론: 승모판 심내막염의 외과적 치료 시에는 감염된 조직의 완전 절제가 중요하며, 감염된 조직을 완전히 제거하면 대체물이나 수술 기법상의 차이가 결과에 미치는 영향은 크지 않을 것으로 판단되고, 술 전에 감염이나 우종 전색에 의한 뇌손상이 의심되는 환자에서는 술 후 추적관찰 중에도 뇌혈관 손상 가능성에 대해 주의 깊게 관찰하여야 할 것으로 생각된다.

• 한국전기전자재료학회논문지
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• 제24권12호
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• pp.939-943
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• 2011

In this paper, reliability of the two sandwiched MIM capacitors of $Al_2O_3-HfO_2-Al_2O_3$ (AHA) and $SiO_2-HfO_2-SiO_2$ (SHS) with hafnium-based dielectrics was analyzed using two kinds of voltage stress; DC and AC voltage stresses. Two MIM capacitors have high capacitance density (8.1 fF/${\mu}m^2$ and 5.2 fF/${\mu}m^2$) over the entire frequency range and low leakage current density of ~1 nA/$cm^2$ at room temperature and 1 V. The charge trapping in the dielectric shows that the relative variation of capacitance (${\Delta}C/C_0$) increases and the variation of voltage linearity (${\alpha}$/${\alpha}_0$) gradually decreases with stress-time under two types of voltage stress. It is also shown that DC voltage stress induced greater variation of capacitance density and voltage linearity than AC voltage stress.