FR4 PCB면적과 Via-hole이 LED패키지에 미치는 열적 특성 분석

김성현,이세일,양종경,박대희,Kim, Sung-Hyun,Lee, Se-Il,Yang, Jong-Kyung,Park, Dae-Hee 한국전기전자재료학회 2011 전기전자재료학회논문지 Vol.24 No.3

In this study, the heat transfer capability have been improved by using via-holes in FR4 PCB, when the LED lighting is designed to solve the thermal problem. The thermal resistance and junction temperature were measured by changing the dimension of FR4 PCB and size of via hole. As a result, when the dimension was increased initially, the thermal resistance and junction temperature was decreased rapidly, the ones was stabilized after the dimension of 200 $[mm^2]$. Also, the light output was improved up to maximum 17% by formation of via-hole and expansion of dimension in FR4 PCB. Therefore, the thermal resistance and junction temperature could be improved by expansion of PCB dimension and configuration of via-hole ability.

미생물연료전지의 전기화학 원리 및 적용

김성현,Kim, Sung-Hyun 대한환경공학회 2009 대한환경공학회지 Vol.31 No.9

Thionin - Sodium Dodecyl Sulfate 계의 상호작용에 있어서 염 및 유기용매의 첨가효과에 관한 연구

김성현,송기동 ( Sung Hyun Kim,Ki Dong Song ) 한국공업화학회 1994 공업화학 Vol.5 No.5

양이온 색소인 thionin(Th)과 음이온 계면활성제인 sodium dodecyl sulfate(SDS) 사이의 상호작용을 흡수 spectra로 고찰하였다. 임계미셀농도(critical micelle concentration, CMC)보다 훨씬 낮은 premicellar 영역(S/D=10, 80및 160)에서 온도가 증가함에 따라 몰 흡광계수비가 증가하거나 감소함을 볼 수 있으며, S/D=160에서 Th-SDS계의 다분자 회합체가 생성하는 가장 안정한 온도 범위는 60℃ 이하임을 알 수 있었다. 한편 Th-SDS계에 첨가한 무기염 및 유기 용매의 농도가 증가함에 따라 γ-band와 J-band는 감소하나 α-band는 오히려 증가하는 경향이 나타났다. 이들의 α-band의 증가 순서는 무기염의 경우 Cl^- > ClO₄^- > SO₄^(2-) > NO₃^-로 나타나며, 유기용매인 경우는 2-propanol>ethanol>methanol>ethylene glycol로 나타남을 알 수 있다. The interaction between the cationic dye, thionin(Th) and the anionic surfactant, sodium dodecyl sulfate(SDS) has been investigated by absorption spectra. As the temperature of surfactant solution was increased in premicellar range(S/D=10, 80, and 160) which was much lower than the critical micelle concentration(CMC), the increment or decrement of the molar extinction coeffecient ratio appeared. It was found that the most stable temperature range of the oligomer aggregate in Th-SDS system at S/D=160 was below 60℃. With increasing the concentration of inorganic salt and organic solvents in Th-SDS system, α-band was increased, but γ-band or J-band was decreased. The orders of α-band increasing power were Cl^- > ClO₄^- > SO₄^(2-) > NO₃^- and 2-propanol>ethanol>methanol>ethylene glycol.

풀러렌-물 클러스터의 상호작용에 대한 양자 역학적 이론 연구

김성현,신창호,김지선,강소영,김승준,Kim, Sung-Hyun,Shin, Chang-Ho,Kim, Ji-Sun,Kang, So-Yung,Kim, Seung-Joon 대한화학회 2015 대한화학회지 Vol.59 No.1

풀러렌(fullerene)의 내부에 캡슐화될 수 있는 물 분자의 수와 물 분자들이 증가함에 따라 풀러렌의 안정적인 구조에 미치는 영향을 조사하기 위해 밀도 범함수 이론(density functional theory, DFT)을 이용하여 풀러렌-물 클러스터$(H_2O)_n@C_{60}$, (n=1-10)의 구조 변화에 따른 열역학적 안정성 및 결합에너지를 계산하였다. 각각의 구조들에 대해서 여러 이론 수준에서 최적화하였으며 진동주파수를 계산하여 가장 안정한 구조를 조사하고 IR 스펙트럼을 예측하였다. 또한 풀러렌 내의 물 분자 수가 증가함에 따른 수소결합의 세기 변화를 순수한 물 클러스터$(H_2O)_n$, (n=1-6)의 수소결합과 비교 분석하였다. The density functional theory (DFT) calculations on $(H_2O)_n@C_{60}$, (n=1-10) complexes have been performed to elucidate hydrogen interaction between fullerene and water clusters. The optimized geometries, harmonic vibrational frequencies, and binding energies are predicted at various levels of theory. The harmonic vibrational frequencies for the molecules considered in this study show all real numbers implying true minima. We also compare the H-bond interaction between $(H_2O)_n$ and $(H_2O)_n@C_{60}$, (n=1-10) clusters.

소나무(Pinus densiflora) 묘목의 생장에 미치는 납과 CO₂의 영향

김성현,홍선화,강호정,류희욱,이상돈,조경숙,이인숙,Kim, Sung-Hyun,Hong, Sun-Hwa,Kang, Ho-Jeong,Ryu, Hee-Wook,Lee, Sang-Don,Cho, Kyung-Suk,Lee, In-Sook 한국생태학회 2006 Journal of Ecology and Environment Vol.29 No.6

본 연구는 $CO_2$ 증가와 Pb 오염이 소나무 묘목에 미치는 영향에 대하여 조사하였다. 납 오염 토양(500 mg/kg-soil)과 비오염토양에 2년생 소나무를 식재한 후, $CO_2$ 농도를 380 PPM 혹은 760 ppm으로 조절한 배양기에서 3개월간 생육시킨 후, 소나무 묘목의 성장, 납 함량 변화 및 토양의 물리 화학적 변화를 조사하였다. 소나무의 생체량과 뿌리 길이는$CO_2$ 농도에 따라 유의적인 차이를 보이지 않았으나, 납에 의한 저해는 뚜렷이 나타났다. 납 오염 토양에서 토양중의 납 잔류랑은 $CO_2$ 농도에 영향을 받지 않았으나, 소나무 뿌리중의 축적량은 $CO_2$ 농도가 높으면 2배 정도 높았다. 이러한 결과는 $CO_2$ 농도 증가가 소나무 뿌리의 Pb 생물 이용성에 영향을 미치는 것을 시사한다. This work was investigated the effects of the elevated $CO_2$ and Pb contamination on the growth of Pinus densiflora. Two-years pine trees were planted in Pb-contaminated soils (500 mg/kg-soil) and uncontaminated soils, and cultivated for 3 months in the growth chamber where $CO_2$ concentration was controlled at 380 or 760 ppmv. The growth of P. densiflora were comparatively analyzed in 4 kinds of soil samples (CA : $CO_2$ 380 ppmv + Pb 0 mg/kg, CB : $CO_2$ 380 ppmv + Pb 500 mg/kg, EA : $CO_2$ 760 PPmv + Pb 0 mg/kg, EB : $CO_2$ 760 ppmv + Pb 500 mg/kg). It was measured the growth changes of the p. densiflora caused by $CO_2$ concentration and Pb contamination. The growth of P. densiflora was remarkably inhibited in the Pb-contaminated soil, although the biomass and the root elongations were not significantly affected by the elevated $CO_2$. These results suggested that the growth of p. densiflora was sensitively influenced by Pb contamination rather than $CO_2$ concentration. Compared to the initial soil, total Pb concentration in the soil samples was decreased at 760 ppmv $CO_2$ as well as at 380 ppmv $CO_2$ after 3 months. The accumulation of Pb in the roots at 760 ppmv $CO_2$ was two-fold of that at 380 ppmv $CO_2$, indicating that Pb bioavailability in the root of p. densiflora might be affected by the elevated $CO_2$.

현장 안전관리 감독자의 smartmaker 를 활용한 건설현장 근로자 정보 관리의 관한 연구

김성현,이지엽,손기영,Kim, Sung-hyun,Lee, Ji-yeob,Son, Kiyoung 한국건설안전학회 2020 한국건설안전학회 논문집 Vol.3 No.1

본 연구의 목적은 건설현장 근로자의 데이터 공유 시스템를 기반으로 건설재해 예방을 위한 근로자 정보 관리 모델을 구축하는 것이다. 이를 위해 첫째, 행연구 고찰을 통해 국내 건설현장의 외국인 근로자 현황을 파악하고, 정보 관리 애플리케이션에 대한 정보를 수집한다. 둘째, 스마트메이커 시스템을 활용하여 Brain storming을 실시하고, Aws를 통해 구축된 서버와 Family tree를 기반으로 개발된 애플리케이션의 기능을 분석한다. 셋째, 전문가 의견조사를 통해 개발된 정보 관리 모델의 경제성 및 효용성을 평가하고, 추가적인 기능 고찰 및 개선방안을 도출한다. 넷째, 개발된 정보 관리 모델의 국내 건설현장에서의 적용성에 대해 종합적으로 검토한다. 그 결과, 노무관리자와 현장 관리자 간의 보고체계가 단순화되어 노무자의 성실성 및 안전관리의 편리성이 있는 것으로 평가되었으며, 기능 추가 관련 사항으로는 자동 로그인 기능을 추가하여 편리성을 보완한다면 더욱 효과적일 것이라는 결론을 도출할 수 있었다. 본 연구의 결과는 향후 건설현장의 안전관리 시스템 구축연구의 기초자료로 활용될 것이다. In this study, an application was developed to reduce the work between labor and safety managers and to hire better workers when hiring workers. With the expected increase in foreign workers in the future, the number of illegal workers will also increase. As a result, accident and on-site management are becoming more difficult due to insufficient information collection of workers. Therefore, it was possible to secure on-site safety through an application that could collect accurate information and reduce the time of information exchange between safety managers and labor managers. In addition, the application was designed to help the safety manager identify the faithful workers more quickly when re-employment of the day laborers if many day laborers were assessed and filled out as they were. This anticipates the expected effect of shortening the construction period. The current application collected necessary information through an interview with the site manager. If the company collects more information needed in the field and has big data than it has collected necessary information so far, it will be highly competitive in the market as it can improve the completeness of applications by establishing opinions and reflecting information accordingly.

순천만 갈대근권 토양으로부터 얻은 PAH 분해세균의 특성 분석

김성현,강성미,오계현,김승일,윤병준,강형일,Kim Sung-Hyun,Kang Sung-Mi,Oh Kye-Heon,Kim Seung-Il,Yoon Byoung-Jun,Kahng Hyung-Yeel 한국미생물학회 2005 미생물학회지 Vol.41 No.3

This study was accomplished in order to collect fundamental data on microbial roles in recycling process of reed rhizosphere. Sunchon bay, which is considered as one of the marsh and mud environments severely affected by human activities such agriculture and fisheries, was selected as a model place. In our initial efforts, two bacterial consortia were obtained by enrichment culture using PAH mixtures containing anthracene, naphthalene, phenanthrene and pyrene as the sources of carbon and energy, and four pure bacteria capable of rapid degradation of PAH were isolated from them. Four strains designated as SCB1, SCB2, SCB6, and SCB7 revealed by morphological, physiological and molecular analyses were identified as Burkholderia anthina, Alcaligenes sp., Achromobacter xylosoxidans., and Pseudomonas putida, respectively with over $99{\%}$ confidence. Notably, Burkholderia anthina SCB1 and Alcaligenes sp. SCB2 were found to utilize anthracene and pyrene more quickly than naphthalene and phenanthrene, whereas Achromobacter xylosoxidans SCB6 and Pseudomonas putida SCB7 exhibited similar growth and degradation patterns except for pyrene. These facts suggest that the rhizosphere microorganisms capable of PAH degradation might be used to clean up the contamination sites with polycyclic aromatic hydrocarbons. 본 연구는 농업과 어업, 그리고 생태체험과 같은 인간들의 활동으로 인하여 상당히 영향을 받는 갯벌환경 중의 하나인 순천만을 모델장소로 갈대의 환경정화 기능에 있어 근권에 분포하는 미생물의 역할에 대한 기초 자료를 얻고자 수행하였다. 우선, 순천만의 갈대근권 토양을 시료로하고 anthracene, naphthalene, phenanthrene, pyrene 등이 첨가된 다환성 방향족 화합물(polycyclic aromatic hydrocarbons; PAH)을 탄소원 및 에너지원으로 하는 농화 배양을 통하여 두 개의 consortium을 획득하였다. 두 consortium으로부터 순수 분리된 우수한 PAH분해능을 갖는 4개의 균주(SCB1, SCB2, SCB6,그리고 SCB7)를 형태 및 생리학적 특성과 16S rRNA유전자서열을 기초로 분석한 결과 각 균주는 $99{\%}$ 이상의 신뢰도로 Burkholderia sp., Aicaligenes sp., Achromobacter sp., and Pseudomonas sp.로 동정되었다. 주목할 만한 점은 Burkholderia sp. SCB1과 Alcaligenes sp. SCB2는 naphthalene이나 phenanthrene보다 훨씬 안정되어 있는 구조의 anthracene이나 pyrene에서 더 빠른 성장률과 기질 분해율을 나타내는 것으로 밝혀졌다. 반면,Achromobacter sp. SCB6와 Pseudomonas sp. SCB7은 pyrene을 제외한 다른 시험기질에 대하여 유사한 성장 및 분해패턴을 나타내었다. 이러한 결과는 주요한 염습지 식물중의 하나인 갈대의 근권에서 살아가는 이들 PAH 분해 균주들이 PAH와 같은 물질로 오염된 근권 환경의 정화작용에 중요한 역할을 할 수 있음을 제시해 주었다.

기천(氣喘)에 대(對)한 문헌적(文獻的) 고찰(考察)

김성현,Kim, Sung-Hyun 대한한방내과학회 1992 大韓韓方內科學會誌 Vol.13 No.2

This study has been carried out to investigate the cause, symptom and treatment of Gi-Chun (氣喘) by referring to 32 literatures. The results were obtained as follows; 1. The factor causing Gi-Chun (氣喘) is almost damage of feeling (七情損傷). 2. The symptom of Gi-Chun (氣喘) is as follows. agony, breathing urgent, cold hand and feet, body tired, low appetite 3. The treatment of Gi-Chun (氣喘) is as follows. Sunpaeganggi(宣肺降氣), Jihaepyungchun(止咳平喘), gudam(去痰) 4. The drugs(herb) of Gi-Chun (氣喘) is as follows. Samatang(四磨湯), Sachiltang(四七湯), Sojaganggitang(蘇子降氣湯), Gilgyungjigaktang(桔梗枳殼湯), Gamisachiltang(加味四七湯), Gamisoyosan(加味逍遙散).

Immediate loading하에서 치근형 임프란트 주위 변연골 흡수에 대한 연구

김성현,한종현,Kim Sung-Hyen,Han Chong-Hyun 대한치과보철학회 2001 대한치과보철학회지 Vol.39 No.4

Alveolar bone changes after immediate loading on implants up to one year were observed by means of standard intraoral X-ray measurement which were taken at 3 month intervals. At the same time, bone density changes were observed according to digital subtraction method which is a becoming a more and more promising diagnostic tool for implants. Following results were obtained ; 1. There was no significant difference in the amount of alveolar bone loss implant type, sex and implant diameter, but there was difference according to case selection. In fully bone anchored prostheses cases, bone loss was $1.16{\pm}0.15m$ whereas, in partial edentulous cases, it was $1.84{\pm}0.08mm$. 2. Alveolar bone loss after immediate loading showed a higher degree of bone loss than after submerged loading in the initial three months. But there were no significant difference at the 12th month. 3. According to the one year bone density change observation at the alveolar bone surrounding the implant, significant change was observed vertically, whereas no significant change could observed horizontally. According to the above mentioned results, we can conclude that immediate loading of implants results in a higher degree of alveolar bone loss in one year than submerged loading. But since alveolar bone loss rate decreases to a reasonable rate after the initial 3 months of rapid bone loss, immediate loading of implants seems to be an acceptable treatment modality for patients with good bone conditions. Fully bone anchored cases showed an favorable outcome, but partial edentulous cases showed more bony resorption. So this cases considered in case selections. Bone density changes observation in the study was performed for only one year therefore a more longitudinal observation may be studied.

상폐(傷肺)에 의(依)한 비출혈(鼻出血)의 문헌적(文獻的) 고찰(考察)

김성현,Kim, Sung-Hyun 대한한방내과학회 1991 大韓韓方內科學會誌 Vol.12 No.1

It has been known that the nosebleeding is a king hemorrhage occured to be damaged yang-rak (陽略) & lung. the results obtained were as follows; 1. The cause of nosebleeding were divided internal external, these were lung-heat(肺實熱), wind-heat(風熱), dry-heat(煥熱), wind-cold(風寒), summer-heat(暑熱), and those were transporting of Liver-fire(肝火犯肺), Liver-kidney-fire(肝腎陰虛熱傷肺), Stomach-fire(胃火熾盛), Heart-fire(心火千肺). 2. The treatment of external ; Chungpaesulyul(淸肺泄熱), Yanghyuljihyul(凉血止血), Sanpungchungyul(散風淸熱), Jaeumchungjo(滋陰淸煥). 3. The treatment of internal ; Chungkansahwa(淸肝瀉火), Yanghuljihyul(凉血止血), Jayumganghwa(滋陰降火), Chunguysahwa(淸胃瀉火). The cause of nosebleeding was almost heat (fire), and the treatment were Sanpyo(散表) & Chungri(淸裏).