http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
오늘 본 자료
이헌덕(Heon-deok Lee),김정수(Jeoung Su Kim),김준홍(June Hong Kim),서용권(Yong Kweon Suh) 한국전산유체공학회 2012 한국전산유체공학회 학술대회논문집 Vol.2012 No.5
In this paper we report the method of CFD analysis of blood-flow through a coronary artery. We obtained 3D geometric model from a pair of angiographic projected images. We used ANSYS CFX for our simulation with Careau-Yasuda model as the non-Newtonian fluid model and obtained the pressure drop, velocity field, and streamlines of the 3D artery model. We found that the pressure drop increases linearly with the flow rate and that the pressure drop is manily determined by the viscous friction on the artery walls but not by eddy downstream of the stenosis.
3차원 캐버티 표면의 스톡스 유동 가시화 및 수치해석을 통한 표면 특성 연구
허효원(Hyo Weon Heo),이헌덕(Heon-deok Lee),정원혁(Won Hyuk Jung),조동식(Dong Sik Cho),서용권(Yong Kweon Suh) 한국가시화정보학회 2011 한국가시화정보학회지 Vol.9 No.3
?;?;In this study, we propose a method for characterizing fluid-mechanical properties of a fluid surface, such as surface dilatational and shear viscosity, by matching the flow visualization and the numerical simulation for a stokes flow in a three-dimensional cavity. The surface flow is driven by shear stress exerted on the free surface by an external gas flow. The external gas flow is simulated by using a commercial code, while the Stokes flow is calculated by an in-house code. We have found that the surface flow is very sensitive to the surface tension and other properties. The qualitative feature of the surface flow can be reproduced by the parameter tuning.
Kim, Jeum-Jong,Park, Yong-Dae,Kweon, Deok-Heon,Kang, Young-Jin,Kim, Ho-Kyun,Lee, Sang-Gyeong,Cho, Su-Dong,Lee, Woo-Song,Yoon, Yong-Jin Korean Chemical Society 2004 Bulletin of the Korean Chemical Society Vol.25 No.4
Esterification of aliphatic or aromatic carboxylic acids with alcohols using 2-(4-nitrobenzenesulfonyl)-4,5-dichloropyridazin-3(2H)-one (3) in the presence of base in organic solvents gave the corresponding esters in excellent yields
경남소재 일개조선소 근로자의 건강이상소견과 아르곤 용접과의 관련성
최우호 ( Woo Ho Choi ),진성미 ( Seong Mi Jin ),권덕헌 ( Deok Heon Kweon ),김장락 ( Jang Rak Kim ),강윤식 ( Yune Sik Kang ),정백근 ( Baek Geum Jeong ),박기수 ( Ki Soo Park ),황영실 ( Young Sil Hwang ),홍대용 ( Dae Yong Hong ) 한국산업보건학회 2014 한국산업보건학회지 Vol.24 No.4
Objective: This study was conducted to investigate the association between subjective distress symptoms and argon welding among workers in Gyeongnam Province shipyard. Method: 31 argon and 29 non-argon welding workers were selected as study subjects in order to measure concentrations of personal dust, welding fumes and other hazardous materials such as ZnO, Pb, Cr, FeO, MnO, Cu, Ni, TiO2, MgO, NO, NO2, O3, O2, CO2, CO and Ar. An interviewer-administered questionnaire survey was also performed on the same subjects. The items queried were as follows: age, height, weight, working duration, welding time, welding rod amounts used, drinking, smoking, and rate of subjective distress symptoms including headache and other symptoms such as fever, vomiting and nausea, metal fume fever, dizziness, tingling sensations, difficulty in breathing, memory loss, sleep disorders, emotional disturbance, hearing loss, hand tremors, visual impairment, neural abnormality, allergic reaction, runny nose and stuffiness, rhinitis, and suffocation. Statistical analysis was performed using SPSS software, version 18. Data are expressed as the mean ± SD. An χ2-test and a normality test using a Shapiro wilk test were performed for the above variables. Logistic regression analysis was also conducted to identify the factors that affect the total score for subjective distress symptoms. Result: An association was shown between welding type (argon or non-argon welding) and the total score for subjective distress symptoms. Among the rate of complaining of subjective distress symptoms, vomiting and nausea, difficulty breathing, and allergic reactions were all significantly higher in the argon welding group. Only the concentration of dust and welding fumes was shown to be distributed normally after natural log transformation. According to logistic regression analysis, the correlations of working duration and welding type (argon or non-argon) between the total score of subjective distress symptoms were found to be statistically significant (p=0.041, p=0.049, respectively). Conclusion: Our results suggest that argon welding could cause subjective distress symptoms in shipyard workers.
Chemoselective N-Benzenesulfonylation of Aliphatic Amines
Kim, Ho-Kyun,Park, Yong-Dae,Kim, Jeum-Jong,Lee, Me-Ho,Chung, Hyun-A,Kweon, Deok-Heon,Cho, Su-Dong,Yoon, Yong-Jin Korean Chemical Society 2003 Bulletin of the Korean Chemical Society Vol.24 No.11
Chemoselective N-benzenesulfonylation of aliphatic amines using 2-(4-nitrobenzenesulfonyl)-4,5-dichloropyridazin-3(2H)-one (2) gave the corresponding 4-nitrobenzenesulfonamides in good or excellent yield. This method is a simple, mild and general procedure for the chemoselective N-benzenesulfonylation of aliphatic amines.
서부 경남 일부 도장 작업장 근로자의 톨루엔 노출에 의한 건강 위해성 평가
이효민,최은석,홍대용,김장락,양진규,강민정,강문국,최우호,권덕헌,조미정 한국보건통계학회 2000 보건정보통계학회지 Vol.25 No.2
This study was performed to assess the health risk of toluene expected in painting workplace. The subjects were 87 workers of 43 painting workplaces in western Kyongnam Province. They were monitored through personal air samplers during working time and the samples were analyzed by gas chromatography. Subchronic daily intake of toluene was induced using Monte-Carlo simulation. For the settlement of exposure variables, exposure time, exposure frequency and inhalation rate were establiched to 8 hours per day, 280 days per year and 20 m'/day, respectively. The air concentration of toluene, inhalation rate and body weight were used in the form of distribution values to calculate subchronic daily intake of toluene. The reference dose of toluene was induced using toxicity value from Integrated risk information system (IRIS) database. For risk characterization, Monte-Carlo simulation was used for the induction of subchronic hazard index. The results of risk assessment were summarized as follows: Ⅰ. The air concentration of toluene was 39.313 ± 83.178 mg/m^3(mean ± standard deviation) ranging from 0.060 mg/m^3 to 444.108 mg/m^3. Among 87 subjects, only one exceeded threshold limit value(TLV-TWA). Ⅱ. Subchronic daily intake of 25th and 50th percentile on toluene simulated by Monte-Carlo simulation were 0.13 mg/kg-day, 0.54 mg/kg-day, respectively. Ⅲ. Inhalation reference dose of toluene was 0.13 mg/kg-day. Ⅳ. Subchronic hazard index of 25th and 50th percentile on toluene simulated by Monte-Carlo simulation was 1.17, 2.69, respectively. Adverse health effects of toluene to 65% of the workers would be expected in the selected painting workplaces because the hazard index of 35th percentile exceeded 1. So, we should not conclude there were no adverse health effects if it didn't exceed TLV-TWA