찬물속에 잠겨있는 등온 수직원통 주위에서의 자연대류에 관한 수치해석

황영규,이건호 成均館大學校 科學技術硏究所 1989 論文集 Vol.40 No.2

The truncate equations are formulated for natural convection flows adjacent to a vertical isothermal cylinder in cold, pure water. The resulting truncate equations, when reduced to ordinary differential equation by a nonsimilarity transformation, constitude a two point boundary-value problems. which are solved numerically using the computer code COLSYS. It is presented that the, numerical results corresponding to various values of the density extrimum parameter R(-1.014<R<0.5) and prandtl number. The results yield inferences regarding the ranges of density extrimum parameter R for existence of multiple-steady-state solutions, which have-at least two different solutions on the same physical conditions.

農民所得增大를 위한 고구마의 栽培와 利用에 관한 硏究

黃鍾奎,梁熙天,崔定植,權涌周 全北大學校 1977 論文集 Vol.19 No.-

New varieties of sweet potato Sinmi and Hwangmi were cultivated in the reclaimed hilly area of four kinds of soil series in Jeonbug province and their growth conditions such as cutting time, row spacing, application of fertilizers and plant growth regulators and covering effect were investigated. Besides these studies on cultivation of sweet potatoes, experiments on the change of chemical components of sweet potato tubers, adaptibility for storage and drying of sliced sweet potato tubers were carried out. The results are summarized as follows : 1. The early cutting of May 20, alley of 90 X 20cm, application of potassium(28kg/10a)and covering produced the high yield of sweet potatoes. The apllication of OED green did not increase the yield of sweet potatoes, 2. The yield of Hwangmi was higher than that of Sinmi. These two varieties of sweet potatoes grew well in all the test soil series except Bansan. By early cutting of May 20, the highest yield of Hwangmi was obtained in Songjung series soil and the highest yield of Sinmi was in Yesan. 3. Starch content was higher in Sinmi than in Hwangmi while yield of starch per unit area was high in Hwangmi because of its high yield of sweet potato tubers. Both Hwangmi and Sinmi showed very high water content of more than 70 per cent. The highest yield of total solid matter from Sinmi was on September 15 and that from Hwangmi on September 30. Sinmi and Hwangmi harvested on September 30 showed the highest starch content. 4. Variation in water content, starch, soluble sugar, protein and fat content during storage was minimum in the sweet potatoes stored in the temperature controlled storage chamber and was maximum in those stored in the cave under ground. As a result, percent of grade A sweet potatoes remaining was highest in the temperature controlled storage chamber and lowest in the cave under ground. 5. Hwangmi was more susceptible to Rhizopus nigricans than Sinmmi, especially under the humid condition. 6. Shape and thickness of slice did not affect the yield of dried sweet potatoes but affected the time needed for drying. Depending on the thickness and the shape of slice, variations of 36 hours and 12 hours in drying time were observed respectively. Drying table was most effective in drying of sweet potatoes and drying rack was also effective and required 2 days less time than mat. Dipping in water did not show any effect on drying time but improved the color of dried sweet potatoes.

순수한 찬물속에서 발생되는 수직자연대류의 수동력학적 안정성 : 0.32≤R≤0.50에서의 중립안정 Neutral Stability in the Range 0.32≤R≤0.50

黃英奎 成均館大學校 科學技術硏究所 1988 論文集 Vol.39 No.1

This work is concerned principally with the derivation, for various values of the density extremum parameter R(0.32 ≤ R ≤ 0.5), of the numerical results that predict the physical conditions for neutral stability to the base flow generated by natural convection adjacent to a vertical, isothermal plate in cold, pure water. The present numerical study includes neutral stability results for the region of the flows corresponding to 0.32≤R≤0.50. In particular, neutral stability curves are obtained to R=0.32, R=0.34 for the two base flows corresponding to the upper and lower branch solutions. The flow corresponding to the upper solution, in general, has a higher critical Grashof number G* than does the flow of the corresponding lower solution. With the results of the present study, it is found that the strong dependence of the limit of stability on the shape of velocity profile is equivalent to the large influence of the buoyancy force on stability.

간호대학생이 지각하는 임상실습지도자의 교수효율성과 임상실습만족도의 관계

황현아,김희진,김예지,이규희,이영롱,박성희,손수빈 이화여자대학교 간호과학대학 2012 이화간호학회지 Vol.- No.46

Purpose: The purpose of this study was to investigate the relationship between teaching effectiveness and clinical practice satisfaction among nursing students. Method: The subjects of this study were 107 junior and senior nursing students in E university. Data were collected using self-reported questionnaire including general and practicum related characteristics, teaching effectiveness of clinical instructors and clinical practice satisfaction from September 12 to September 21, 2011. Collected data were analyzed by SPSS 19 program using t-test, ANOVA with Scheffe test, and Pearson`s correlation coefficients. Result: The mean score of teaching effectiveness was 3.35(±.51), and mean of clinical practice satisfaction was 3.19±.47. There were significant differences of teaching effectiveness of clinical instrutor by satisfaction of overall clinical practicum(F=8.332, p<.001), satisfaction of practice hour(F=3.230, p=.044), and satisfaction of major(F=9.883, p<.001). There were significant differences of clinical practice satisfaction by grade(t=2.274, p=.025), motive of choosing nursing science as a major(F=3.329, p=.007), satisfaction of overall clinical practicum(F=17.437, p<.001), satisfaction of practice hours(F=9.925, p<.001), and satisfaction of nursing major(F=12.748, p<.001). Relationship between teaching effectiveness of clinical instructor and clinical practice satisfaction showed positive correlation(r=.704, p<.001). Conclusion: In this study, teaching effectiveness of clinical instructor was related with clinical practice satisfaction. Therefore, we should consider improving teaching effectiveness of clinical instructor to improve clinical practice satisfaction.

납노출지표와 적혈구내 protein kinase C 활성도의 연관성

황규윤,황보영,안현철,김용배,리갑수,이성수,안규동,이병국 大韓産業醫學會 2001 대한직업환경의학회지 Vol.13 No.4

목적 : Protein kinase C는 칼슘-인지질 의존형인산화 효소로 'H VJ'tfO에서 납에 의하여 활성화되지만, 납에 노출된 인체내에서 그 영향을 평가한 경우는 얼다. 본 연구의 목적은 납에 직업적으로 노출되는 근로자를 대상으로 납 노출이 적혈구막의 단백질내에서 PKC 활성에 의한 인산화 수준에 영향을 주는지 알아보고자 하였다. 방법 : 1998년부터 국내 납 근로자를 대상으로 납에 의한 건강 영향조사가 4년간의 코호트 연구로 실행하였다. 1차년도에 630명의 납 근로자와 135명의대조군이 조사되었고 이들중 본 연구에서는 직업적노출이 되는 사업장에 근무하는 212명의 근로자를대상하였다. 156명의 남자와 56명의 여자 근로자를 대상으로 인구학적, 과거병력, 직업력 등을 구조화된 설문과 면접으로 조사되었고 납 노출 평가는 혈중 납농도 및 ZPP, 경골중 납농도를 측정하였다. PKC의 활성도는 적혈구막 단백질내 PKC 의존형인산화 수준으로 평가하였다. 적혈구막 단백질인spectrin과 band 4.9의 후인산화수준을 측정하여각 납 노출지표(혈중 납, ZPP, 경골중 납. 노출기간)와의 관련성은 다중회귀분석을 이용하였다. 결과 : 조사대상자의 평균(SD) 연령은39.1(10.0)세, 근무기간은 8.1(6.5)년 이었으며, 경골중 납농도는 범위가 0.8에서 290.8 trg Pb/gbone mineral로 평근(SD) 34.4(35.2) rig Pb/gbone mineral이었다. 적혈구막 단백질의 후인산화수준은 개인간 변이가 매우 컸으며, spectrin은 평균(SD) 540 7(304.1), band 4.9 SfkDa는198.6(78.2), 48 kDa는 247.7(83.3) PSL이었다.경골중 납농도와 노출 기간은 이들 후인산화 수준과역상관성을 보였으나(p(0.05), 혈중 납 농도와 ZPP는 상관성이 없었다(p)0.05). 가능성 있는 혼란변수를 통제한 상태에서도 경골중 납 농도와 노출기간은 이들 후인산화수준과 유의한 회귀계수를 나타내었다. 결론 : 만성적 납 노출에 의하여 적혈구내 PKC활성도는 영향을 받아 증가되어있는 것으로 평가되어 적혈구막 단백질의 인산화수준은 납의 노출지표로 이용될 수 있을 것이다. 납의 신경독성은 부분적으로 PKC의 활성도왁 관련되어 있을 기전을 배제하기 어렵기 때문에 PfC 활성도와 신경행동학적 기능과의 관련성 평가가 진행되어야 할 것이다. Objectives : Protein kinase C(PKC) , a calcium and phospholipid dependent enzyme, is activated by lead in vitro at picomolar concentrations. However, the effect of lead on PKC has never been studied in a human population. The purpose of the study was to evaluate whether lead exposure was associated with PKC mediated-phosphorylation in erythrocytes among lead workers. Methods : Two hundred and twelve lead workers were studied. To determine the levels of phosphorylation ir vivo, an in vivo back phosphorylation technique was used by adding PKC and γ-32P to preparations of erythrocyte membranes. We measured back phosphorylations of erythrocyte membrane proteins, spectrin, and 52 kDa and 48 kDa, as an indirect measure of PKC activation if vivo. Results : The mean(SD) age and exposure duration was 39.1(10.0) years and 8.1(6.5) years, respectively. Tibial lead ranged from 0.8 to 290.8 μg Pb/g bone mineral with a mean (SD) of 34.4(35.2) μg Pb/g bone mineral. The means(SD) of back phosphorylation levels of the three proteins were 540.7(304.1), 198.6(78.2), and 247.7(83.3) photostimulated luminescence units (PSL), respectively, by phosphoimager. After adjustment for potential confounding factors, tibial lead and exposure duration were significantly and inversely associated with back phosphorylation levels. One unit of increase in tibial lead (1 μg Pb/g bone mineral) is associated with a decline in spectrin, band 4.9 52 kDa, and band 4.9 48 kDa back phosphorylation levels by 1.4(p〈0.05), 0.34(p〈0.05), and 0.47(p〈0.01), respectively However, there were no associations between the back phosphorylation levels and either blood lead or ZPP levels. Conclusions : These findings suggest that the PKC activity in erythrocytes is increased by chronic lead exposure and that erythrocyte membrane protein phosphorylation may be a biomarker of lead exposure.

적응 루프법을 이용한 진화적 구조 위상 최적설계

황승민,박재용,임민규,오영규,한석영 한국공작기계학회 2009 한국공작기계학회 춘계학술대회논문집 Vol.2009 No.-

This paper presents a reliability-based topology optimization (RBTO) using bi-directional evolutionary structural optimization (BESO). Topology optimization is formulated as volume minimization problem with probabilistic displacement constraint. Young's modulus, external load and thickness are considered as uncertain variables. In order to compute reliability index, four methods, i.e., RIA, PMA, SLSV and ADL(adaptive-loop), are used. Reliability-based topology optimization design process is conducted to obtain optimal topology satisfying displacement and reliability index constraints with the above four methods, and then each result is compared with respect to numerical stability and computing time.

급성 골수성 백혈병 환자에서 관해 유도 항암 화학요법 후 발생한 베르니케 뇌증

황진원,정재현,서광원,최병진,송영진,김종윤,이은지,임홍규,이상민 인제대학교 2009 仁濟醫學 Vol.30 No.-

Wernicke's encephalopathy is characterized by the triad of ocular symptoms, ataxia, and mental confusion and neuropsychiatric condition generally caused by acute thiamine deficiency. Although it is common in the severe alcoholics, several other causes also have been identified, such as total parenteral nutrition (TPN) use, hyperemesis gravidarum, anorexia nervosa, hemodialysis, uremia, and acquired immunodeficiency syndrome(AIDS). Chemotherapy in patient with malignanacy and long term total parenteral nutrition following bone marrow transplantation are related with Wernicke's encephalopathy. A 48-year-old woman had been treated with Daunorubicin and Cytarabine for remission induction chemotherapy of acute myeloblastic leukemia and intravenous hyperalimentation due to persistent hematochezia and ileus caused by infiltration of leukemic cell in terminal ileum. She suddenly complained of diplopia, tremor, and mental confusion at 32th day after chemotherapy and generalized tonic-clonic seizure at 34th day after chemotherapy. The diagnosis of Wernicke's encephalopathy was made with clinical presentations and brain MRI. Brain MR T2-weighted & Flair image revealed a high signal intensity lesions bilaterally at the medial thalamus and peri-acueductal grey matter of the midbrain. The patient was successfully treated with vitamin B1. We presented a case of acute Wernicke's encephalopathy developed after remission induction chemotherapy followed by intravenous hyperalirnentation in a patient with acute myeloblastic leukemia.

영어 사역동사 보충절의 통사구조

황규홍,민지영 東亞大學校 2005 東亞論叢 Vol.42 No.-

This paper aims to investigate the syntax of causative verb clausal complements of make, have, let, and help in English within the minimalist framework outlined in Chomsky (1999, 2000, 2001), by emphasizing their constituency and categorial status. Generally, those syntactic causative verbs select bare infinitives as their complements, even though help also exceptionally takes another type of complements : to-infinitives. I put forward the proposals: i ) such causative verb clausal complements are single constituents, by examining a variety of constituency tests : coordination, reflexives, and expletives, and ii ) their categories are TPs whose head T is defective, lacking ∮ -complete.

연폭로 근로자들에서 빈혈증 관련 인자에 관한 연구

황보영,김용배,김화성,이성수,안규동,이병국 순천향대학교 교수학습개발센터 2004 Journal of Soonchunhyang Medical Science Vol.10 No.3

Objectives : This study intended to obtain the interrelationship of lead exposure indices and anemia related factors for the better health management of lead exposed workers. Methods : 502 male workers in storage battery industries as lead exposed group and 106 male office workers as contorl group were selected for this study. The examined variables wer age, work duration, smoking and alcohol crinking habit, blood zinc protoporphyin concentraion (ZPP), blood lead concentration (PbB), urinary δ-aminoevulinic acid (ALAU), hemoglobin (Hb), hematocrit (Hct), serum calcium (S-Ca), serum iron (S-Fe), total iron binding capacity (TIBC), and percentage trasferrin saturation (PTS). Results : The means of ZPP, PbB ALAU in lead exposed proup were 58.4±35.7 ㎍/㎗, 27.6±10.9 ㎍/㎗, and 1.61±2.00 mg/ℓ, respectively. These three values in lead exposed group were significantly higher than control group (P<.05). The means of Hb, Hct, S-Ca, S-Fe, TIBC, PTS in lead exposed group were 15.3±1.1 g/㎗, 47.2±4.5 %, 9.4±0.4 ㎍/㎗, 124.0±67.5 ㎍/㎗, 317.1±68.5 ㎍/㎗, and 38.7±15.2 %, respectively. Hb, Hct, S-Ca, S-Fe, and TIBC in lead exposed group were significantly lower than contrl group (P<.05). PTS was no significant difference in lead exposed group and control group (P> .05). Hct, S-Ca, S-Fe, PTS were significant positive correlation with Hb and ZPP, corrected PbB, AlAU were significant negaitive correlation with Hb in lead exposed group (P< .05). On multiple regression using ZPP as a dependent variable and PbB, S-Ca and S-Fe as independent variables after adjustment for possible confounder such as age, smoking and drinking habit, Pbb, S-Ca, S-Fe and age contributed to ZPP. Conclusions : As the result of this study, it was suggested that inclusion of S-Ca, S-Fe, PTS measurement as a anemia screening test for lead workers was highly recommended for the effective prevention and early diagnosis of anemia.

有限要素法을 利用한 Burgers 방정식의 Computer Modeling

黃英奎 成均館大學校 科學技術硏究所 1985 論文集 Vol.36 No.1

A finite element method is applied to solve Burgers' equation which is an initial-boundary value problem of partial differential equation in one space dimension and time. By using a code PDECOL implementing the method of lines with a finite element collocation procedure, Burgers' equation was solved for 8 different meshs including uniform meshs and nonuniform meshs with a variable time step size. The computed solution did not converge at t=0.476 for a uniform mesh with less than 30 elements. When a nonuniform mesh with 18 elements per time step was used by concentrating the mesh in the shock region as the wave steepens, the numerical scheme converged and showed the same accurate results as that of uniform mesh with 30 elements per time step.