Monte Carlo 방법을 이용한 대기오염 배출률 예측의 불확실성 평가

정효준,김은한,서경석,황원태,한문희 한국환경과학회 2006 한국환경과학회지 Vol.15 No.4

인공신경망 이론을 이용한 충주호의 수질예측

정효준,이소진,이홍근 한국환경과학회 2002 한국환경과학회지 Vol.11 No.3

This study was carried out to evaluate the artificial neural network algorithm for water quality forecasting in Chungju lake, north Chungcheong province. Multi-layer perceptron(MLP) was used to train artificial neural networks. MLP was composed of one input layer, two hidden layers and one output layer. Transfer functions of the hidden layer were sigmoid and linear function. The number of node in the hidden layer was decided by trial and error method. It showed that appropriate node number in the hidden layer is 10 for pH training, 15 for DO and BOD, respectively. Reliability index was used to verify for the forecasting power. Considering some outlying data, artificial neural network fitted well between actual water quality data and computed data by artificial neural networks.

면역증강제로서의 Phellinus 屬菌의 항암 면역활성

김호정,김효준 한양대학교 이학기술연구소 1999 이학기술연구지 Vol.1 No.-

버섯류의 약리효과에 관한 연구로 버섯 중에 함유되어 있는 다당체들의 항암 및 면역 조절 작용 등과 관련하여 많은 연구가 진행되고 있으며, 최근에는 상황(桑黃)버섯으로 알려진 목질진흙버섯(Phellinus linteus)의 항암 약리작용이 관심의 대상이 되고 있다. 본 연구에서는 국내에서 채집한 P. igniarius(P-1), P. peni(P-2), P. robustus(P-3), P. linteus(p-5), P. B(P-8)의 5종류의 Phellinus 속균에 대하여 위암세포인 DLD-1 및 KATO Ⅲ, 대장암세포인 AGS와 같은 고형암 및 혈액암이 Jurkat T lymphma에 대하여 현미경적 관찰에 의한 약물효능 경시효과 및 효소분광학적 방법에 의한 유효농도(ED_(50))를 조사하여 항암효과를 평가하였다. 그 결과, DLD-1 및 DATO Ⅲ에 대하여 P. robustus(P-3), P. linteus(p-5), P. B(P-8)의 세 종류만이 40 ㎍/㎖의 범위에서 ED_(50)가 인정되었으며, AGS 및 Jurkat T cell의 경우에는 5종의 Phellinus spp. 모두에 있어서 각각 750, 180 ㎍/㎖의 높은 농도로 확인 되었다. 한편, 암세포 생자에 미치는 Phellinus spp.의 투여 효과를 검토한 결과, 처리하지 않은 대조군 암세포의 경우 30일 이상 생장을 지속하는 것에 비하여, Phellinus spp.를 200, 1000 ㎍/㎖ 처리한 경우 5가지 속균 모두에 있어서 암세포의 종류에 무관하게 3-7일의 단기간에 90%이상의 암세포가 사멸되는 것을 확인하였다. 이상의 결과로부터 Phellinus spp.는 위암세포에 특이적 효과를 보이는 것으로 나타났으며, 생체 내 함유량이 높은 경우에는 전반적으로 항암 효과를 나타내는 것을 확인하였다. Medicinal efficacy of mushrooms were focused on the anti-tumor immune regulatory effects of polysaccharieds in the pilcus of fruiting bodies. Recently, the Phellinus linteus is one of the most highlighted fungi for its remedial results. Five isolates in Phellinus spp., namely P. ingiarius, P. peni, P. robustus, P. linteus, and P. B were studied to evaluate the anti-tumor efficacy against several tumor cell lines including stomach cancer derived DLD-1 and KATO Ⅲ, colon cancer derived AGS and a blood lymphoma Jurkat T cells by microscopic observations of the cell viability and by the MTT and SRB enzyme-linked chromophoric assays. Two stomach cancer cells DLD-1 and KATO Ⅲ were arrested in its proliferation and lysed by three isolates of P. robustus, P. linteus, and P. B with the ED_(50) ranges of 40 ㎍/㎖ of hot-water extractives. Other carcinomas AGS and Jurkat T cells were suppressed by all of the isolates in Phellinus spp. tested, with the 750, 180 ㎍/㎖ of high ED_(50) concentrations, respectively. Also, time-course dose effects on the survival of cancer cells gave the same results with all the five isolate extractives. Tumor cells tested were survived over 30 days in vitro. However, those treated with Phellinus spp. extractives were extipated over 90% of cancer cells within a week. These results insisted that the Phellinus spp. has general carcinostatic effects and especially alimentary canal cancer cells are more susceptible than other tissues.

한국인 제2형 당뇨병 환자의 골격근에서 인슐린 신호전달체계의 결함

최준혁,이관우,김효정,이동훈,이종우,김정은,엄현채,김경미,최성이,정윤석,김현만 대한내분비학회 2002 Endocrinology and metabolism Vol.17 No.5

연구배경: 제2형 당뇨병에서 나타나는 인슐린 저항성은 간, 지방, 근육 같은 말초조직에서 인슐린의 작용이 떨어지는 것을 말한다. 제2형 당뇨병의 발생기전에 인슐린 저항성과 인슐린 분비능 저하가 같이 관여함은 잘 알려진 사실이다. 인슐린의 세포내에서의 저항성을 규명하기 위한 인슐린의 세포내 신호전달체계에 대한 연구가 활발히 진행되고 있으며 몇몇 연구에서 인슐린 저항성을 가진 골격근육에서 IRS와 관련된 PI3-kinase의 활성감소와 Akt kinase의 활성감소를 보고하고 있으나 아직까지 명확하게 그 기작이 설명되어지지 않고 있다. 본 연구에서는 정상성인, 제2형 당뇨병 환자를 대상으로 경구당부하검사 및 인슐린 클램프검사를 시행하고 인슐린 클램프 검사시 대상인의 근육을 채취하여 인슐린 신호전달 체계(IR-β, IRS, Akt(PKB, Rac) kinase, GSK-3)를 연구하였다. 방법: 연구대상자는 한국인으로서 경구당부하검사상 정상인 및 당뇨병 환자 각각 11명, 9명을 대상으로 하였으며, 정상인은 건강인으로 과거력상 당대사에 영향을 줄 질환이 없고, 현재 당대사에 영향을 줄 약물 복용 및 다른 소견이 없는 경구당부하검사상 정성 내당능을 보이는 대상자로 하였다. 당뇨병환자는 모두 제2형 당뇨병 환자로 이환기간이 만 5년 이내인 경우로 하고, 인슐린으로 치료하는 대상자는 제외하도록 하였다. 대상자의 연령, 체질량지수, 체지방량, 공복시 총콜레스테롤, 중성지방, 고밀도지단백 콜레스테롤 및 HbA1c, 인슐린, C-peptide를 측정하였고, "HOMA model"을 이용하여 베타세포의 기능와 인슐린저항성 정도를 평가하였다. 정상혈당클램프 검사(euhlycemic hyperinsulinemic clamp test)를 시행하고 인슐린 투입 전과 인슐린 투입 30분후, 두차례에 걸쳐 대퇴부 근육생검을 실시한후 western 법으로 IR-β, IRS, Akt kinase, GSK-3의 인산화량을 측정하였다. 결과: 정상인 11명과 당뇨병 환자 9명을 대상으로 하였으며 대상자의 평균 연령, 평균 체질량지수, 체지방량, 허리/엉덩이 둘레의 비(waist hip ratio; WHR)는 두 군간에 차이가 없었다. 평균 공복혈당은 정상군 98.0±0.3㎎/dL, 당뇨병군 208.1±16.5㎎/dL(p<0.05), HbA1c는 정상군 5.4±0.5%, 당뇨병군 9.2±0.6%(p<0.05)였다. "HOMA model"을 이용한 베타세포의 기능과 인슐린저항성은 정상군 56.4±8.5%, 1.4±0.2, 당뇨병군 72.2±52.3%(p<0.01), 10.2±6.3(p<0.01)였으며 정상혈당클램프 검사상 포도당 이용률은 정상군 8.2±0.6㎎/㎏/min, 당뇨병군 3.7±1.1㎎/㎏/min(p<0.01)로 정상군과 당뇨병군간에 유의한 차이를 나타내었다. Western blot법으로 IR-β, IRS, Akt kinase, GSK-3의 인산화량을 인슐린 투입전과 인슐린 투입 30분후 측정하였을 때 IR-β에서는 정상군이 103.9±2.3에서 241.3±18.6, 당뇨군이 108.9±2.2에서 198.7±6.3으로 증가하였다(p=NS). 이는 인슐린 투입후 당뇨병군이 정상군과 비교하여 인산화량의 증가정도가 통계적인 차이가 없었다. IRS에서는 정상군이 111.6±7.3에서 295.6±17.2, 당뇨군이 114.5±6.1에서 222.0±23.2로 증가하였으며(p<0.05), 인슐린 투입후 당뇨병군이 정상군과 비교하여 인산화량의 증가정도가 약 24% 감소하였다. Akt kinase에서는 103.4±6.0에서 416.8±29.5로 증가하였으며(p<0.01), 인슐린 투입후 당뇨병군이 정상군과 비교하여 인산화량의 증가정도가 약 43% 감소하였다. GSK-3에서는 정상군이 107.7±6.7에서 595.7±28.1, 당뇨군이 104.3±4.8에서 443.3±12.9로 증가하였으며(p<0.01), 인슐린 투입후 당뇨병군이 정상군과 비교하여 인산화량의 증가정도가 약 25% 감소하였다. 결론: 제2형 당뇨병 환자에서 정상인과 비교하여 인슐린 자극후 IR-β는 인산화량의 증가정도가 큰 차이가 없었으나, IRS, Akt kinase, GSK-3에서는 인산화량의 증가 정도가 감소되는 것으로 보아 상위 인슐린 신호전단체계부터 결함이 있는 것으로 생각된다. Background: The glucose uptake rate is the limiting step in glucose utilization and storage. The failure of insulin to stimulate glucose uptake in muscle appears to be a primary defect of insulin resistance. This study was undertaken to examine the effect of physiological hyperinsulinemia on the phosphorylation of the insulin receptor (IR-β), insulin receptor substrate (IRS), Akt kinase and GSK-3 in isolated skeletal muscle, in people with type 2 diabetes(n=9) and control subjects(n=11). Methods: 75g OGTT and euglycemic hyperinsulinemic clamp test were done. And vastus lateralis muscle was obtained before and 30 min into the euglycemic clamp. Western blots were performed for tyrosine phosphroylation of insulin receptor substrate (IRS) and phosphorylation of the insulin receptor(IR-β), Akt and GSK-3. Result: There were no statistical differences in the mean age, BMI and body fat between the control subjects and diabetic patients. The fasting blood sugar and HbA_1c in controls and diabetic patients were 98.0±0.3 and 208.1±16.5ng/dl, and 5.4±0.5 and 9.2±0.6%, and 1.4±0.2 in the control subjects, and 72.2±52.3%(p<0.01) and 10.2±6.3(p<0.01) in the diabetic patients, respectively. The insulin resistance from the euglycemic hyperinsulinemic clamp test were 8.2±0.6㎎/㎏/min and 3.7±1.1ng/㎏/min in the control subjects and in the diabetic patients, respectively(p<0.01). Compared with the normal controls, insulin-stimulated IR phosphorylation was no different to that in the diabetic patients. However, insulin-stimulated IRS phosphorylation, insulin-stimulated Akt phosphorylation and insulin-stimulated GSK-3 phosphorylation were reduced in the diabetic patients compared with the normal controls by 24, 43 and 25%, respectively(p<0.05). Conclusion: In Korean type 2 diabetic patients, the insulin resistance may be due to the impairment of the upstream insulin signal molecular network. Further studies will focus on determining whether these signaling defects are the cause of the development of insulin resistance, or secondary to the altered metabolic state, associated with type 2 diabetes mellitus (J Kor Soc Endocrinol 17:685∼697, 2002).

Zn-Fe 합금 도금강판의 점용접성에 관한 연구

민준기,신재경,안효영,서수정,서창제 成均館大學校 科學技術硏究所 1992 論文集 Vol.43 No.1

Spot welding is widely used in automobile assembly lines. Electroplating of Zn-Fe on steel sheets is increasingly used in assembly lines, because of its good spot weldability, formability and corrosion resistance. In this study, to evaluate spot weldability, tensile shear strength and cross tensile strength of steel sheets electroplated with Zn and Fe up to 0.7mm thickness were investigated, and these mechanical properties were compared with those of steel sheets electroplated with Zn only. The thickness of electroplated steel sheets was measured with SEM. The following conclusions were obtained. (1) In spot welding, the weldability lobe was getting wider and directed toward low currency direction, in steel sheets electroplated with Zn-Fe compared with those electroplated with Zn only. (2) Electrode force and welding time obviously affected the ultimate welding strength, and the range representing constant ultimate welding strength was observed. (3) When Zn-Fe were electroplated on steel sheets, the ductility ratio was increased in optimal welding condition, indicating that good weldability was obtained. (4) Around 8.5KA where optimal strength existed, by spot welding, the amount of the electroplated layer was observed to be reduced by approximately 15% in thickness.

하수관거 I/I 분석 프로그램 개발 및 구리시 관내 하수처리구역에 적용

황병기,김경원,정효준 대한상하수도학회 2002 상하수도학회지 Vol.16 No.4

A program was developed to compute infiltration and inflow analysis, and GUI was designed and added in the computational modules for a better understanding and convenient usage for users, named SM-Sewer. The system consists of four modules such as environmental database module for spatial data and their attribute data, filtering module for irregular data, missing data or outllers, I/l analysis module for continuously measured flow data, management module for I/l analyzed results. The modules were integrated using Visual Basic language under Windows Me environment for PC with a management panel, including menu bars, button bars, and tool bars. Using SM-Sewer, the system developed in this study, we performed I/l analysis for wastewater treatment areas of Guri city. According to the results of the analysis, ratio of infiltrated flow to total flow for station Guri-3 takes up 30% and was the highest among the 6 stations. To determine the rank for rehabilitation of sewer system, infiltration rate was computed by dividing by mean diameter and total length of sewer for infiltration. The analysed results show Guri-1 ranked as the first since the mean diameter and total length was large enough compared to the amount of infiltration. Accordingly, rehabilitation program for sewer should be gradually proceeded reflecting the rank determined based on the result of infiltration rate.

토끼에서 근육주사시 입자 크기에 따른 amoxicillin의 비교 약물동태학

박승춘,윤효인,오태광,장범수,배순이,조준형,정상희,이내경,김민규 충남대학교 수의과대학 동물의과학연구소 1998 動物醫科學硏究誌 Vol.6 No.-

To investigate the pharmacokinetic difference between the two amoxicillin (AMX) particles in rabbits after intramuscular injection (i.m.), both of AMX-S (particle size: 10 ㎍) and AMX-L (particle size: 100 ㎍) were injected into New Zealand White rabbits (1.2±0.3 ㎏) at a dose rate of 10 ㎎/㎏ of body weight. In this study, serum AMX concentrations were detected by microbiological assay with E. coli BE 1186 which shows high antibiotic sensitivity. After i.m. administration, AMX-S and AMX-L were best fitted as 1-compartment model with the absorption and elimination phase. The biological half-life (T_1/2, _k10) of AMX-S is 4.06±1.09 h and that of AMX-L 4.76±0.69 h. The serum maximal concentration time (T_max) of AMX-S and AMX-L were 0.88±0.17 h and 0.77±0.11 h, respectively. Maximal AMX concentration (C_max) (AMX-S: 5.71±0.62 ㎍/㎖, AMX-L: 5.04±0.25 ㎍/㎖) in serum showed a significant difference (p<0.05). In terms of bioequivalance, however, there was no difference between the two AMX's after i.m. injection in the basis of C_max and AUC.

A case study for the dispersion parameter modification of the gaussian plume model using linear programming

Jeong, Hyo Joon,Kim, Eun Han,Suh, Kyung Suk,Hwang, Won Tae,Han, Moon Hee 대한방사선방어학회 2003 방사선방어학회지 Vol.28 No.4

Radiological Emergency Preparedness after the Early Phase of an Accident : Focusing on an Air Contamination Event

Hyo-Joon Jeong,Won-Tae Hwang,Eun-Han Kim,Moon-Hee Han 대한방사선방어학회 2010 대한방사선방어학회 학술발표회 논문요약집 Vol.2010 No.04

Uncertainty Analysis on the Health Risk Caused by a Radiological Terror

Hyo-Joon Jeong,Won-Tqe Hwang,Eun-Han Kim,Moon-Hee Han 한국방사성폐기물학회 2010 한국방사성폐기물학회 학술논문요약집 Vol.8 No.1