시론 - 꿈을 이루어 드립니다!

이용우,Lee, Yong-Woo 대한건축사협회 2009 建築士 Vol.2009 No.10

회원작품 - 남서울교회

이용우,Lee, Yong-Woo 대한건축사협회 2010 建築士 Vol.2010 No.9

선형변단면부재(線型變斷面部材)의 강도(剛度)매트릭스들의 계산상(計算上) 오차(誤差)

이용우,Lee, Yong Woo 대한토목학회 1985 대한토목학회논문집 Vol.5 No.2

얇은 관형단면(管形斷面)을 갖는 선형변단면부재(線型變斷面部材)를 포함(包含)하는 구조물(構造物)의 해석(解析)에 이용(利用)되는 강도(剛度)매트릭스를 정적분(定積分)을 사용(使用)하여 유도(誘導)하였다. "정형적분식(整形績分式)"으로 표현(表現)된 매트릭스 요소(要素)에 수치적(數値的) 불안정(不安定)을 주는 요인(要因)을 발견(發見)하고, 그 오차(誤差)를 살펴 보기 위하여 정적분(定積分)의 급수해(級數解)도 구(求)하였다. "정형적분식(整形績分式)"으로 규현(表現)된 정적분(定積分)의 사용범위(使用範圍)는 상대경사(相對傾斜)에 의(依)하여 규정(規定)하였다. The closed form of the stiffness matrix is derived in terms of closed forms of intergrals for analyses of plane frame members containing linerly tapered members with the cross section of thin-walled tube. The series expansion forms of these are also developed to study the errors in the closed form of the stiffness matrix. The useful limits of the closed form of integrals are defined in terms of the relative taper.

HPLC를 이용한 광합성색소 분석과 CHEMTAX 프로그램을 이용한 식물플랑크톤 군집조성 연구

이용우,박미옥,김윤숙,김성수,강창근,Lee, Yong-Woo,Park, Mi-Ok,Kim, Yoon-Suk,Kim, Seong-Su,Kang, Chang-Keun 한국해양학회 2011 바다 Vol.16 No.3

High-Performance Liquid Chromatograph(HPLC)를 이용하여 식물플랑크톤의 광합성색소를 분석한 결과를 토대로 CHEMTAX 프로그램을 이용하여 식물플랑크톤 군집조성을 추정하는 방법이 많이 이용되고 있다. CHEMTAX 프로그램은 식물플랑크톤 군집별(class level)로 체내에 존재하는 주요색소의 chlorophyll a에 대한 상대적인 비 값을 기초로 분석을 한다 본 연구는 국내 해역에서 분리한 식물플랑크톤 군집별 주요 종들이 가지는 광합성색소의 상대적인 비 값을 파악하고 이 자료를 기초로 남해안에 위치한 여자만과 가막만에서 측정한 광합성색소 분석결과에 대해서 CHEMTAX 프로그램을 이용하여 식물플랑크톤의 군집조성을 파악하였다. 국내해역에 존재하는 같은 군집종들 사이에서도 주요색소의 상대적인 비 값은 차이를 보였으며, 국외의 다른 해역에서 제시된 상대적인 비 값과도 상당한 차이를 보였다. 본 연구에서 얻은 비 값을 기초로 식물플랑크톤 군집조성을 분석한 결과, 다른 해역에서 제시된 비 값을 이용하여 분석한 결과와 유의한 차이를 보였다. 우점하는 군집(bacillariophyceae와 dinophytes)에 대해서는 5% 이내에서 차이를 보였으며, 비록 chlorophyll a에 대해서 낮은 기여도를 보이지만 pico와 nano 크기의 군집들(cyanophytes와 prasinophytes)에서는 상당한 차이(2배 이상)를 보였다. 비록 HPLC-CHEMTAX 분석방법은 식물플랑크톤 군집조성 연구에 유용하게 이용되고 있지만, 보다 정확한 결과와 식물플랑크톤의 생리, 생태를 이해하기 위해서는 연구해역에 존재하는 식물플랑크톤 종들에 대한 주요색소의 상대적인 비 값에 대한 연구가 계속적으로 진행되어야 할 것으로 판단된다. Many studies of the phytoplankton community structure have been conducted using the CHEMTAX program on the basis of the photosynthetic pigment concentrations measured by a HPLC (High-Performance Liquid Chromatography) technique. The CHEMTAX program determines the contribution of each phytoplankton class to total phytoplankton biomass (chlorophyll a) based on the ratios of marker pigment to chlorophyll a of phytoplankton group. In this study, the marker pigment/chlorophyll a ratios were investigated in phytoplankton species isolated from marine waters around the Korean peninsula. These results were used as the input pigment ratios of the CHEMTAX program to investigate phytoplankton community structure in Korean coastal waters (Yeoja and Gamak Bay). There were significant differences in the ratios of marker pigment to chlorophyll a among the different species within the same algal class. There was a significant difference between the values of our ratios and the previously used ratios in other regions of the world. When phytoplankton community composition was calculated using our initial ratios in Yeoja and Gamak Bay, our results were significantly different from the results calculated on the basis of initial ratios of marker pigment in phytoplankton suggested in other marine waters. The estimates of the contributions of the major algal groups (bacillariophyceae and dinophytes) to total chlorophyll a varied within 5% depending on the initial ratios chosen. The variations of estimates for the pico- and nanoplankton (cyanophytes and prasinophytes), which have relatively low contributions to total chlorophyll a, were higher than those for major algal group. Although the HPLC-pigment measurements combined with CHEMTAX analysis are useful for identifying and qualifying phytoplankton community structure, further researches for the pigment ratios of the dominant phytoplankton species presenting in a given area are also needed.

저밀도 지방단백질 수용체(Low Density Lipoprotein Receptor)의 생합성에 관한 연구 : (I) 저밀도 지방단백질 수용체 생합성 억제완화에 미치는 Ginsenoside의 영향

이용우,구자현,주충노,Lee, Yong-Woo,Koo, Ja-Hyun,Joo, Chung-No 생화학분자생물학회 1987 한국생화학회지 Vol.20 No.4

Ginsenoside의 고cholesterol혈증 억제작용 메카니즘을 규명하기 위해 고 cholesterol식이를 투여한 쥐의 low density lipoprotein(LDC) 수용체생 합성에 미치는 인삼 (Panax ginseng C.A. Meyer)의 사포닌 분획과 정제된 ginsenoside-$Rh_1$, $-Rb_2$, -Re, $-Rg_1$의 영향을 조사하여 다음과 같은 결과를 얻었다. 고cholesterol식이와 ginsenoside을 함께 투여한 쥐(시험군)의 혈청 cholesterol농도는 고cholesterol식이만으로는 사육한 쥐(대조군)에 비해 현저히 낮았다. 또한, 각 장기 (간, 신장, 정소, 부신피질)의 cholesterol 농도를 조사한 경우에도 위와같은 결과를 얻었다. 쥐 간의 $^{125}I$-LDL에 대한 LDL수용체의 결합활성은 시험군이 대조군에 비해 크게 증가되었으며, 다른 장기 (신장, 정소, 부신피질)의 경우에도 간의 경우와 유사하였다. 이것은 ginsenoside의 혈중 cholosterol 농도저하작용으로 인하여 고농도의 cholesterol에 의한 LDL 수용체의 생합성억제가 완화된 것으로 생각한다. The effect of saponin fraction from Panax ginseng C. A, Meyer and the purified ginsenoside-$Rh_1$, $-Rb_2$, -Re, $-Rg_1$ on LDL receptor biosynthesis in high cholesterol fed rat has been investigated, The cholesterol level of blood serum of high cholesterol diet-ginsenoside administered rat was greatly lower than that of high cholesterol diet administered rat (control) suggesting tbat the ginsenosides have hypocholesterolemic action, Analysis of LDL receptor from various organs such as liver. kidney, adrenal cortex and testis showed that the population of LDL receptors were significantly increased in the above organs suggesting that the hypocholesterolemic action might be brought about by the increase of LDL receptor.

전자선 조사에 따른 변압기유의 전기적 특성

이용우,조돈찬,홍진웅 ( Yong Woo Lee,Don Chan Cho,Jin Woong Hong ) 한국전기전자재료학회 1997 전기전자재료학회논문지 Vol.10 No.8

색소분석을 통한 곰소만 내 해수와 퇴적물 중 미세조류 생체량과 군집구조의 시공간적 변화

이용우,박미옥,윤지현,허성범,Lee, Yong-Woo,Park, Mi-Ok,Yoon, Ji-Hyun,Hur, Sung-Bum 한국해양학회 2012 바다 Vol.17 No.2

만의 대부분이 조간대(약 75%)인 전라북도 곰소만 내 해수와 퇴적물 중 미세조류의 생체량과 군집조성의 월 변화를 비교하기 위해서 1999년 2월부터 2000년 1월까지는 매월, 2000년 2월부터 12월까지는 격월로 high-performance liquid chromatograph(HPLC)를 이용하여 광합성색소 분석을 실시하였다. 또한 해수 중 미세조류의 군집구조를 조절하는 환경요인을 조사하기 위해서 수온, 염분, 영양염류, 용존산소, 화학적산소요구량을 분석하였다. 해수 중 미세조류의 월별 분포는 대체로 담수의 유입으로 인한 영양염류의 공급이 많은 시기에 높은 생체량(chlorophyll a)을 보였다. 퇴적물 중 저서미세조류의 생체량은 국내외 다른 갯벌지역에 비해서 상대적으로 낮았으며, 단위 면적당 적분한 해수 중 미세조류의 생체량에 비해서 2-3배 낮게 나타났다. 해수와 퇴적물 중 미세조류의 색소분석 결과, 규조류의 주요색소인 fucoxanthin 농도가 가장 높았으며, fucoxanthin과 chlorophyll a의 월 변화가 유사한 양상을 보여 곰소만 내 갯벌과 해수 중 미세조류는 규조류가 우점하는 것으로 판단된다. 그러나 조하대 표층 해수 중 미세조류 생체량(chlorophyll a)의 월 변화는 갯벌에 서식하는 저서미세조류 생체량의 월 변화와 다른 양상을 보였으며, 현미경 관찰을 통한 해수 중 미세조류의 종조성 분석 결과, 저서미세조류의 우점종인 저서성 규조류는 거의 관찰되지 않았다. 본 연구결과는 곰소만 갯벌에서 재부유되어 조하대로 공급되는 저서미세조류가 조하대 표층 생태계에 서식하는 생물에게 먹이원으로서의 기여도는 상대적으로 낮다는 것을 시사한다. 갯벌에서 재부유되어 조하대로 공급되는 미세조류의 정확한 평가와 함께 조하대에서 이들의 수직, 수평 거동과 관련된 심도 깊은 연구가 필요할 것으로 판단된다. To compare monthly variations of phytoplankton biomass and community composition between in seawater and sediment of the Gomso Bay (tidal flat: approximately 75%), the photosynthetic pigments were analyzed by HPLC every month in 1999 and every two months in 2000. Ambient physical and chemical parameters (temperature, salinity, nutrients, dissolved oxygen, and chemical oxygen demand) were also examined to find the environmental factors controlling structure of phytoplankton community. The temporal and spatial variations of chlorophyll a concentration in seawater were correlated well with the magnitude of freshwater discharge from land. The biomass of microphytobenthos at the surface sediments was lower than that in other regions of the world and 2-3 times lower than phytoplankton biomass integrated in the seawater column. Based on the results of HPLC pigment analysis, fucoxanthin, a marker pigment of diatoms, was the most prominent pigment and highly correlated with chlorophyll a in seawater and sediment of the Gomso Bay. These results suggest that diatoms are the predominant phytoplankton in seawater and sediment of the Gomso Bay. However, the monthly variation of chlorophyll a concentration in seawater at the subtidal zone was not a good correlation with that in sediment of the Gomso Bay. Although pelagic plankton was identified in seawater by microscopic examination, benthic algal species were not found in the seawater. These results suggest that contribution from the suspended microphytobenthos in the tidal flat to the subtidal zone of the Gomso Bay may be low as a food source to the primary consumer in the upper water column of the subtidal zone. Further study needs to elucidate the vertical and horizontal transport magnitude of the suspended microphytobenthos in the tidal flat to the subtidal zone.

Alcaligenes eutrophus 균주의 성장과 Ploy-${\beta}$-hydroxybutyrate 생합성에 대한 속도론

이용우,유영제,Lee, Yong-Woo,Yoo, Young-Je 한국미생물 · 생명공학회 1991 한국미생물·생명공학회지 Vol.19 No.2

It is very important to have a good kinetic model which considers the effects of both ammonium and glucose for the control and optimization of the poly-${\beta}$-hydroxybutyrate (PHB) fermentation. A kinetic model for the growth of Alcaligenes eutrophus and the biosynthesis of PHB under both ammonium and glucose limitation was proposed. Growth rate of residual biomass was expressed as a function of concentrations of residual biomass, glucose and ammonium having glucose inhibition. PHB production rate was expressed as a function of concentrations of residual biomass, glucose, ammonium and PHB content having ammonium and product inhibitions. Novel approaches were made to estimate the parameters in the model equations which considered two limiting substrates. Model parameters were evaluated by graphical and simplex methods. The proposed kinetic model fitted the data very well.

정상안압녹내장에서 당뇨 유무에 따라 분석한 안토시아노사이드, 은행잎추출물의 치료 효과

이용우,최철영,배정훈,김준모,Yong Woo Lee,Chul Young Choi,Jeong Hun Bae,Joon Mo Kim 대한안과학회 2014 대한안과학회지 Vol.55 No.8

Purpose: This study was performed to evaluate the effect of anthocyanoside and ginkgo biloba extract (GBE) in patients with normal tension glaucoma (NTG), according to the presence of diabetes mellitus (DM). Methods: A chart review of patients with normal tension glaucoma was retrospectively analyzed. All patients underwent a Humphrey visual field (HVF) test and logarithm of the minimal angle of resolution best-corrected visual acuity (log MAR BCVA) was measured over a 6 months period. Changes in mean deviation (MD), pattern standard deviation (PSD) of visual field and log MAR BCVA were compared among anthocyanoside, GBE and no medication (control) groups. Patients were divided according to the presence of DM. Results: A total of 406 NTG patients, including 151 DM patients, were included in the present study. MD was improved in the anthocyanoside and GBE groups, but not in the control group. PSD was not significantly different in all groups. BCVA was improved in the anthocyanoside group, but deteriorated in the control group. The results were similar in patients with or without DM. The generalized linear model demonstrated that systemic medication affected changes in visual indices. Conclusions: The results from the present study suggest that anthocyanoside and GBE may be helpful for improving visual function in some patients with NTG regardless of their DM status. J Korean Ophthalmol Soc 2014;55(8):1174-1179

무릎 연골 두께 아틀라스를 통한 손상 평가 기법

이용우,안천수,신지태,Lee, Yong-Woo,Bui, Toan Duc,Ahn, Chunsoo,Shin, Jitae 대한의용생체공학회 2015 의공학회지 Vol.36 No.2

Osteoarthritis is the most common chronic joint disease in the world. With its progression, cartilage thickness tends to diminish, which causes severe pain to human being. One way to examine the stage of osteoarthritis is to measure the cartilage thickness. When it comes to inter-subject study, however, it is not easy task to compare cartilage thickness since every human being has different cartilage structure. In this paper, we propose a method to assess cartilage defect using MRI inter-subject thickness comparison. First, we used manual segmentation method to build accurate atlas images and each segmented image was labeled as articular surface and bone-cartilage interface in order to measure the thickness. Secondly, each point in the bone-cartilage interface was assigned the measured thickness so that the thickness does not change after registration. We used affine transformation and SyGN to get deformation fields which were then applied to thickness images to have cartilage thickness atlas. In this way, it is possible to investigate pixel-by-pixel thickness comparison. Lastly, the atlas images were made according to their osteoarthritis grade which indicates the degree of its progression. The result atlas images were compared using the analysis of variance in order to verify the validity of our method. The result shows that a significant difference is existed among them with p < 0.001.