복합재 블레이드의 1차원 보 모델링

이민우,배재성,이수용,이석준,전부일,Lee, Min-Woo,Bae, Jae-Sung,Lee, Soo-Yong,Lee, Seok-Joon,Jeon, Boo-Il 항공우주시스템공학회 2008 항공우주시스템공학회지 Vol.2 No.1

The three-dimensional finite element modeling of a composite rotor blade is very hard and requires much computation effort. The efficient method to model a composite beam is necessary for the dynamic and aeroelastic analyses of rotor blades. In this study, the beam modeling method of a composite rotor blade is studied using VABS. The computer program, VABS (Variational Asymptotic Beam Section Analysis), uses the variational asymptotic method to split a 3-D nonlinear elasticity problem into 2-D cross-sectional analysis and 1-D nonlinear beam problem. The VABS can produce the sectional stiffness coefficients of composite rotor blades with various cross section and initial twist/curvatures, and recover the original 3-D distribution of displacement/strain/stress fields. The results of various cross section beams show that VABS gives us the accurate results comparared to commercial codes and does not need much computation effort. It can be concluded that VABS provides the efficient method to establish the FE model of a composite rotor blade.

Ag(II)를 매개체로 사용하는 전기화학적 매개산화에 의한 NO_x 제거

이민우,박소진,이근우,최왕규,Lee, Min-Woo,Park, So-Jin,Lee, Kune-Woo,Choi, Wang-Kyu 한국방사성폐기물학회 2011 방사성폐기물학회지 Vol.9 No.3

전기화학적으로 생성되는 $Ag^{2+}$를 사용하는 MEO 공정에 의한 NO 제거에 전류밀도, $AgNO_3$ 농도, 세정 용액의 유속 및 NO-공기 혼합가스 유속이 미치는 영향을 조사하였다. 전류밀도가 증가할수록 NO의 산화 반응 속도 및 제거 효율이 증가하였으며, 0.1 M 이상의 $AgNO_3$ 농도 조건에서 ㅍ 농도가 NO의 제거 효율에 미치는 영향은 무시할 만 하였다. 세정용액의 유속이 증가할수록 NO의 제거효율은 점진적으로 증가한 반면에 NO-공기 혼합가스의 유속이 증가할수록 NO의 제거효율은 점진적으로 감소하였다. 실험 범위 내에서 도출한 최적조건을 적용한 MEO 공정 및 3 M 질산 흡수 공정을 복합적으로 적용하여 NO-공기 혼합가스를 처리하였으며, NO 및 $NO_x$의 제거 효율은 각각 95% 및 63%를 얻었다. The effects of the applied current density, the $AgNO_3$ concentration, the scrubbing liquid flow rate and the NO-air mixed gas flow rate on the NO removal efficiency were investigated by using $Ag^{2+}$ mediated electrochemical oxidation (MEO). Results showed that the NO removal efficiency increased with increasing the applied current density. The effect of the $AgNO_3$ concentration on the NO removal efficiency was negligibly small in the concentration of $AgNO_3$ above 0.1 M. When the scrubbing liquid flow rate increased, the NO removal efficiency was gradually increased. On the other hands, the NO removal efficiency decreased with increasing the NO-air mixed gas flow rate. As a result of the treatment of NO-air mixed gas by using the MEO process with the optimum operating condition and the chemical absorption process using 3 M $HNO_3$ solution as a scrubbing liquid, the removal efficiency of NO and $NO_x$ was achieved as 95% and 63%, respectively.

수변공원과 체육공원의 중요 속성

홍성권 ( Sung Kwon Hong ),이상우 ( Sang Woo1 Lee ),이민우 ( Min Woo Lee ),이상민 ( Sang Min Lee ) 한국환경복원기술학회 2007 한국환경복원기술학회지 Vol.10 No.6

현미와 다시마분말의 첨가수준을 달리한 증편의 품질특성

이민우,이인선,Lee, Min-Woo,Lee, In-Seon 한국식품조리과학회 2016 한국식품조리과학회지 Vol.32 No.2

Purpose: This study investigated the quality characteristics of Jeungpyun prepared with brown rice and sea tangle powder. Methods: The pH, volume, and spreadability of the dough and moisture content, color, texture and sensory evaluation of the Jeungpyun were performed. Results: The results showed that the pH of the dough decreased in all sample groups with the lapse of fermentation time, and ultimately revealed a pH ranging from 4.55-4.65. The spreadability of the dough significantly decreased as the substitute amount of the brown rice flour increased; the sample group with 1% sea tangle powder showed a significantly larger spreadability than the sample group with 2% sea tangle powder (p<0.05). The moisture content in the Jeungpyun showed a significantly lower result as the substitute amount of brown rice flour increased (p<0.05). Lightness (L) was reduced as the substitute amount of brown rice flour increased, and redness (a) and yellowness (b) also appeared to increase. As a result of measuring the texture, the 50% sample group with a high substitute rate of brown rice flour was observed to have high characteristics of hardness, gumminess and chewiness, and was low in cohesiveness. The result of the acceptance test showed that the sample group that substituted 25% brown rice flour and added 1% sea tangle powder was evaluated to have a significantly higher acceptance than the sample group that added 2% sea tangle powder in terms of color, texture and overall acceptance. Conclusion: The result of the acceptance test showed that the sample group that substituted 25% of brown rice flour and added 1% of sea tangle powder showed higher tendency in all acceptance attributes than the sample group that did not substitute the brown rice flour to show the possibility of developing the Jeungpyun with brown rice.

캐나다 북부 알버타주 데본기 후기 탄산염암 지역의 탄성파 층서

이민우,오진용,윤혜수,Lee, Min-Woo,Oh, Jin-Yong,Yun, Hye-Su 대한자원환경지질학회 2011 자원환경지질 Vol.44 No.6

캐나다 북부 알버타주의 데본기 후기 Grosmont층은 중생대 백악기와 데본기 후기 사이 형성된 침식 부정합면 하부에 위치하며 Ireton층의 셰일에 의해 4개의 단위로 구분되고, 상향 천해화(shallowing-upward)를 보이는 전형적인 대륙붕 환경이다. Grosmont층은 탄성파의 극성, 연속성, 주파수/간격, 진폭 등의 해석요소를 고려하여 4개의 단위(LG, UG1, UG2, UG3)로 구분할 수 있었고 반사파는 중-고진폭, 중-저주파수의 특징을 보이고 반사면은 연속성이 좋으며 서로 평행한 형태로 나타났다. 시추공의 암상자료를 바탕으로 대륙붕 또는 플랫폼(platform) 환경으로 해석할 수 있지만 반사파의 특성이나 형태만으로 순차층의 경계면과 퇴적환경을 인지하기란 쉽지 않기 때문에 이 연구에서는 부순차층세트(parasequence set)로 하여 층서 해석을 시도하였다. 침식 부정합면에 의해 퇴적계 연합체와 함께 부순차층세트가 형성되는데, 침식부정합면은 암상자료와 탄성파상의 카르스트화작용 및 침식면에 의해 그 인지가 가능하였다. 연구지역에 분포하는 Grosmont 탄산염암층은 플랫폼 및 대륙붕 환경으로부터 분지 방향의 플랫폼 주변부을 향하면서 층후가 점차 감소하는 쐐기형태로 발달하며 전진하는 시그모이드-오블리크(sigmoid-oblique) 형태의 음향특성을 갖는 것이 특징적이며, 이는 해수면 변동과 연계되어 퇴적작용이 진행되었음을 지시해주고 있다. 퇴적단위의 대부분은 주로 해퇴 및 저해수면 환경 하에서 형성된 것으로 해석되어 플랫폼 환경을 뒷받침해주는 증거가 된다. 특히, 고해수면 환경 하에서 형성된 퇴적체 하부의 셰일층은 반복되는 해퇴기간 동안 대부분이 박층으로 분포하는 것으로 해석된다. The Upper Devonian Grosmont Formation in northern Alberta, Canada, underlies the erosion unconformity that formed between the Cretaceous and Upper Devonian. The formation is divided into four units on the basis of intercalated shales and showing a typical shelf environment of shallowing-upward. It was possible to separate four units(LG~UG3), considering the seismic interpretation attributes of polarity, continuity, frequency/spacing and amplitude and showing the reflection characteristics of the medium-high amplitude, medium-low frequency, good continuity, and subparallel reflection events. The formation can be interpreted as shelf or platform, based on in-situ core data. However, it is difficult, only with reflection attributes and features, to recognize the boundaries and sedimentary environment of parasequence. Therefore, we try to interprete by parasequence set in this study. The parasequence set was formed by erosion unconformity with systems tracts. The erosion unconformity can be recognized by facies data and karst, erosional surface. Grosmont carbonate deposits ranging from platform and shelf to shelf slope are; by wedge-shaped strata of characterized by complex sigmoid-oblique progradational configurations, reflecting a depositional history of upbuilding and outbuilding in response to sea-level changes. Most of the sedimentary units is interpreted as platforms under regression and lowstand environments that support is evidences. In particular, shale layer at the basal part of the highstand systems tracts represents the regressive to lowstand of sea level.

현삼(玄蔘)이 $SO_2$로 손상된 흰쥐의 호흡기 조직에 미치는 영향

이민우,전종철,박동일,Lee, Min-Woo,Jeon, Jong-Choul,Park, Dong-Il 대한한방내과학회 2000 大韓韓方內科學會誌 Vol.21 No.4

Objective : This experiment was performed in order to study the effects of Scrophulariae Radix on the injured tracheal tissue induced So, in rats. Methods : Healthy adult male rats weighting about 250g were divided into 4 groups - the Normal group, the Control group, the group of Scrophulariae Radix administration for 5 days after $SO_2$, gas exposure(Sample I), and the group of Scrophulariae Radix administration for 10 days before and for 5 days after $SO_2$, gas exposure(Sample II). Results : In the trachea Control group, the lesion of the ciliated epithelium was severe and the mucus secretion of the respiratory tract was increased significantly. In the trachea of Sample I group, the lesion of the ciliated epithelium and the mucus secretion of the respiratory tract were decreased compared with Control group. In the trachea of Sample II group, the lesion of the ciliated epithelium and the mucus secretion of the respiratory tract were decreased compared with Control and Sample I group. conclusions : According to the above results, Scrophulariae Radix has significant effects on the injuried tracheal tissue caused by $SO_2$ in rats.

장기폭로 시험과 철근 부식 촉진시험의 시간적 상관성에 관한 연구

이민우,박상순,Lee, Min-Woo,Park, Sang-Soon 한국건설순환자원학회 2014 한국건설순환자원학회 논문집 Vol.2 No.4

부식촉진시험의 가장 확실하고 신뢰성이 높은 방법은 해양폭로 시험장에 직접 폭로시켜 철근부식모니터링을 실시하는 방법이지만 장기간이 소요되는 단점이 있다. 그래서 이를 대체하는 수단으로 많은 연구들이 진행되어 왔다. 하지만 부식촉진시험이 폭로환경의 어느 정도 기간에 상응하느냐는 상관성에 대한 규정은 정해져 있지 않은 상황이다. 본 논문에서는 간만대, 침지내 환경을 재현한 철근부식촉진시험과 장기폭로시험을 실시하였다. 환경조건을 변수로 시험을 실시하였으며, 반전지전위법을 통한 철근부식 모니터링을 실시하였다. 부식촉진 시험결과 시험조건 별 상대부식개시시점 도출을 할 수 있었으며, 내구성 해석 프로그램인 Life365와 염화물적정시험을 통해 염화물침투해석을 실시하였다. Recent interest in the increased structural performance and durability evaluation of this concrete structure in a salt damage environment is increasing. The most secure and reliable method of accelerated corrosion test is a method to carry out the rebar corrosion monitoring can be exposed directly to the marine test site exposure. However, long-term exposure testinghas the disadvantage that a long period is necessary. So, a lot of research on RC of salt damage environment have beenpromoted as alternatives to replace this. However, accelerated corrosion test, in the short term only is appropriate and is but an accelerated test method to evaluate the critical chlorine concentration, there is a difficult problem that you still get the answer. It is one of the correlation problems accelerated test correspond to a certain period of exposure environment. Therefore, in this study, to clarify the differences rebar corrosion beginning, through the actual corrosion accelerated test in corrosion time and laboratory test chamber of the structure of the marine environment results in both environments, it is an object of correlation coefficient derived.

자일로스와 들깨를 이용한 기능성 마카롱 개발 및 생리활성 품질 분석

이민우,최수영,유경미,임수연,정우석,황인경,Lee, Min-Woo,Choi, Soo-Yong,Yoo, Kyung-Mi,Lim, Soo-Yeon,Jung, Woo-Seok,Hwang, In-Kyeong 한국식품영양학회 2015 韓國食品營養學會誌 Vol.28 No.1

This study was conducted to investigate the effect of Perilla frutescens powder on physiological and sensory characteristics in macaron$\grave{e}$. The perilla powders were added to macaron$\grave{e}$ at a weight percentage of 0, 2.5 and 4%. Color values (L-value, redness and yellowness index), total phenolics, DPPH radical scavenging activity, textures, total sugar contents and sensory characteristics of macaron$\grave{e}$ made with varying levels of perilla powder were measured. In sensory evaluation, significant differences (p<0.05 and p<0.01) were shown in color, sweetness, nuttyflavor, texture and overall acceptability depending on the addition level of perilla powders.

SoC 전원 관리를 위한 인덕터와 커패시터 내장형 100MHz DC-DC 부스트 변환기

이민우,김형중,노정진,Lee, Min-Woo,Kim, Hyoung-Joong,Roh, Jeong-Jin 대한전자공학회 2009 電子工學會論文誌-SD (Semiconductor and devices) Vol.46 No.8

본 논문은 SoC 전원 관리를 위한 고성능 DC-DC 부스트 변환기 설계에 관한 것이다. DC-DC 변환기에서 일반적으로 전하 축전용으로 사용되는 인덕터와 커패시터를 칩 안에 집적하기 위해 그 크기를 크게 감소시키고, 스위칭 주파수를 100MHz로 하였다. 고속 동작에서 전압 방식의 제어를 선택하여 신뢰성을 높였으며 적절한 주파수 보상으로 안정적인 동작 특성을 확보하였다. 설계한 DC-DC 변환기는 thick gate oxide 옵션이 포함된 0.18${\mu}m$ CMOS 표준 공정으로 제작하였다. 내부 필터 커패시터를 포함한 칩의 면적은 8.1$mm^2$ 이고, 제어기가 차지하는 면적은 1.15$mm^2$ 이다. 부하 전류 300mA 이상에 대하여 4V의 출력을 얻는 변환기의 최대 효율은 76% 이상, load regulation은 100mA의 변화에 대하여 0.012% (0.5mV) 의 특성을 갖는다. This paper presents a design of a high performance DC-DC boost converter as a power module for SOC designs. It applied to this chip that reduced inductor and capacitor for integrating on a chip, and it operates with a switching frequency of 100MHz. It has reliability and stability in high switching frequency. The controller of DC-DC boost converter is designed by voltage-mode control method and compensated properly. The designed DC-DC converter is fabricated with the 0.18${\mu}m$ standard CMOS technology with a thick-gate oxide option. The overall die size is 8.14$mm^2$, and controller size is 1.15$mm^2$. The converter has the maximum efficiency over 76% for the output voltage of 4V and load current larger 300mA. The load regulation is 0.012% (0.5mV) for the load current change of 100mA.

과루지실탕(瓜蔞枳實湯)이 흡연(吸煙)으로 인(因)한 만성호흡기질환(慢性呼吸器疾患)의 임상적(臨床的) 고찰(考察)

이민우,박동일,Lee, Min-Woo,Park, Dong-I 대한한방내과학회 1998 大韓韓方內科學會誌 Vol.19 No.1

This study involved 45 man-smoker outpatients of Han-lim oriental medical hospital from Feb. 1, 1998 to May 31, 1998. The results of this study are as follows ; 1. In sex distinction, the average age was 51.9 years with persons aged 25 to 83 years. 40's and 50's are the most as 12 persons (26.7%) respectively, and in order of the next 30's and 60's are 7 persons (15.55%) respectively, more than 71 years are 5 persons (11.10%), less than 30 years are 2 persons. 2. In occupational distinction, farmers are the most as 20 persons (44.4%), and then common desk workers are 11 persons (24.44%), fishermen are 8 persons (17.78%), the others are 6 persons (13.34%) in that order. 3. In the distinction of chief complaint, cough 39 persons (88.67 %), sputum 29 persons (64.44%), dyspnea 13 persons (28.89%), loss of appetite 7 persons (15,56%), chest pain 5 persons (11.11%) in that order 4. the effects after dosage are as follows ; favorable turn of sputum is the most 89.66%, cough 64.10%, chest pain 60%, dypsnea 53.85%, loss of appetite 28.57%. As a whole, more than 68.32% was improved. As the above, it was thought that Kwarujisiltang administration was evidently effective on a chronic disease of the respiratory organs.