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

무인화 무기체계의 안정적인 운용을 위한 Cybersecurity 및 Anti-Tamper의 적용

이민우,Lee, Min Woo 한국시스템엔지니어링학회 2020 시스템엔지니어링학술지 Vol.16 No.1

Due to the population of the Republic of Korea is getting less, the shortage of available troops has become a big issue. In response to this, the need for Unmanned weapon systems is rising. To operate an Unmanned weapon system near borderlines or low altitude, it is necessary to protect not only the system itself but also operational information communicated between the Unmanned system and control station, so that they should be safe using Cybersecurity measures. Besides, it is critical to protect a few core technologies applied to Unmanned weapon systems throughout the Anti-Tamper measures. As the precedent studies only focus partially, Cybersecurity or Anti-Tamper, it is acknowledged that comprehensive studies are needed to be conducted. This study is to incorporate both concepts into Korea's defense acquisition process. Specifically, we will outline the concepts and needs of Cybersecurity and Anti-Tamper, and briefly present ways to apply them simultaneously.

무기체계 획득에서 인공지능-시스템엔지니어링 융화를 위한 최상위 수준의 AI4SE, SE4AI 구현방안

이민우,Min Woo Lee 한국시스템엔지니어링학회 2023 시스템엔지니어링학술지 Vol.19 No.2

Artificial Intelligence (AI) is a prominent topic in almost every field. In Korea, Systems Engineering (SE) procedures are applied in Defense Acquisition, and it is anticipated that SE procedures will also be applied to systems incorporating AI capabilities. This study explores the applicability of the concepts "AI4SE (AI for SE)" and "SE4AI (SE for AI)," which have been proposed in the United States, to the Korean context. The research examines the feasibility of applying these concepts, identifies necessary tasks, and proposes implementation strategies. For the AI4SE, many attempts and studies applying AI to SE Processes both Requirements & Architectures Define, System implementation & V&V, and Sustainment. It needs Explainability and Security. For the SE4AI, the Functional AI implementation level, Quality & Security of the Data-set, AI Ethics, and Review policies are needed. Furthermore, it provides perspectives on how these two concepts should ultimately converge and suggests future directions for development.

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.

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.

선진국의 공사관리 벤치마킹을 통한 도로건설공사 감독자의 공사관리 향상방안

이민우,신은영,이교선,박환표,Lee, Min-Woo,Shin, Eun-Young,Lee, Kyo-Sun,Park, Hwan-Pyo 한국건설관리학회 2006 건설관리 : 한국건설관리학회 학회지 Vol.7 No.3

건설공사 현장에서 공공 발주처의 감독자는 공정관리, 품질관리, 안전관리 뿐만 아니라 공사 현장에서 발생하는 다양한 업무를 수행하고 있다. 특히, 한국도로공사 등 4개 공사는 공사특성에 맞게 전문화된 공사현장의 공사관리 업무를 추진하여 왔다. 그러나, 최근 민자사업의 물량 증가와 건설사업관리제도의 도입 등 건설환경의 변화_글 공공 발주처의 감독자는 보다 효율적인 공사관리방식을 도입하여 사업관리의 내실이 필요하게 되었다. 따라서, 본 연구는 국내 공공 발주처의 감독 운영시스템과 선진외국의 공사감독 제도를 조사 분석하여 국내 실정에 맞는 합리적인 공사감독 체계 개선방안을 마련하였다 특히, 본 연구는 고속도로 건설공시 공사감독자의 공사관리방안으로, 검측원의 육성방안과 건설공사 감독업무 매뉴얼, 교육프로그램 로드 맵 구축방안을 제시하였다. The construction supervisors of the public companies are usually responsible for process management, quality management, safety management, and many other various tasks that occur during construction project. Public companies such as Korea Highway Corporation have developed a framework and manual for management and supervision of construction projects. But, there has been the change of business environment such as increase of private investment project and the introduce of construction management system recently. It has been necessary for construction supervisor to streamline the current project management system in the owner's aspect in order to cope with the expected new challenges. Accordingly, this research has been investigated and analyzed the operation system between Korean supervisor and foreign supervisor in their public corporation. This research has suggested the advanced project management in their public corporation. Especially, this study has proposed the construction management manual for supervisors such as inspectors training, supervisors construction manual, and supervisors training road map.

입계확산처리된 Nd-Fe-B 소결자석에서 Dy의 확산에 미치는 Cu와 Al 분말의 혼합 효과

이민우,장태석,Lee, Min Woo,Jang, Tae Suk 한국분말야금학회 2016 한국분말재료학회지 (KPMI) Vol.23 No.6

We investigate the microstructural and magnetic property changes of $DyH_2$, $Cu+DyH_2$, and $Al+DyH_2$ diffusion-treated NdFeB sintered magnets with the post annealing (PA) temperature. The coercivity of all the diffusion-treated magnets increases with increasing heat treatment temperature except at $910^{\circ}C$, where it decreases slightly. Moreover, at $880^{\circ}C$, the coercivity increases by 3.8 kOe in Cu and 4.7 kOe in Al-mixed $DyH_2$-coated magnets, whereas this increase is relatively low (3.0 kOe) in the magnet coated with only $DyH_2$. Both Cu and Al have an almost similar effect on the coercivity improvement, particularly over the heat treatment temperature range of $790-880^{\circ}C$. The diffusivity and diffusion depth of Dy increases in those magnets that are treated with Cu or Al-mixed $DyH_2$, mainly because of the comparatively easy diffusion path provided by Cu and Al owing to their solubility in the Nd-rich grain boundary phase. The formation of a highly anisotropic $(Nd,\;Dy)_2Fe_{14}B$ phase layer, which acts as the shell in the core-shell-type structure so as to prevent the reverse domain movement, is the cause of enhanced coercivity of diffusion-treated Nd-Fe-B magnets.

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.