소형 MR감쇠기의 성능 실험에 기초한 준능동 제어 시스템

민경원,Min Kyung-Won 한국전산구조공학회 2006 한국전산구조공학회논문집 Vol.19 No.3

이 논문에서는 소형 다층 구조물의 진동제어에 적용하기 위한 복합모드의 자기유변유체(MR) 감쇠기를 개발하였다. 우선, 도식적으로 전단, 유동, 복합모드 MR감쇠기의 형태를 설계조건과 함께 표현하였고, 각각의 모드에 대하여 자기장에 따른 감쇠력을 예측하기 위한 해석모델을 유도하였다. 다음으로 적당한 크기의 복합모드 MR감쇠기를 제작하고 자기장에 따른 감쇠특성을 시간영역에서 평가하였다. 마지막으로 지진하중을 받는 소형구조물에 제작된 MR감쇠기가 준능동 제어기로 제어하였을 때의 성능을 수치적으로 평가하였다. In this paper, mixed mode magneto-rheological(MR) damper, which is applicable for vibration control of a small scale multi-story structure, is devised. First, the schematic configurations of the shear, flow, and mixed mode MR dampers are described with design constraints and then the analytical models to predict the field-dependent damping forces are derived for each type. Second, an appropriate size of the mixed mode MR damper is manufactured and its field-dependent damping characteristics are evaluated in time domain. Finally, the performance of the manufactured MR damper which is semi-actively applied to a small scale building excited by earthquake load, is numerically evaluated.

회전 막유화에 의한 알지네이트 미소 구체의 제조

민경원,염경호,Min, Kyoung Won,Youm, Kyung Ho 한국막학회 2021 멤브레인 Vol.31 No.1

SPG (Shirasu porous glass) 원통형 막을 회전 시키는 회전 막유화를 사용하여 칼슘 알지네이트 미소 구체를 제조할 때, 단분산 미소 구체를 제조하기 위한 회전 막유화 공정변수들의 최적 조건을 결정하였다. 회전 막유화의 공정 변수로는 막의 회전 속도, 막간 압력차, 연속상에 대한 분산상의 비율, 알지네이트 농도, 유화제의 농도, 안정제 농도, 가교제 농도 및 막의 세공 크기를 설정하고, 이들 변수로 제조된 알지네이트 미소 구체의 크기와 단분산성에 미치는 영향을 검토하였다. 이 결과 회전 막유화의 공정 변수들 중에서 막모듈의 회전 속도, 유화제의 농도, 가교제의 농도가 증가 할수록 미소 구체의 크기가 감소하였으며, 반면에 연속상에 대한 분산상의 비율, 막간 압력차, 알지네이트 농도가 증가할수록 미소 구체의 크기가 증가하였다. 세공 크기 3.2 ㎛인 SPG막을 사용한 회전 막유화에서 공정변수 조절을 통해 최종적으로 입자 크기가 4.5 ㎛의 단분산 알지네이트 미소 구체의 제조가 가능하였다. When preparing calcium alginate microspheres using rotating membrane emulsification that rotates SPG (Shirasu porous glass) tubular membrane in the continuous phase, the optimal conditions of rotating membrane emulsification process parameters for producing monodisperse microspheres were determined. We determined the effects of process parameters of rotating membrane emulsification (the rotating speed of membrane module, the transmembrane pressure, the ratio of dispersed phase to continuous phase, the alginate concentration, the emulsifier concentration, the stabilizer concentration, the crosslinking agent concentration, and the membrane pore size) on the mean size and size distribution of alginate microspheres. As a result, the size of the microspheres decreased as the rotating speed of membrane module, the emulsifier concentration, and the crosslinking agent concentration increased among the process parameters of rotating membrane emulsification. On the contrary, as the ratio of dispersed phase to continuous phase, the transmembrane pressure, and the alginate concentration increased, the size of the microspheres increased. In the rotating membrane emulsification using an SPG membrane with a pore size of 3.2 ㎛, it was possible to finally prepare monodisperse alginate microspheres with a particle size of 4.5 ㎛ through the control of process parameters.

흥인지문의 단순 구조모델 및 지진해석

민경원,박성아,Min, Kyung-Won,Park, Sung-Ah 대한건축학회 2011 대한건축학회논문집 Vol.27 No.4

This study deals with derivation of equivalent horizontal stiffness and seismic analysis of Heunginjimun based on ambient vibration test, which give its natural frequencies, modes and damping ratios. Natural frequencies are identified as invariant values. Lowest two lateral modes in weak axis shows that columns under acceleration sensing moves in parallel with same phase. They mean that Heunginjimun behaves linearly and not individually under ambient vibration. Beam-column joints are much weak compared to individual column stiffness. All these founding allows Heunginjimun to be modelled as dynamic rigid body with two stories having vertical compressive forces, which are estimated by self loads. Rigid body model with two degrees of freedom is suggested and characteristic equation is derived. Lateral stiffnesses of the model are found from the equation with identified natural frequencies. These identified data make possible to perform equivalent static and dynamic seismic analyses by Korean Building Code and Commentary-2009. Story drifts of the model are obtained by two analyses showing that the second story drift exceeds the allowable drift.

라이소자임 분자각인 P(AN-co-MA) 막의 제조와 특성

민경원,유안나,염경호,Min, Kyoung Won,Yoo, Anna,Youm, Kyung Ho 한국막학회 2021 멤브레인 Vol.31 No.3

분자각인막(MIM)은 특정 분자의 결합자리를 갖고 있는 다공성 고분자 막이다. 비용매유도 상분리(NIPS)법을 사용하여 분자각인막의 지지체로 사용될 P(AN-co-MA) 비대칭막을 제조하고, 여기에 표면 각인법을 적용하여 광활성 이니퍼터 도입과 photo-grafting을 통해 라이소자임 분자각인막을 제조하였다. P(AN-co-MA) 비대칭막을 3-chloropropyltrimethoxysilane과 광활성 이니퍼터 dithiocarbamate로 개질하고, acrylamide 단량체, N,N'-methylenebisacrylamide 가교제, 라이소자임 주형분자 혼합액을 UV 조사 환경에서 혼성중합 시켜 MIM을 제조하였다. 제조된 MIM의 FT-IR과 FE-SEM 및 EDS 분석을 실시한 결과 P(AN-co-MA) 막은 비대칭 단면 구조이었고 표면에 이니퍼터 그룹이 잘 결합되어 있어 MIM이 성공적으로 제조되었다. 제조공정의 변수 조절을 통해 라이소자임의 흡착량이 비각인막(NIM)에 비해 13배 큰 값인 2.7 mg/g을 갖는 P(AN-co-MA) 기반 MIM이 제조되었으며, 막여과 실험을 통해 라이소자임에 대한 오발부민의 투과선택도를 측정한 결과 MIM은 라이소자임의 선택적 결합력이 우수하였다. Molecularly imprinted membrane (MIM) is a porous polymer membrane incorporating with the molecular recognizing sites. In this study, the supporting P(AN-co-MA) asymmetric membrane was prepared by nonsolvent induced phase separation (NIPS) method. And then, MIM with lysozyme template sites was prepared using the surface imprinting method on the P(AN-co-MA) asymmetric membrane introducing a photoactive iniferter and then photo-grafting. The P(AN-co-MA) asymmetric membrane was modified with 3-chloropropyltrimethoxysilane and dithiocarbamate as a photoactive iniferter. To prepare a lysozyme imprinted membrane, the modified P(AN-co-MA) membrane was copolymerized with acrylamide as a functional momomer, N,N'-methylene bisacrylamide as a crosslinker and lysozyme as a template in the UV irradiation environment. The lysozyme imprinted MIM was analyzed by using SEM, FT-IR and EDS measurements. Its results confirm that all the P(AN-co-MA) membranes have an asymmetric structure and the iniferter group is successfully introduced on the membrane surface. The process parameters were adjusted to obtain MIM having the excellent lysozyme adsorption. The maximum lysozyme adsorption capacity reaches at 2.7 mg/g, which is 13 times higher than that of the non imprinted membrane (NIM). The permselective membrane filtration experiments of ovalbumin to lysozyme show that the P(AN-co-MA) MIM preferentially bounds a greater amount of lysozyme.

가중함수에 따른 능동제어 알고리듬의 비교 연구

민경원,김진구,김성춘,정란,Min, Kyung-Won,Kim, Jin-Koo,Kim, Sung-Choon,Chung, Lan 한국전산구조공학회 2001 한국전산구조공학회논문집 Vol.14 No.2

성능지수는 제어 대상이 되는 구조물의 응답과 제어기의 성능에 관한 가중함수로 구성되어 있다. 따라서 가중함수의 설계에 따라 성능지수가 변화되며 제어 효율이 달라진다. 본 논문에서는 최적 능동제어 알고리듬의 일종인 시간 영역에서의 성능지수를 고려한 LQR기법과 LQG기법 및 주파수 영역에서의 성능지수를 고려한 H₂기법에 대하여 동일한 가중함수를 적용하여 제어 성능인 제어율과 제어력을 비교하는데 목적을 두고 있다. 그러나, LQG기법은 모든 상태 변수를 알아야 하는 LQR기법의 한계를 극복할 수 있으며 LQR기법과 동일 수준의 제어율과 제어력을 보이고 있고 출력 제어라는 장점을 고려하면 현실적인 기법이라고 말할 수 있다. 마지막으로 구조물 응답과 제어기의 주파수 특성을 고려하여 주파수 필터의 가중함수를 설계하는 H₂기법을 분석하였다. H₂기법은 제어력을 저주파수 영역에 집중시킬 수 있기 때문에 구조물 응답을 효과적으로 제어할 수 있는 방법으로 분석되었다.

두개저 결손의 미세수술적 재건술

민경원,김인철,이민구,Minn, Kyung-Won,Kim, In-Chul,Lee, Min-Goo 대한미세수술학회 1999 Archives of reconstructive microsurgery Vol.8 No.1

Until recently, the cranial base tumors were deemed unresectable due to the inability to diagnose the extent of the involvement accurately and to approach and excise the tumor safely. With refinements in CT and NMR scanning and development of craniofacial techniques, reconstruction becomes absolutely crucial in allowing successful resection of these tumors. Resection of these tumors may sometimes result in massive and complex extirpation defects that are not amendable to local tissue closure. In such cases, the free tissue transfer was a useful alternative because it can provide large amount of well-vascularized tissues and reliable separation of intracranial space from bacterial flora of the upper airway. The microvascular free tissue transfer was used in 9 patients at our center to reconstruct the cranial base defects. Of these, 8 were free rectus muscle flaps, and 1 was free latissimua dorsi muscle flap. There were 1 case of partial flap loss and 1 case of postoperative wound infection. The large, complex defects were successfully reconstructed by one stage operation and the functional and aesthetic results were satisfactory with acceptable complication rates.

지진하중을 받는 단자유도 구조물의 개선된 포화 슬라이딩 모드 제어

민경원(Min Kyung-Won),이영철(Lee Young-Cheol) 대한건축학회 2003 大韓建築學會論文集 : 構造系 Vol.19 No.12

Sliding mode control(SMC) method has been investigated for control of building structures under earthquake loadings. SMC keeps responses of a structure in sliding surface in which the structure is stable. This paper presents vibration control of a structure using saturated sliding mode controller, whose maximum conrtol force is limited. The effectiveness of SMC method with controler saturation is investigated based on two performance evaluation criteria: root mean square(RMS) and maximum values of floor drifts and accelerations. Simulation results indicate that SMC method is effective in reduction of displacement and acceleration utilizing the capacity of the saturated controller efficiently.

여성기업 지원방안에 관한 연구

민경원(Min Kyung-won) 경기연구원 2014 GRI 연구논총 Vol.16 No.1

단자유도 건물의 지진응답제어를 위한 마찰감쇠기 설계

민경원(Min, Kyung-Won),성지영(Seong, Ji-Young) 한국소음진동공학회 2010 한국소음진동공학회 논문집 Vol.20 No.1

Approximate analysis for a building installed with a friction damper is performed to get insight of its dynamic behavior. Energy balance equation is used to have a closed analytical form solution of dynamic magnification factor(DMF). It is found out that DMF is dependent on friction force ratio and resonance frequency. Approximation of DMF and equivalent damping ratio of a friction damper is proposed with such assumption that the building with a friction damper shows harmonic steady-state response and narrow banded response behavior near resonance frequency. Linear transfer function from input external force to output building displacement is suggested from the simplified DMF equation. Root mean square of a building displacement is derived under earthquake-like random excitation. Finally, design procedure of a friction damper is proposed by finding friction force corresponding to target control ratio. Numerical analysis is carried out to verify the proposed design procedure.

1950년대 뮤지컬영화의 내러티브 스타일 연구

민경원(Min Kyung Won),김기용(Kim Ki Yong) 한국영화학회 2009 영화연구 Vol.0 No.41

The musical film is a phrase which indicates movie composed of songs and dance routines. The musical is a genre based on operetta of Europe, and vaudeville of America. Hence, it is intrinsically called American or Hollywood musical. As the movie changed from silent movie to sound film, the field of musical improved with the growing importance of sound, which became an important method of expression. In United States, the review format, which was represented by 〈The Broadway Melody〉(1929), and operetta style, represented by 〈The Love Parade〉(1929) showed the golden age of first generation musical films in 1930's. After the Second World War, the addition of colors and bigger scales of movies boosted the development of musical films and created original musical films with new styles, such as 〈re American In Paris〉n of1). which received the Academy Award. Also, Broadway hit musicals were made into movies, thereby becoming a more attractive factor for audiences. The musical film achieved an important position within the field of amusement movies while displaying a new and widely accepted style of expression for the contemporary. The 1950's was an era in which technological improvements brougy in confusion and changes. During the fusion process of color and black-and-white, the musical genre was the most firm movie genre to have accepted such process. The fthe most firm mo provided different visuals than ordinary movies, and displayed the charming and grangraise-en-scene which could not be experienced in performance arts. Hence, it was a period in which the movies started to gain a new style. Also, the 1950's was the time in which television sistem in America was formedn o48-52), and when the televisions were widely spread. In other words, people who had to move in order to see sights using vehicles were now able to conveniently watch televisions at home. On one hand, the survival of movies were being threatened by the appearance of televisions. On the other hand, the television was considered a means to popularize movies. In order to face such threat and change, the Hollywood started to work on sales both domestically and internationally. As the Hollywood extended its distribution network to foreign nations, various musical films entered the Korean market as well. Thus, the purpose of the present research is to investigate the unique narrative style of musical films by analyzing the narratives of famous musical films of this era. Hence, by observing the narratives and analyzing the background and scenes of 〈Singin' In The Rain〉(1952), which was a representative film of 1950's, and 〈Guys And Dolls〉(1955), it is the intention of the present paper to study the narrative style of musical films of 1950's.