좁은 열린 관에 갇힌 자기 회피 고분자의 자유에너지

김국현 ( Kim Cook Hyun ),이승현 ( Lee Seung Hyun ),김주인 ( Kim Ju In ) 공군사관학교 2017 空士論文集 Vol.68 No.1

분자동역학 전산모사를 이용하여 좁은 관에 속박된 자기 회피 고분자의 자유에너지가 속박의 정도와 밀도에 따라 어떻게 주어지는지 측정하였다. 유한 크기 효과(finite size effect)를 고려한 밀도 □와 양 끝이 열린 원기둥 속박하의 고분자의 자유에너지 F_cyl의 관계는 농축영역(concentrated regime)에서 F_cyl~N□^1.3로서 기존의 이론 분석 F_cyl~N□^1.77과 차이를 보이며, 구형 속박에서의 자유에너지 F_sphere~ N□^1.97과도 다르다. 이 때문에 구형 속박하의 고분자는 원기둥에 속박된 고분자로 환산하여 생각할 경우, 닫힌 원기둥의 경우를 고려해야 한다. We study the free energy of a self-avoiding flexible polymer in an open cylindrical confinement through molecular dynamics simulation. In the concentrated regime, the free energy F_cyl of a flexible polymer in a open narrow cylinder is measured and related to the density □ by F_cyl~ N□^1.3, considering a finite size effect of a monomer in calculation of the density. This result is different from the former theoretical free energy F_cyl~N□^1.77 but also the free energy of a polymer in a spherical confinement F_sphere~ N□^1.97 measured in molecular dynamics simulation. This means a polymer in a sphere in concentrated regime should be mapped to a polymer in a closed cylinder.

특발성 염증성 근육병증에서 Toll-Like Receptor의 발현

김근태 ( Geun Tae Kim ),이준희 ( Jun Hee Lee ),백승훈 ( Seung Hoon Paek ),이정욱 ( Joung Wook Lee ),조미라 ( Mi Ra Cho ),김주인 ( Ju In Kim ),이선희 ( Sun Hee Lee ),김대성 ( Dae Seong Kim ),김성일 ( Sung Il Kim ) 대한류마티스학회 2007 대한류마티스학회지 Vol.14 No.2

Objective: To investigate the expression of toll-like receptor (TLR)-2, 4 and 9 in idiopathic inflammatory myopathies (IIMs). Methods: The expression of TLR-2, 4 and 9 was measured by real-time RT-PCR and immunohistochemical stain (IHS) from muscle tissues in patients with IIMs and controls. Results: The expression levels of TLR-2, 4 and 9 in IIMs were significantly higher than controls. TLR-2, 4 and 9 were mainly expressed on sarcolemma of muscle fibers, perimysial vascular endothelium and infiltrating inflammatory cells in dermatomyositis, whereas, they were mainly expressed on sarcolemma of muscle fibers, destructed muscle fibers, and enodmysial infiltrating inflammatory cells in polymyositis. Conclusion: TLR-2, 4 and 9 were highly expressed in muscle tissue of IIMs. These results suggest that TLR-2, 4 and 9 play a role in pathogenesis of IIMs.

류마티스 관절염 동물 모델에서 활막의 RANKL/OPG mRNA 발현 비율 및 IL-17의 효과

이준희 ( Jun Hee Lee ),김근태 ( Geun Tae Kim ),류선 ( Sun Ryu ),김주인 ( Ju In Kim ),백승훈 ( Seung Hoon Baek ),김성일 ( Sung Il Kim ) 대한류마티스학회 2006 대한류마티스학회지 Vol.13 No.2

Objective: To investigate the synovial mRNA expression of receptor activator of NFκB (RANK), RANK ligand (RANKL), osteoprotegerin (OPG) and RANKL/OPG mRNA expression ratio, and to evaluate the effects of IL-17 in experimental rheumatoid arthritis (RA) model. Methods: After induction of collagen-induced arthritis (CIA) by type II collagen in DBA1 mice, mice were anesthetized at day 28 and a small aperture in the skin of the knee was performed. Mice, in which arthritis of knee was present, were selected and divided into 3 groups, and phosphate-buffered saline (PBS group), IL-17 (IL-17 group) or anti-IL-17 monoclonal antibody (anti-IL-17 group) was injected to both knee joint at day 28 and 32. At day 35, mice were sacrificed and synovium of knee joints were isolated. Synovial mRNA expression of RANKL, RANK and OPG was assessed by real-time RT-PCR and immunohistochemical stain. Results: Synovial RANKL and RANK mRNA expressions were significantly different among IL-17, PBS, anti-IL-17 and normal group (IL-17>PBS>anti-IL-17>normal group), and synovial OPG mRNA expressions in PBS, IL-17 and anti-IL-17 group were significantly high than those in normal group, however, there was no significant difference among IL-17, PBS and anti-IL-17 group. RANKL/OPG mRNA ratio was significantly different among these groups (IL-17>PBS>anti-IL-17>normal group). In immunohistochemical stain, RANKL, RANK and OPG-positive cells were expressed at synovium. Conclusion: Synovial RANKL/OPG mRNA ratio was enhanced in CIA, and IL-17 induced higher RANKL/OPG ratio in the synovium of CIA, which was blocked by anti-IL-17 antibody. These results suggest that RANKL/OPG mRNA ratio play an important roles on bone destruction, and IL-17 may be actively involved in bone destruction by enhancing RANKL/OPG ratio in CIA model.

중심축 하중을 받는 냉각성형 각형강관 부재의 내력 및 변형능력에 관한 실험적 연구

김주인(Ju In Kim),김진평(Jin Pyung Kim),서정환(Jeong Hwan Seo),양영성(Young Sung Yang) 한국강구조학회 1996 韓國鋼構造學會誌 Vol.8 No.2

This paper is an experimental study to research the maximum strength and deformation capacity of the cold-formed square tubular members under compression. On short and long columns, yield strength, maximum strength and deformation capacity have particular relation d/t ratio and slenderness. In this study, through compression test of short and long columns concerning d/t ratio, we investigated the local buckling strength, yield strength, maximum strength and plastic deformation capacity of members.

풍력터빈 날개 주위의 점성유동장 해석

김주인(Ju-In Kim),김우전(Wu-Joan Kim) 한국해양환경·에너지학회 2011 한국해양환경공학회 학술대회논문집 Vol.2011 No.11

최근 관심이 높아지고 있는 해상풍력 터빈의 성능평가를 위해 풍력터빈 날개에 대한 점성 유동장 해석을 수행하였다. Fluent package를 사용하여 회전하는 비관성 좌표계에서 Reynolds-averaged Navier-Stokes 방정식의 해를 구하였다. 난류 모형은 realizable k-ε model을 사용하였으며, 격자계는 구조 격자계와 비구조 격자계를 혼합하여 사용하였다. 먼저 실험값이 공개되어 있는 2차원 날개에 대한 유동해석을 통해 수치계산 결과를 검증하였다. 다음으로 NACA 4-series 단면을 가지는 세 개의 날개가 2 MW의 정격출력을 내도록 설계된 풍력터빈 날개를 대상으로 회전수와 피치각을 고정시킨 상태에서 입사류의 속도를 변화하여 각 TSR 별로 성능해석을 수행하였다. 그리고 풍력터빈의 성능향상을 위해 날개의 끝에 세 가지 형태의 end plate를 붙여 성능 변화를 추정하였다. 그 중에서 날개의 suction side에 end plate를 붙인 경우가 가장 우수한 성능을 보였다. Turbulent flow analysis around a wind turbine blade was performed to evaluate the power performance of offshore wind turbine. Fluent package was utilized to solve the Reynolds-averaged Navier-Stokes equations in non-inertial rotating coordinates. The realizable k-ε model was used for turbulence closure and the grid system combining structured and unstructured grids was generated. In the first, lift and drag forces of 2-D foil section were calculated and compared with existing experimental data for the validation. Then torque and thrust of the wind turbine blade having NACA 4-series sections were calculated with fixed pitch angle and rpm. Tip speed ratio was varied by changing wind speed. In the last three kinds of end plate were attached at the tip of the blade to enhance the performance of wind turbine. Among them the end plate attached at the suction side of the blade was found to be most effective.

풍력터빈 날개의 끝판과 레이크 효과에 대한 점성유동장 해석

김주인(Ju-In Kim),김우전(Wu-Joan Kim) 한국해양환경·에너지학회 2011 한국해양환경·에너지학회지 Vol.14 No.4

AT Model의 1차 상전이에 대한 해석적 연구

김주인 ( Kim Ju In ),원기탁 ( Won Ki Tak ),김국현 ( Kim Cook Hyun ) 공군사관학교 2017 空士論文集 Vol.68 No.1

AT Model(Ashkin-Teller Model)은 위상구조(Network에 포함된 Node와 서로 다른 두 Node를 연결한 Link(Edge)의 전체 집합)가 동일한 서로 다른 두 Network 사이에서 일대일 대응을 이루는 Link 쌍을 통해 Spin 상호작용이 작용하는 모형이다. AT Model은 일대일 대응을 이루는 한 쌍의 Link 간 Spin 상호작용의 세기에 따라 Spin 상호작용의 세기가 작을 때는 2차 상전이가, 클 때는 1차 상전이가 나타나는 것이 전산모사를 통해 관찰로 잘 알려져 있다.[1] 본 논문에서는 두 Network 사이의 Spin 상호작용이 상당히 강할 때 1차 상전이가 발생한다는 사실을 해석적 접근을 통해 밝혔다. 본 논문에서의 해석적 방법론은 다른 Model에서의 1차 상전이의 해석적 연구에 적용 가능할 것으로 기대된다. AT Model(Ashkin-Teller Model) is a model that has spin interaction between a pair of link belonging to two different networks with same topology structure. Types of the phase transition in the AT model can be changed by strength of the link interaction between two different network. It is well known numerically that the second phase transition appears when the spin interaction is weak while the first phase transition appears when the spin interaction is strong enough.[1] In this paper, We study the condition of the first order phase transition by analytic method. We also expect that we can understand the first order phase transition in other models in the way which is given by this paper.

아스팔트 콘크리트에 적정 폐비닐 첨가량 결정에 관한 실험적 연구

김광우 ( Kim Kwang Woo ),김주인 ( Kim Ju In ),이순제 ( Lee Soon Jae ),최선주 ( Choi Sun Ju ) 한국농공학회 2002 韓國農工學會誌 : 전원과 자원 Vol.44 No.5

This study is a fundamental research for recycling waste vinyl (WV) in asphalt mixture for improving roadway pavement. Mix design was conducted by WV content and optimum asphalt content (OAC) was determined for dense-graded surface course mixture. Marshall stability test, indirect tensile strength (ITS) test and wheel tracking test were carried out to measure the characteristics of WV-added asphalt concretes. From the results of this study, recycling WV in asphalt mixture is possible. However, as WV content increased, melted WV clustering appeared in asphalt mixture. It could be considered that adding too much WV in asphalt mixture is not proper. The proper content of LDPE and HDPE WV was appeared to be 12% and 8%, respectively.

특발성 염증성 근육병증 환자에서 IL-17 발현의 증가

백승훈 ( Seung Hoon Baek ),이준희 ( Jun Hee Lee ),김근태 ( Geun Tae Kim ),이정욱 ( Joung Wook Lee ),조미라 ( Mi Ra Cho ),김주인 ( Ju In Kim ),이선희 ( Sun Hee Lee ),김대성 ( Dae Seong Kim ),김성일 ( Sung Il Kim ) 대한류마티스학회 2008 대한류마티스학회지 Vol.15 No.2

Objective: Idiopathic inflammatory myopathies (IIMs) are systemic autoimmune diseases characterized by infiltration of T lymphocytes, monocytes, and macrophages in muscle tissues. Interleukin-17 (IL-17), a Th17 cytokine, has potent pro-inflammatory actions and plays a role in autoimmune diseases. We investigated the expression of IL-17 in muscle tissues of patients with IIMs. Methods: We measured the IL-17 mRNA level of muscle tissues from 14 patients with IIMs (9 patients with dermatomyositis and 5 patients with polymyositis) by real-time RT-PCR and compared with controls. We also performed an immunohistochemical stain to detect IL-17 expression. Results: The expressions of IL-17 were significantly enhanced in IIMs than controls. In immunohistochemistry, IL-17 was expressed in perimysial, endomysial and perivascular infiltrating inflammatory cells. Conclusion: These results suggest that IL-17 plays a role in the immunopathogenesis of IIMs.

Numerical Study on Wave Loads and Dynamic Responses of Fixed Type Offshore Wind Turbine Substructures

박연석(Yeon-Seok Park),김주인(Ju-In Kim),김진성(Jin-Sung Kim),송창용(Chang-Yong Song),김우전(Wu-Joan Kim),이대용(Dae-Yong Lee) 한국해양환경·에너지학회 2012 한국해양환경공학회 학술대회논문집 Vol.2012 No.11

본 연구에서는 고정식 해상풍력하부구조물로 사용되는 Mono-pile, Jacket, Dolphin 그리고 중력식 구조물에 작용하는 파랑하중 산정 및 동적응답 특성을 분석하기 위하여 수치계산을 수행하였다. 먼저, 상용 CFD 소프트웨어인 Fluent를 사용하여 구현된 수치조파수조에서 구조물에 작용하는 파랑하중을 산정하였다. 수면관통 면적이 파랑하중의 크기에 직접적인 형상요소임을 확인하였다. 다음으로 구조해석 프로그램인 ANSYS-ASAS를 통해 각각의 구조물에 파랑조건을 적용하여 동적하중 응답특성을 살펴보았다. 본 논문에서 검토된 구조물 중에서는 파랑하중과 구조응답의 관점에서 Jacket이 가장 유리한 구조물로 평가되었다. This paper presents a series of numerical studies for the evaluation of dynamic responses of fixed type offshore wind turbine substructures such as mono-pile, gravity based structure (GBS), jacket, and multi-piles (dolphin). In the first CFD simulations using Fluent package were carried out to evaluate wave loads on various fixed type OWT substructures with the design wave condition for the west-south region of Korea. Numerical wave tank (NWT) based on computational fluid dynamics (CFD) was adopted to generate a progressive regular wave using a piston type wave maker. It was found that the water-piercing area of piles of the substructure is a key parameter determining the wave load exerted in horizontal direction. In the next the dynamic structural responses of substructure elements under the wave load were calculated using finite element method (FEM). ANSYS-ASAS package was utilized to calculate structural responses when wave load on each element was determined by Morison’s formula. The paper numerically identifies dynamic response characteristics of various fixed type offshore wind substructures. It is likely that the jacket is the most appropriate type among the substructures considered in this paper.