• 한국전산구조공학회논문집
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• 제21권5호
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• pp.515-524
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• 2008

본 연구에서는 판 두께와 볼트 크기에 따른 고장력 볼트 마찰이음부의 극한 거동을 비선형 유한 요소 해석 및 실험을 통하여 분석하였다. 볼트의 크기 및 모재의 두께가 고장력 볼트 마찰이음부에 끼치는 영향을 미끄러짐 하중, 볼트의 변형 및 파괴하중과의 관계와 함께 파악하였다. M20, M22, M24의 세가지 볼트와 모재의 두께가 12mm, 16mm, 20mm, 30mm, 40mm인 경우에 대하여 압축력을 받는 고장력 볼트 이음부의 극한 거동을 고찰하였다. 이음부의 힘-변위 관계 및 외력-변형도 관계를 실험적으로 도출하였으며 범용 유한요소해석 프로그램인 ABAQYS를 사용한 수치해석 결과와 비교, 분석하였다.

• Food Science and Biotechnology
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• 제15권5호
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• pp.694-697
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• 2006

The initiation of immunoglobulin E (IgE)-mediated allergic reactions requires binding of IgE antibody to its high-affinity receptor. Human basophilic KU812F cells express $Fc{\varepsilon}RI$ on the cell surface and act as effector cells in the allergic response. In this study, we investigated the effects of Scutellaria radix extract on the expression of the $Fc{\varepsilon}RI$ in human KU812F cells. Flow cytometric analysis showed that S. radix extract treatment caused a concentration-dependent decrease in $Fc{\varepsilon}RI$ expression on the cell surface. Furthermore, the level of $Fc{\varepsilon}RI$ ${\alpha}$, ${\beta}$, and ${\gamma}$ chain mRNA in KU812F cells was examined by RT-PCR. S. radix extract reduced total cellular $Fc{\varepsilon}RI$ $\alpha$ and ${\gamma}$ chain mRNA expression in a concentration-dependent manner. $Fc{\varepsilon}RI$-mediated histamine release was reduced from $21.75{\pm}1.34\;ng/10^6$ cells in non-treated cells to $16.46{\pm}1.98\;ng/10^6$ cells in S. radix extract treated cells. These results suggested that S. radix extract has the potential to down-regulate of FcRI expression and to inactivate basophils.

• Animal Bioscience
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• 제35권7호
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• pp.1010-1020
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• 2022

Objective: The experiment was conducted to evaluate the effects of maternal undernutrition during late pregnancy on the expressions of genes involved in growth and development in ovine fetal perirenal brown adipose tissue (BAT). Methods: Eighteen ewes with singleton fetuses were allocated to three groups at day 90 of pregnancy: restricted group 1 (RG1, 0.33 MJ metabolisable energy [ME]/kg body weight [BW]^0.75/d, n = 6), restricted group 2 (RG2, 0.18 MJ ME/kg BW^0.75/d, n = 6), and a control group (CG, ad libitum, 0.67 MJ ME/kg BW^0.75/d, n = 6). The fetuses were removed at day 140 of pregnancy. All data were analyzed by using the analysis of variance procedure. Results: The perirenal fat weight (p = 0.0077) and perirenal fat growth rate (p = 0.0074) were reduced in RG2 compared to CG. In fetal perirenal BAT, the protein level of uncoupling protein 1 (UCP1) (p = 0.0001) was lower in RG1 and RG2 compared with CG and UCP1 mRNA expression (p = 0.0265) was decreased in RG2. The protein level of myogenic factor 5 (Myf5) was also decreased in RG2 (p = 0.0001). In addition, mRNA expressions of CyclinA (p = 0.0109), CyclinB (p = 0.0019), CyclinD (p = 0.0015), cyclin-dependent kinase 1 (CDK1) (p = 0.0001), E2F transcription factor 1 (E2F1) (p = 0.0323), E2F4 (p = 0.0101), and E2F5 (p = 0.0018) were lower in RG1 and RG2. There were decreased protein expression of peroxisome proliferator-activated receptor-γ (PPARγ) (p = 0.0043) and mRNA expression of CCAAT/enhancer-binding protein-α (C/EBPα) (p = 0.0307) in RG2 and decreased PPARγ mRNA expression (p = 0.0008) and C/EBPα protein expression (p = 0.0015) in both RG2 and RG1. Furthermore, mRNA expression of bone morphogenetic protein 4 (BMP4) (p = 0.0083) and BMP7 (p = 0.0330) decreased in RG2 and peroxisome proliferator-activated receptor co-activator-1α (PGC-1α) reduced in RG2 and RG1. Conclusion: Our observations support that repression of regulatory factors promoting differentiation and development results in the inhibition of BAT maturation in fetal perirenal fat during late pregnancy with maternal undernutrition.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.704_705
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• 2009

This paper presents a axial flux permanent magnet synchronous generator(AFPMSG), which is suitable for both vertical-axis and horizontal-axis wind turbine generation system. The design and construction features of the AFPMSG are reviewed. The characteristic analysis is performed such as cogging torque and e.m.f waveform, with the aid of a 3D finite element method. The experimental results confirm the characteristic analysis developed.

• Architectural research
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• 제3권1호
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• pp.45-52
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• 2001

In this paper, a pressurized single vertical arch and a pressurized leaning arch composed of flexible fabric material are considered. These arches have also been considered as a possible support structure for the tent-like structures. Two different boundary conditions are considered in leaning arches with fixed bases and pinned bases. The behaviors of the leaning arches are investigated for two tilt angles as 15, 30. For each angle, two loading conditions are considered as uniformly distributed load and wind loads. The F.E.M. is used through the all analysis procedures. For the results, load-deflection relationships, buckling modes, differences between two boundary conditions and deformed configurations are discussed.

• Korean Chemical Engineering Research
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• 제53권6호
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• pp.723-729
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• 2015

고성능액체크로마토그래피(high-performance liquid chromatography, HPLC)에서 C18(octadecyl silica, ODS) 칼럼에서 고리형 아데노신 일인산(cyclic adenosine monophosphate, cAMP)의 크로마토그램을 얻은 후, 모멘트 분석을 수행하였다. 일반속도 모델(general rate model, GR model)을 기반으로 first absolute moment와 second central moment를 계산하였다. 모멘트 분석의 중요한 세 가지 계수인 분자확산계수(molecular diffusivity, $D_m$), 외부물질전달계수(external mass transfer coefficient, $k_f$), 입자내부확산계수(intra-particle diffusivity, $D_e$)는 각각 Wilke-Chang 식, Wilson-Geankoplis 식을 이용하고 이론단수(theoretical plate number) 식과 van Deemter 식을 비교하여 계산하였다. 실험은 각각 세 가지의 이동상 조성, 용질 농도, 유량 조건에서 수행하였다. Van Deemter 그래프를 그려 모멘트 분석결과를 정성적으로 정리했으며, 이론단 상당높이(height equivalent to a theoretical plate, HETP, $H_{total}$)에 $H_{ax}$, $H_f$, $H_d$가 미치는 영향을 알아보기 위해 van Deemter coefficient를 비교했다. HETP에 가장 큰 영향을 주는 요인은 입자내부확산($H_d$)이었으며 외부물질 전달($H_f$)는 그 영향이 매우 작았다.

• 대한기계학회논문집A
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• 제24권9호
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• pp.2266-2273
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• 2000

Equations of motion of a multi-beam system undergoing overall rigid body motion are derived by employing finite element method. An orientation angle is employed to allow the arbitrary orientation o f the beam element. Modal coordinate reduction technique, which has been successfully utilized in the conventional linear modeling method, is employed for the present modeling method to reduce the computational effort. Different from the conventional linear modeling method, the present modeling method captures the motion-induced stiffness variations which are important for the dynamic analysis of structures undergoing overall rigid body motion. The numerical results are compared to those of a commercial program to verify the reliability of the present method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 B
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• pp.241-243
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• 2000

In this paper, we analyze three-dimensional magnetic field distribution of a convergence purity maget(C.P.M) which is used for a cathode ray tube. The magnetization vector distribution of the C.P.M is obtained from the result of magnetization process analysis using the 2D F.E.M. Then the motion of electron beam passing through the inner space of the C.P.M is determined and compared with experimental result.

• 한국환경생태학회지
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• 제35권6호
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• pp.632-643
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• 2021

본 연구는 충청북도 민주지산의 물들메나무 분포 및 식물군락구조 특성을 밝히고자 시행되었다. 민주지산 내 8개의 조사구(단위면적 400m²)를 설치하여 물들메나무 우점군락을 조사하였다. 상대우점치는 8개 군락 모두 물들메나무 (35.19%; 26.07~42.74%)가 우점하고 있어 지속적으로 세력을 유지할 것으로 판단된다. 흉고직경급별 분석 결과 물들메나무는 2~43cm까지 비교적 다양한 직경급으로 생육하고 있으며, 개체수가 많아 교란이나 급격한 환경의 변화가 발생하지 않는다면 지속적으로 세력을 유지할 것으로 판단된다. 종다양도(H')는 0.8498~1.0261, 균재도(J')는 0.8160~0.9256, 우점도(D)는 0.0789~0.1840, 최대종다양도(H'max)는 1.0414~1.2041로 분석되었다. 물들메나무의 연륜 및 생장량 분석 결과 평균 29.1년(22~58년)의 수령을 보였으며, 연평균 생장량은 군락 G가 5.84mm로 가장 높았으며, 군락 B가 2.80mm로 가장 낮았다. 유사도 분석 결과 군락 B와 E, 군락 C와 F, H 간의 유사도지수가 69.0%로 가장 높았으며, 군락 E와 F 간의 유사도지수가 29.6%로 가장 낮았다. 연구대상인 물들메나무군락지는 분포지가 매우 협소하고, 개체군 크기가 작아 산림유전자원보호지역으로 보전하는 것이 필요하다.

• 한국자동차공학회논문집
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• 제5권3호
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• pp.220-228
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• 1997

We discuss finite element approximation and use a Mindlin plate element based upon uniformly reduced numerical integration. The finite element selected for use in this work is a four-node, bilinear displacement element based upon the Mindlin theory of plates. Such elements show good accuracy for laminated composite plates when reduced numerical integration is used to evaluate the element marices. This study presents both the experimental and F.E. results for the natural frequencies of CFRPURETHANE-CFRP Composite plate. Good agreement between experimental and calculated frequencies is achived.