• Nuclear Engineering and Technology
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• 제55권12호
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• pp.4307-4316
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• 2023

In this paper, modal effective mass for asymmetric fluid-structure interaction system is defined and equations for its calculation is derived. To establish consistency, modal effective mass in symmetric structure only system is briefly reviewed, followed by a definition of the modal effective mass in asymmetric system. The equations for calculating modal effective mass in asymmetric system are derived by utilizing the properties of left and right eigenvectors. To simplify the equations, the assumption is made that the mass matrix is only affected by the fluid. The simplified equation is then compared to the equation already used in ANSYS. Finally, the validity of the modal effective mass definition and derivation in this paper is demonstrated through a simple example.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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• pp.241-246
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• 2000

In the strut-tie model design of structural concrete, the importance of the effective strength of concrete strut has been overlooked by many practitioners. The authors believe that the effective strength of concrete strut is an important factor not only in determining steel tie forces but also in verifying the nodal zone strength and geometric compatibility condition of a selected strut-tie model. This study evaluate the effect of the effective strength of concrete strut on structural concrete design by applying the different effective strut strengths to the strut-tie model design of a post-tensioned anchorage zone and a continuous concrete deep beam.

• Steel and Composite Structures
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• 제34권3호
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• pp.453-465
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• 2020

Influences of different variables that affect the effective flexural rigidity of reinforced concrete (RC) members are not considered in the most seismic codes. Furthermore, in the last decades, the application of steel fibers in concrete matrix designs has been increased, requiring development of an accurate analytical procedure to calculate the effective flexural rigidity of steel fiber reinforced concrete (SFRC) members. In this paper, first, a nonlinear analytical procedure is proposed to calculate the SFRC members' effective flexural rigidity. The proposed model's accuracy is confirmed by comparing the results obtained from nonlinear analysis with those recorded from the experimental testing. Then a parametric study is conducted to investigate the effects of different parameters such as varying axial load and steel fiber are then investigated through moment-curvature analysis of various SFRC (normal-strength concrete) sections. The obtained results show that increasing the steel fiber volume percentage increases the effective flexural rigidity. Also it's been indicated that the varying axial load affects the effective flexural rigidity. Lastly, proper equations are developed to estimate the effective flexural rigidity of SFRC members.

• 복합신소재구조학회 논문집
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• 제6권3호
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• pp.26-31
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• 2015

The domestic and foreign specifications presented the effective width based on flange length to width ratio only. The existing paper on the effective width grasped of the effect of span, load type and cross-section properties, but localized steel bridges. Recently, The studies are going on in progress for the application of fiber reinforced composite material in construction field. Therefore, it is required to optimum design that have a good grasp the deformation characteristic of the displacements and stresses distribution and predict variation of the effective width for serviceability loading. This research addresses the effective width of all composite material box girder bridges using the finite element method. The characteristics of the effective width of composite structures may vary according to several causes, e.g., change of fibers, aspect, etc. Parametric studies were conducted to determine the effective width on the stress elastic analysis of all composite materials box bridges, with interesting observations. The various results through numerical analysis will present an important document for construct all composite material bridges.

• 대한전자공학회논문지SD
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• 제41권11호
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• pp.1-6
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• 2004

RFIC를 위한 Nanoscale MOSFET에서의 유효 게이트 저항을 직접 추출법으로 추출하여 다양한 게이트 길이에 대해 분석하였다. 추출된 유효 게이트 저항은 비교적 정확하면서 간소화된 모델을 통한 측정결과와 비교하여 10GHz 대역까지 잘 일치함을 확인하였다. 같은 공정기술로 제작된 소자들 중에서 reverse short channel 효과가 생기지 않는 긴 채널 MOSFET 소자의 경우에 일반적인 유효 게이트 저항에서와는 다른 인가전압 및 주파수 종속성을 가짐을 확인하였다. 특히, 문턱전압을 전후하여 주파수에 따라 상이한 결과를 나타내고 있으며, 게이트 인가전압이 문턱전압에 가까울 때 비이상적으로 큰 유효 게이트 저항값을 나타내었다. 이러한 특성은 직접추출법을 사용하는 RF MOSFET 모델링에 있어서 참고해야 할 중요한 특성이 될 것이다.

• 동의신경정신과학회지
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• 제17권2호
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• pp.15-36
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• 2006

Objective : This study was designed to assess effect of and Chenwangbosim-Dan(CWBSD) herbs on Mouse neuroblastoma 2a cells damaged by hypoxia-reoxygenation. Method : Mouse neuroblastoma 2a (N2a) cells were measured by MTT assay and LDH assay after 48h hypoxia and 6h reoxygenation. Mouse neuroblastoma 2a (N2a) cells were treated by CWBSD and herbs. Result : 1. In MTT assay of hypoxia CWBSD and BJI, SJH, IS, CHR, HS among all of herbs were effective. Especially CWBSD and IS were highly effective. 2. In MTT assay of reoxygenation SJI, SJH, VJ, IS, BJI were effective. Especially SJI, SJH, YJ were highly effective. 3. In LDH assay of hypoxia CWBSD, DS, DG, SJH, OMZ were effective. Especially CWBSD, DG were highly effective. 4. In LDH assay of reoxygenation all of herbs except CWBSD and BJI were generally effective. Especially CHR, SJH, YJ, OMZ, HS were highly effective. Conclusion : The results suggest that CWBSD, and it's ingradient(especially SJH, CHR and SJI) may have protective effect on condition of oxidative stress.

• 수산해양기술연구
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• 제41권3호
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• pp.227-233
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• 2005

In order to estimate the effective horse power(EHP) in towing net of a bottom trawl ship, the ship's resistance was calculated by using a series data of Yamagata and Wigley formula. Also the effective horse power for a ship(EHPs) was estimated versus the ship speed in sailing and the propulsive efficiency was calculated with the brake horse power and the effective horse power. Then the effective horse power for a ship and a trawl net were estimated in the application of the propulsive efficiency in towing net. The total effective horse power($EHP_T$) was average 187.6kW and the effective horse power for a 1.awl net($EHP_n$) was average 176.7kW at a smooth sea state in towing net. The ratio of $EHP_n$ to $EHP_T$ was about 94.0% and the value was higher slightly than was already informed at a smooth sea state. The power for keeping up a townet speed was required more about 20% of a maximum continuous power at a rather rough sea state than a smooth sea state. In the future, if the residual resistance is considered with a sea state, $EHP_n$ will be estimated more correctly Also the data of EHP estimated by this method will be used as the basic data to design a trawl net.

• International Journal of Railway
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• 제5권2호
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• pp.89-92
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• 2012

Effective notch stress, as an approach to evaluate the local stress at a notch (weld toe or root), is defined as the total stress assuming linear-elastic material behavior. This method can be effectively used to evaluate the fatigue performance of welded joints. In this study, finite element analysis results using the effective notch stress method were correlated with fatigue test results of rib-to-deck welded joints in a steel orthotropic bridge deck. Effective notch stress approach provided a good correlation with the crack pattern observed in the full-scale fatigue test. A higher effective notch stress at the critical weld toe than at the weld root was consistent with the dominant crack pattern observed at the weld toe during testing. The effective notch stress at the toe on the deck plate was about 80% higher than that on the rib; no cracks at the weld toe on the rib in the testing were observed. Maximum effective notch stress at the weld root occurred on the upper side of the root notch, which indicates that cracks are more likely to propagate into the deck plate, not into the weld metal. This is also consistent with the observed crack pattern in which the crack from the root propagated upward into the deck plate. No such crack pattern, propagating into the weld metal, was observed in the testing.

• 대한토목학회논문집
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• 제37권3호
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• pp.521-529
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• 2017

본 연구에서는 합성형교와는 다른 전단연결 상세를 가지는 콘크리트 비충전 강합성 바닥판의 유효폭을 수치적으로 분석하였다. 유효폭 산정 방법 및 위치, 작용하중 크기, 메인 베아링 바 간격-지간장비에 따른 콘크리트 비충전 강합성 바닥판의 유효폭을 평가하였다. 분석 결과 응력 형태를 사다리꼴로 이상화하여 유효폭을 산출하여도 실제 유효폭과 거의 동일한 것으로 분석되었다. 또한, 전단 강도 증가를 위해 적용된 전단홀 관통 철근이 유효폭을 증가 시키는 역할을 하는 것으로 나타났다. 메인 베아링 바 간격-지간장비에 따른 유효폭 분석 결과로부터 콘크리트 비충전강합성 바닥판의 유효폭비를 산출 할 수 있는 보정 계수를 제안하였다.

• 한방안이비인후피부과학회지
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• 제20권1호통권32호
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• pp.115-129
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• 2007

Objectives : This study was carried out to evaluate anti-oxidative, anti-microbial and anti-cancer effect for clinical application of Bibangtalmyungsan (BTS) Results : 1. The oxidative effects were measured by polyphenol, DPPH radical scavenging activity. BTS water extract was showed more effective than ethanol extract and also various solvent fractions from BTS water extract showed effective in the following order : ethyl acetate fraction > butanol fraction > hexane fraction ${\fallingdotseq}$ chloroform fraction ${\fallingdotseq}$ aqueous fraction 2. The results of anti-microbial effects were as follows. 1) Antibacterial activities of BTS extracts against Gram's negative and positive bacteria were ineffective 2) Antifungal activities of the BTS extracts against Aspergillus spp. , Trichohyton mentagrophyte KTCC 1077 were not effective. 3. The result of anti-cancer effects were as followings: 1) BTS ethanol extract was more effective than water extract against Caco-2, Calu-6, but it had cytotoxic effect against NIH3T3. 2) On the Caco-2, effective only in ethyl acetate $fraction(IC_{50}:$ 35.81 ${\mu}g/ml)$. 3) On the Calu-6, the most effective in ethyl acetate $fraction(IC_{50}:$ 189.65 ${\mu}g/ml)$ and effective In butanol $fraction(IC_{50}:$ 299.74 ${\mu}g/ml)$ and hexane $fraction(IC_{50}:$ 345.13 ${\mu}g/ml)$ 4) On the SUN-601, $IC_{50}$ value was within 80 ${\mu}g/ml$ in ethyl acetate fraction and hexane fraction. 5) On the HCT-1l6, the most effective in ethyl acetate $fraction(IC_{50}:$ 82.94 ${\mu}g/ml)$ and effective in hexane $fraction(IC_{50}:$ 374.56 ${\mu}g/ml)$. 6) On the AML-2/WT, the most effective in ethyl acetate $fraction(IC_{50}:$ 41.44 ${\mu}g/ml)$ and effective In hexane $fraction(IC_{50}:$ 303.01 ${\mu}g/ml)$. 7) On the NIH3T3, effective only in ethyl acetate $fraction(IC_{50}:$ 203.42 ${\mu}g/ml)$, but it was more ineffective than other cancer cells. Conclusion : These result suggest that BTS has antioxidative, antifungal activities and cytotoxic effects against Caco-2, Calu-6, SUN-601, HCT-116, AML-2/WT and NIH3T3, especially ethyl acetate fraction from water extract has more effective in antioxidative and anticancer effects.