• 한국지진공학회논문집
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• 제25권6호
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• pp.305-314
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• 2021

The Gyeongju and Pohang earthquakes caused damages to many cultural properties; particularly, stone pagoda structures were significantly damaged among masonry cultural properties. To preserve these structures, it is necessary to understand their dynamic behavior characteristics under earthquakes. Analyses on such areas as deformation, frequency, maximum acceleration, permanent displacement, sliding, and rocking have to be performed. Although many analytical studies have already been conducted, dynamic behavior studies based on experiments are insufficient. Therefore, this study analyzed dynamic behavior characteristics by performing a shaking table experiment on a three-story stone pagoda structure at the Cheollongsa temple site damaged by the Gyeongju earthquake. As a result of the experiment, the displacements of stylobates did not occur significantly, but the tower body parts rotated. In particular, the rotation of the 1F main body stone was relatively larger than that of the other chief body stones because the 1F main body stone is relatively more slender than the other parts. In addition, the decorative top was identified as the component most vulnerable to sliding. This study found that the 1F main body stone is vulnerable to rocking, and the parts located on the upper part are more vulnerable to sliding.

• 영어영문학
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• 제54권4호
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• pp.443-459
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• 2008

This paper examines the discourse of masturbation in modern England and aims to re-draw the map of male sexuality related to such issues as nation, empire, family, and economy. It argues that the discourse of masturbation in modern England reflects national anxieties for the future of empire and an economic concern for unproductive sexual behavior, which were the main factors to transform masturbation into "solitary vice." The anxieties about empire and British dominance were constituted as the core of the anti-masturbation discourse on the boys. The imperial destiny was regarded to depend on the protection of the middle- and upper-class boys from the harmful psychological and physiological effects of masturbation represented in Lawrence's "The Rocking-Horse Winner." In the case of a single male, the concern for masturbation is constructed as a concern about economy, family, and human solidarity. As seen in Eliot's Silas Marner, the act of masturbation was condemned as the fulfillment of illegitimate sexual desire outside the familial sphere and a commercial economy, and thus without the possibility of human community. Silas Marner and Meredith's The Ordeal of Richard Feverel show the ways of reconstituting sexual others as normalized subjects: Boys were forced to be asexual through the regime of surveillance; and a single male was required to enroll in a remedial course on familial respectability.

• Journal of Microbiology and Biotechnology
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• 제23권9호
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• pp.1308-1321
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• 2013

The emergence of microcarrier technology has brought a renewed interest in anchorage-dependent cell culture for high-yield processes. Well-known in vaccine production, microcarrier culture also has potential for application in other fields. In this work, two types of microcarriers were evaluated for small-scale monoclonal antibody (mAb) production by CHO-K1 cells. Cultures (5 ml) of microporous Cytodex 3 and macroporous CultiSpher-S carriers were performed in vented conical tubes and subsequently scaled-up (20 ml) to shake-flasks, testing combinations of different culture conditions (cell concentration, microcarrier concentration, rocking methodology, rocking speed, and initial culture volume). Culture performance was evaluated by considering the mAb production and cell growth at the phases of initial adhesion and proliferation. The best culture performances were obtained with Cytodex 3, regarding cell proliferation (average $1.85{\pm}0.11{\times}10^6$ cells/ml against $0.60{\pm}0.08{\times}10^6$ cells/ml for CultiSpher-S), mAb production ($2.04{\pm}0.41{\mu}g/ml$ against $0.99{\pm}0.35{\mu}g/ml$ for CultiSpher-S), and culture longevity (30 days against 10-15 days for CultiSpher-S), probably due to the collagen-coated dextran matrix that potentiates adhesion and prevents detachment. The culture conditions of greater influence were rocking mechanism (Cytodex 3, pulse followed by continuous) and initial cell concentration (CultiSpher-S, $4{\times}10^5$ cells/ml). Microcarriers proved to be a viable and favorable alternative to standard adherent and suspended cultures for mAb production by CHO-K1 cells, with simple operation, easy scale-up, and significantly higher levels of mAb production. However, variations of microcarrier culture performance in different vessels reiterate the need for optimization at each step of the scale-up process.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1999년도 제17회 학술발표회 논문개요집
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• pp.117-117
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• 1999

최근 광소자와 더불어 발전과 더불어 고효율의 새로운 광소자에 대한 수요가 증가되고 있다. ZnO는 이러한 특성을 가진 재료중에 한가지로서 최근 들어 그 가능성에 대한 연구가 활발히 이루어지고 있다. 특히 상온에서 exciton binding energy가 다른 재료보다 큰 60meV로 고효율의 blue, UV 발광이 가능한 재료로 알려져 있다. 본 연구에서도 광소자로서 ZnO를 활용하기 위해서 RF magnetron sputtering법을 이용하기 위하여 광특성의 향상에 목적을 두고 연구하였다. ZnO 박막은 RF magnetron sputtering법을 이용하여 sapphire (0001) 기판위에 성장시켰다. RF power는 60W에서 120W까지 변화시켰고 박막의 성장온도는 55$0^{\circ}C$와 $600^{\circ}C$로 변화시켰으며, 박막의 성장시간은 60분, ZnO target과 기판과의 거리는 4.5cm로 하여 성장시켰다. 성장된 ZnO 박막은 XRD $\theta$-rocking scan 측정을 통해서 박막의 C-축 배향성과 RBS channeling를 이용하여 ZnO 박막의 epitaxial 성장 정도를 측정하였다. 박막의 상온 발광 특성은 He-Cd laser를 사용한 photoluminescence spectra로 측정하였다. 또한 표면의 morphology는 atomic force microscope(AFM)를 이용하여 관찰하였으며 transmission electron microscopy(TEM)을 사용하여 ZnO박막의 단면적을 관찰함으로서 grain의 성장과 광특성 및 결정성과의 영향에 대해서 연구하였다. ZnO 박막의 성장온도 55$0^{\circ}C$에서 RF power를 60W에서 120W까지 변화시킬 경우 XRD $\theta$-rocking peak의 반치폭이 0.157$^{\circ}$에서 0.436$^{\circ}$까지 변화하였고 80W에서 최소값을 가졌으며 in-plain에 대한 XRD 측정 결과 ZnO 박막의 성장은 sapphire 기판에 대해서 30$^{\circ}$회전되어 성장된 것으로 알 수 있었으며 이는 ZnO [100]∥ Al2O3[110]의 관계를 갖는다는 것을 나타낸다. 광특성의 측정 결과인 PL peak의 반치폭은 133.67meV에서 89.5meV까지 변화함을 알 수 있었고 80W에서 최대값을 가졌으며 이는 RF power의 변화에 따른 결정성의 변화와는 반대되는 현상임을 알 수 있었다. 그러나 성장온도 $600^{\circ}C$일때에는 XRD $\theta$-rocking peak의 반치폭이 0.129$^{\circ}$로 결정성이 우수한 박막임을 확인할 수 있었고 PL peak의 반치폭 또한 Ar과 O2의 비율에 따라 76.32meV에서 98.77meV로 광특성도 우수한 것으로 나타났다. RBS channeling 결과 55$0^{\circ}C$에서는 $\chi$min값이 50~60%였으나 $600^{\circ}C$일 때에는 $\chi$min값이 4~5%로 박막이 epitaxial 성장을 하였다는 것을 알 수 있었다. 결정성과 광특성과의 연관성을 알아보기 위해 TEM을 이용한 박막의 cross section image를 관찰한 결과 광특성이 우수한 시편일수록 grain의 크기가 큰 것으로 나타났고 결정성이 우수한 시편의 경우에서는 XRD분석 결과에서처럼 C-축배향성이 우수한 것을 확인할 수 있었다. 이상의 결과로부터 RF magnetron sputtering 법으로 광특성이 우수한 양질의 ZnO박막 성장이 가능하였다는 것을 알 수 있었으며 광소자로써의 가능성을 확인 할 수 있었다.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2000년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Spring
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• pp.298-307
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• 2000

The behavior of a unreinforced cement brick building structure subjected to earthquake loading was experimentally investigated. for this four full size wall specimens were tested under quasi-static in-plane cyclic loading. Experimental observations indicate that the failure modes of unreinforced masonry walls are principally governed by sliding or/and rocking depending on the aspect ration and magnitude of axial loading. Also found was the flexure or shear mode resulting from the degraded strength of brick and/or mortar due to the cyclic loading effect.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.1130-1135
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• 2001

This paper investigated the dynamic performance of HDD disk-spindle system to reduce disk fluttering. Rocking frequencies of the disk-spindle system and radial NRRO are measured to escape the ball defect frequencies and to determine the relative optimal position of the disk in the motor. It was found that disk fluttering was reduced by increasing disk thickness, inserting viscoelastic material between the disk and the spacer and decreasing the gap between the disk and the base.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1993년도 봄 학술발표회논문집
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• pp.191-198
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• 1993

This paper presents the analysis briefs to evaluate the structural adequacy of the KMRR spent fuel storage racks which stack modules in three layers. The seismic analysis models are idealized to consider the overall dynamic motions such as rocking, sliding and liftoff in the event of an postulated earthquake. The displacement time histories of the floor obtained from the floor response spectra in three orthogonal directions are simultaneously applied to the nonlinear seismic model of the structure with gap and friction elements.

• Smart Structures and Systems
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• 제2권4호
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• pp.313-320
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• 2006

The reliability analysis of structures subjected to stochastic loading involves evaluation of time and probability of the system's residence in a reference domain. In this paper, we derive an asymptotic estimate of exit time for multi-degrees-of-freedom structural systems. The system's dynamics is governed by the Lagrangian equations with linear dissipation and fast additive noise. The logarithmic asymptotic of exit time is found explicitly as a sum of two terms dependent on kinetic and potential energy of the system, respectively. As an example, we estimate exit time and an associated structural performance for a rocking structure.

• Structural Engineering and Mechanics
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• 제40권6호
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• pp.763-782
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• 2011

Results from nonlinear time-history analyses of wall-frame structural models indicate that the condition of vulnerable foundations -for which uplifting and reaching the bearing capacity of the supporting soil can occur before yielding at the base of the shear walls- may not be necessarily detrimental to the drift response of buildings under strong ground motions. Analyses also show that a soil-foundation system can inherently have deformation capacity well in excess of the demand and thus act as a source of energy dissipation that protects the structural integrity of the shear walls.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.69-72
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• 2006

The objective of this study is to find out the shear capacity of URM wall and the variables that affect the shear capacity of URM wall such as the opening and the aspect ratio, considering four kinds of failure modes, sliding shear failure, toe crushing failure, and diagonal shear failure. The main varialble is the shape of opening of URM walls. First URM has one door, second has one window, third hase one door and one window, the last has two windows. The test results of URM with openings show that the specimens are governed by rocking failure mode.