• Structural Engineering and Mechanics
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• 제21권1호
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• pp.1-18
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• 2005

Foschi's connector model is used as a basic component in the development of nonlinear analysis programs for timber structures. This paper presents the extension of the model to include the effect of shaft frictional forces. The wood medium is modeled using the Foschi embedment model, while shaft friction is modeled using an elastic Coulomb-type friction model. The initial confining pressure for the case of driven fasteners is accounted for by a lateral shift of the load-embedment curve. The model is used to compute the cyclic response of both driven and inserted fasteners. The results obtained from the cases studied indicate that initial confining pressure and friction do not have a significant effect on the computed hysteretic response, however, they significantly affect the computed amount of fastener withdrawal. This model is particularly well-suited for modeling the hysteretic response of shear walls with moderate fastener withdrawal under lateral cyclic or earthquake loading.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2004년도 가을 학술발표회 논문집
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• pp.484-491
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• 2004

In this study, the effect of the Near Fault Ground Motion which hasn't been considered at the domestic seismic design is demonstrated through the seismic response analysis of suspension bridge. After selecting the typical Near and Far Fault Ground Motion, the response characteristics are analysed by conducting the seismic response analysis about the long period suspension bridge which is expected to suffer the effect of Near Fault Ground Motions more largely. According to the results of this study, the Near Fault Ground Motions affect the suspension bridge more considerably than the Far Fault Ground Motions.

• Interaction and multiscale mechanics
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• 제2권3호
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• pp.263-276
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• 2009

This paper is intended to investigate interaction response of a train running over a suspension bridge undergoing support settlements. The suspension bridge is modeled as a single-span suspended beam with hinged ends and the train as successive moving oscillators with identical properties. To conduct this dynamic problem with non-homogeneous boundary conditions, this study first divides the total response of the suspended beam into two parts: the static and dynamic responses. Then, the coupled equations of motion for the suspended beam carrying multiple moving oscillators are transformed into a set of nonlinearly coupled generalized equations by Galerkin's method, and solved using the Newmark method with an incremental-iterative procedure including the three phases: predictor, corrector, and equilibrium-checking. Numerical investigations demonstrate that the present iterative technique is available in dealing with the dynamic interaction problem of vehicle/bridge coupling system and that the differential movements of bridge supports will significantly affect the dynamic response of the running vehicles but insignificant influence on the bridge response.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2008년도 정기총회 및 학술발표대회
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• pp.123-126
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• 2008

This research develops a methodology for standard design of spatial Database utilizing the disaster ethnography. Especially, the disaster response operation is sensitive to the size of the disaster, location, damage situation, resource a variability, etc. Moreover, there are many unknown and unexpected factors that will affect the disaster response strategy. But, the future Crisis Management Systems is needed that past disaster teaching. In another words, from now on the response systems need to prepare several scenarios and spatial data and manual etc. before the disaster. Then, this research is the experimental research which examined the relationship between the disaster-ethnography and the GIS spatial data of disaster.

• 한국철도학회논문집
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• 제14권2호
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• pp.160-166
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• 2011

열차하중에 의한 토공노반의 동적응답은 다양한 주변환경에 종속적이기 때문에 정확한 특성을 규명하는 것은 어렵다. 그러나 일부 궤도틀림의 원인이 노반의 불균일한 지지력과 이에 따른 동적 응답의 영향일 것으로 예상되기 때문에 다양한 궤도틀림원인 분석 및 대책에 대한 연구를 위해서는 노반의 동적응답에 대한 연구가 필요하다. 본 논문에서는 노반의 동적응답이 궤도변형에 미치는 영향을 분석하기 위한 기초연구로서 여러가지 영향조건 중 노반의 구조와 재료강성의 변화에 따른 노반의 탁월 주파수와 진동에너지의 크기에 대한 응답을 검토하였다. 검토단면은 탁월대역의 에너지 증폭이 쉬운 이 층노반구조로서 노반과 연암으로 구성하였다. 검토내용은 각 조건별 파의 전파특성을 규명하고 노반의 동적응답을 이론적, 해석적, 경험적 방법으로 비교 검토하여 궤도틀림에 미치는 영향을 평가하였다.

• 한국운동역학회지
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• 제24권4호
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• pp.367-373
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• 2014

Most athletes execute rhythmic hop as a preparatory motion in Taekwondo sparring. The purpose of this study was to investigate the effect of rhythmic hop on the response times and kicking velocities of Taekwondo kicks. Twelve male elite Taekwondo athletes performed a roundhouse kick and a back kick as fast as possible immediately after seeing an external stimulus in rhythmic hop and in no hop, respectively. The three-dimensional marker data of the whole body were measured at sampling rate of 200 Hz. Paired t-tests were used to compare dependent measures between hop and no hop conditions. Results indicated that the rhythmic hop did not affect response time statistically but improved the kicking velocity significantly than no hop did. Different instants of detecting an external stimulus in rhythmic hop for the back kick showed significantly different response times. Conclusively, rhythmic hop is recommendable for the purpose of kicking velocity, but not for the purpose of response time. Athletes should be careful in executing rhythmic hop as their preparatory motions for the back kick, since the response time could be shortened or lengthened according to the instant of detecting an external stimulus.

• Steel and Composite Structures
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• 제36권1호
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• pp.17-29
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• 2020

This paper presents experimental and numerical studies on the seismic responses of the steel cabinet facility considering the nonlinear behavior of connections and site-response effects. Three finite element (FE) models with differences of type and number of connections between steel plates and frame members have been developed to demonstrate adequately dynamic responses of structures. The screw connections with the bilinear force-deformation relationship are proposed to represent the inelastic behavior of the cabinet. The experiment is carried out to provide a verification with improved FE models. It shows that the natural frequencies of the cabinet are sensitive to the plate and frame connectors. The screw connections reduce the free vibration compared to the weld one, with decreased values of 2.82% and 4.87% corresponding to front-to-back and side-to-side directions. Additionally, the seismic responses are investigated for various geological configurations. Input time histories are generated so that their response spectrums are compatible with a required response spectrum via the time-domain spectral matching. The results indicate that both site effects and nonlinear behavior of connections affect greatly on the seismic response of structures.

• Journal of Information Processing Systems
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• 제20권3호
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• pp.345-359
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• 2024

A regression model represents the relationship between explanatory and response variables. In real life, explanatory variables often affect a response variable with a certain time lag, rather than immediately. For example, the marriage rate affects the birth rate with a time lag of 1 to 2 years. Although deep learning models have been successfully used to model various relationships, most of them do not consider the time lags between explanatory and response variables. Therefore, in this paper, we propose an extension of deep learning models, which automatically finds the time lags between explanatory and response variables. The proposed method finds out which of the past values of the explanatory variables minimize the error of the model, and uses the found values to determine the time lag between each explanatory variable and response variables. After determining the time lags between explanatory and response variables, the proposed method trains the deep learning model again by reflecting these time lags. Through various experiments applying the proposed method to a few deep learning models, we confirm that the proposed method can find a more accurate model whose error is reduced by more than 60% compared to the original model.

• 대한한방소아과학회지
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• 제8권1호
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• pp.39-58
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• 1994

Even though appropriate immune response is necessary for the survival of the individual, excessive or insufficient immune response might cause autoimmune or allergic disease respectively. So the immune response must be controlled to the degree that is beneficial for the well being of the individual. This study was undertaken to know the effects of Junsibaekchulsan(JB) on the immune system od the mouse. For the evalulation of the cell-mediated immunity(CMI), delayed-type hypersensitivity against dinitrofluorobenzene(DNFB) were measured, and humoral immunity, hemagglutinin and hemolysin titers against SRBCs(sheep red blood cells) were measured, and rosette formation of spleen cells with SRBCs were measured. For the evaluation of innate immunity, phagocytic activity of macrophages, natural killer cell activity, and reactive nitrogen and oxygen intermediates were measured. The results are as follows: 1. The administration of JB depressed the antibody formation (hemagglutinin and hemolysin) against SRBCs. 2. The administration of JB did not affect the delayed-type hypersensitivity against DNFB. 3. The administration of JB did not affect the cytotoxic activity of natural killer cells. 4. The administration of JB increased the phagocytic activity of macrophages. 5. The administration of JB increased the rosette formating cells of the spleen cells. 6. The exposure of JB induced the secretion of reactive nitrogen intermediates but administration of JB deperssed the production of reactive oxygen intermediates. Administration of JB selectively depressed the humoral immune response without affecting CMI and innate immunity. These results of JB on the immune system might be useful for the treatment of such.

• Journal of Radiation Protection and Research
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• 제21권4호
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• pp.285-296
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• 1996

NaI(T1) 섬광검출기를 이용하여 감마선원인 Cr-51, Cs-137, Mn-54, Zn-65에 대하여 공기와 깊이가 다른 수중에서 에너지스펙트럼을 조사하였다. 측정한 스펙트럼의 차이와 변화를 정량적으로 비교분석하기 위해서 측정 스펙트럼을 곡선근사할 수 있는 응답함수를 구성하였다. 본 연구에서 밝혀진 바에 의하면 구성된 응답함수는 공기 중 뿐만 아니라 수중에서 측정된 스펙트럼을 거의 완전하게 나타낼 수 있었다. 또한 응답함수에 사용된 계수들을 비교함으로써 공기와 수중에서-물의 깊이에 따른-스펙트럼의 특성 면화를 정량적으로 규정할 수 있었다. 응답함수의 계수 가운데 전에너지 봉우리의 높이 및 비율이 물의 깊이에 가장 민감하게 영향을 받았으며, 그 외에도 전에너지 봉우리의 퍼진 정도, flat continuum의 높이, 1차 콤프턴산란 연속의 높이, Compton edge의 모양을 나타내는 응답함수계수 등에서 미약하나마 물의 깊이에 따라 변화를 보였다.