• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.6
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• pp.591-599
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• 2011

This study investigates influencing factors on numerical crash simulation between RC slab and soft projectile using explicit dynamic method. Considered experimental test is the MEPPEN II/4 test, which has been conducted at the end of the years 70' in Germany as one of the numerous experimental test related to design of nuclear power plants. LS-DYNA software is adopted for numerical study, and influencing factors such as constitutive model of concrete, strain rate effect of steel and concrete, support modeling method, etc. are investigated. More reasonable simulation results can be achieved through appropriate consideration of these factors, especially of constitutive model of concrete material since this factor affects most among the investigated factors.

• Proceeding of KASS Symposium
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• 2006.05a
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• pp.246-255
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• 2006

In these days the floor vibration is beginning to make its appearance of the environmental dispute in apartment building. Standard floor system are suggested for the settlement of this issue by government. The sound of floor impact sound is needed to secure comfortable quality in housing. Also, it is required an accurate analysis and a proper evaluation for floor vibration. Refine model is necessary for the floor system of housing to analyze accurately the floor vibration. But this refine model is not efficient because it is required so much running time for vibration analysis and it is difficult of modeling of standard floor slab. In this paper, new modeling methods of standard floor slab are proposed for the accurate rigidity evaluation. By using the new modeling method, the accurate vibration response can be obtained and can accurately evaluate the rigidity of standard floor system with resilient materials. Therefore the proposed modeling method is of practical use for vibration analysis of floor system of apartment building.

• Computers and Concrete
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• v.33 no.6
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• pp.689-706
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• 2024

This study is aimed at identifying structural element stiffness influence on vertical earthquake response of mid-rise R/C frame buildings. To this aim, a mid-rise RC building structure is designed as per the new Turkish Seismic Code for Buildings-2018, and 3D FE model of the building is established. Based on the established FE model, a total number of six buildings are considered depending on certain percentage increase in beam, slab, and column. The time-history response analyses (THA) are performed separately for only horizontal (H) and horizontal +vertical (H+V) earthquake motions to make a comparison between the load cases. The analysis results are presented comparatively in terms of the monitoring parameters of the base overturning moment (M_o), the top-story lateral displacement (d_L) and the top-story vertical displacement (d_V). The obtained results reveal that the base overturning moment and the top-story vertical displacement are affected by vertical earthquake motion regardless of the increase in the dimension of beam, slab, and column. However, vertical earthquake motion is not effective on the top-story lateral displacement due to no change between H and H+V load. The dimensional increase in either slab or beam leads to a considerable increase in the base overturning moment and the top-story vertical displacement while causing decrease in the top-story lateral displacement. In addition, the dimensional increase in column has a positive effect on the decrease in the monitoring parameters of the base overturning moment (M_o), the top-story lateral displacement (d_L) and the top-story vertical displacement (d_V).

• Journal of Korean Tunnelling and Underground Space Association
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• v.22 no.4
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• pp.337-346
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• 2020

Traffic jam and congestion in urban areas has caused the need to improve the utility of underground space. In response, research on underground structures is increasingly being conducted. Notably, a double-deck tunnel is one of the most widely used of all those underground structures. This double-deck tunnel is separated by the middle slab into the upper and lower roadways. Both vehicle load and earthquake load cause the middle slab to exhibit dynamic behavior. Earthquake-related response characteristics, in particular, are highly complex and difficult to interpret in a theoretical context, and thus experimental research is required. The aim of the present study is to assess the stability of a double-deck tunnel's middle slab of the Collapse Prevention Level and Seismic Category 1 with regard to the presence of vibration-damping Rubber Bearings. In vibration table tests, the ratio of similitude was set to 1/4. Linings and vibrating platforms were fixed during scaled model tests to represent the integrated behavior of the ground and the applied models. In doing so, it was possible to minimize relative behavior. The standard TBM cross-section for the virtual double-deck tunnel was selected as a test subject. The level of ground motion exerted on the bedrock was set to 0.154 g (artificial seismic wave, Collapse Prevention Level and Seismic Category 1). A seismic wave with the maximum acceleration of 0.154 g was applied to the vibration table input (bedrock) to analyze resultant amplification in the models. As a result, the seismic stability of the middle slab was evaluated and analyzed with respect to the presence of vibration-damping rubber bearings. It was confirmed that the presence of vibration-damping rubber bearings improved its earthquake acceleration damping performance by up to 40%.

• ICROS
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• v.15 no.1
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• pp.37-43
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• 2009

철강제조공정에서 강판을 만드는 공정이 압연이다. 압연공정은 연속주조 공장에서 생산되는 Steel Slab, Bloom, Billet등의 반제품을 높은 온도로 재 가열하고 물리적인 힘을 가해 압연하는 열간압연(이하 열연)과 열연으로 얇아진 강판을 열을 가하지 않고 냉각상태에서 압연하는 냉간압연으로 나뉜다. 본 원고에서는 열연 공정의 가열로 온도제어에 적용한 MFA(Model Free Adaptive Controller)를 소개하고자 한다.

• 한국도로학회:학술대회논문집
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• 2010.09a
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• pp.179-184
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• 2010

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.905-906
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• 2012

• Magazine of the Korea Concrete Institute
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• v.20 no.2
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• pp.19-24
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• 2008

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.9
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• pp.1020-1027
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• 2008

In this paper, the refraction angles and the critical angles of metamaterials which is assumed by the Drude model are analytically studied. To analyze the electromagnetic reflection and the transmission properties of metamaterial slab, we used "-1" for the permeability and the permittivity at 30 GHz in Drude model for metamaterials in this paper, respectively. Due to the variation of signes of material constants for frequency ranges in Drude model, the derived refraction angle and the critical angles for each frequency ranges are differently observed. The results in this paper show that the properties the refraction angles and the critical angles for the broadband in metamaterials can be used to understand the electromagnetic properties of metamaterials and microwave applications.

• Journal of the Korean Geotechnical Society
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• v.23 no.10
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• pp.109-119
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• 2007

As the number of CFRD constructions increases, the necessity of an accurate assessment on its behavior also has been increasing. The performance of concrete faced rockfill dam (CFRD) under different water levels is a great concern of dam engineers and designers in the world. However, domestic research on CFRD design and construction has not been performed sufficiently. This study deals with three centrifuge model tests, mainly investigates quantitatively the deformation of the concrete faced slabs and settlements on the crest with different face slab stiffness. The prototype of a centrifugal model dam is half size of domestic CFRD dam. Detailed material preparation, model design, model set-up, model instrumentation and testing procedures are presented. In order to simulate the prototype concrete faced slab, three kinds of thin fiberglass plates with different thickness were adopted in three model tests. Finally, the centrifuge test results were compared with field measurements of domestic dams, which showed that the centrifuge tests were performed successfully.