• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.1149-1152
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• 2007

Many kind of damping materials are generally used on concrete slab in apartment building to reduce floor impact noise level. Lately, multi-layered damping material that is consist of several materials are used to improve the effect of floor impact noise insulation. In this study, dynamic stiffness of multi-layered damping material that is consist of common materials such as expanded polystyrene(EPS), expended polyethylene(EPE), ethylene vinyl acetate(EVA) and polyester was investigated. It was found that dynamic stiffness of multi-layered damping material could be estimated if know value of each layer that compose whole structure. And it was found that dynamic stiffness of whole structure did not change even if change order that build layer.

• Journal of the Korean housing association
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• v.13 no.6
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• pp.111-120
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• 2002

The purpose of this study is to understand the trends of urban housing in the age of modernization in Western cities since 1970's, and to provide the useful data for diversifying urban housing types in Korea. Although the housing types can be categorized in many ways according to the points of view, this study classifies 11 types by a criterion of urban composition elements. Among 11 urban housing types, one type, free-standing slab structure, has been mainly applied to Korean situation. The reason might be that the free-standing structure type is the most efficient one in terms of land use and block organization, but it results in a monotonic condition of urban housing blocks. Therefore, taking local characteristics and urban contexts in Korea into consideration, the future urban housing design should be developed in different ways of making local life styles possible in them, by adopting various types of Western urban housing precedents.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.982-987
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• 2002

Recently, as size of building structure becomes larger, mat area of building structure is supported on Inhomogeneous foundation. The equipment machineries in building are mostly on basement story. The slab of the lowest basement story with equipment machineries is considered as plate supported on foundation with concentrated masses. In this paper, vibration analysis of rectangular thin plate is done by use of rectangular finite element with 4 nodes. The solution of this paper are compared with existing solution and natural frequencies of thin plates, with concented mass, on inhomogeneous Pasternak foundation are calculated

• Steel and Composite Structures
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• v.11 no.2
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• pp.169-181
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• 2011

The behavior of connections between open sandwich slabs and double steel skin composite walls in steel plate-concrete(SC) structure is investigated by a series of experimental programs to identify the roles of components in the transfer of forces. Such connections are supposed to transfer shear by the action of friction on the interface between the steel surface and the concrete surface, as well as the shear resistance of the bottom steel plate attached to the wall. Experimental observation showed that shear transfer in slabs subjected to shear in short spans is explained by direct force transfer via diagonal struts and indirect force transfer via truss actions. Shear resistance at the interface is enhanced by the shear capacity of the shear plate as well as friction caused by the compressive force along the wall plate. Shear friction resistance along the wall plate was deduced from experimental observation. Finally, the appropriate design strength of the connection is proposed for a practical design purpose.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04a
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• pp.211-216
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• 1998

Parameter analysis of mass concrete structures of two types subjected to heat of hydration and surface heat transfer is presented. Thermal stress analysis is conducted through the 3D FEM program. Thermal and mechanical properties of concrete, for example, conductivity, heat capacity, density, thermal expansion coefficient are varied from 80% to 120% of a reference value, and the change of thermal stress against the parameter is achieved respectively. As a result of the analysis, the parameter affecting thermal stress most significantly is an adiabatic temperature rise in the case of wall-type structure, and an initial temperature of concrete in the case of slab-type structure, respectively.

• Journal of The Korean Astronomical Society
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• v.49 no.1
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• pp.19-23
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• 2016

Magnetic decreases are often observed in various regions of interplanetary space. Many studies are devoted to reveal the physical nature and generation mechanism of the magnetic decreases, but still we do not fully understand magnetic decreases. In this study, we investigate the structure of a magnetic decrease observed in a corotating interaction region using multi-spacecraft measurements. We use three spacecraft, ACE, Cluster, and Wind, which were widely separated in the x- and y-directions in the geocentric solar ecliptic (GSE) coordinates. The boundaries of the magnetic decrease are the same at the three locations and can be identified as tangential discontinuities. A notable feature is that the magnetic decrease has very large dimension, ≳ R_E, along the boundary, which is much larger than the size, ~ 6 R_E, along the normal direction. This suggests that the magnetic decrease has a shape of a long, thin rod or a wide slab.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.10
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• pp.1206-1211
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• 2014

This study has been conducted to confirm the effect of sacrificial anode cathodic protection system for 90 days to protect corrosion on pier that is located in Korea. The cathodically protected structure was a slab and a pile cap. Before the construction of cathodic protection system, the macrography was carried out. As a result of the macrography, many corrosion traces were confirmed in this structure. The trace was mainly focused on joint and zones that concrete cover was eliminated. To apply the cathodic protection system, many onsite techniques have been adopted. In addition, to confirm the inner state of steel in concrete properly, a corrosion monitoring sensor (DMS-100, Conclinic Co. Ltd) has been applied. Test factors were corrosion & cathodic protection potential, 4 hour depolarization potential, resistivity and current density. After 90 days from the installation of cathodic protection system, it could confirm that proper corrosion protection effect was obtained by considering the result of tests.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2003.05a
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• pp.147-152
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• 2003

Passage of time axial shortening in the cores and columns of tall concrete buildings requires special attention to ensure proper behavior for strength of the structure and the nonstructural element. The effects of column shortening, both elastic and inelastic, take on added significance and need special consideration in design and construction with increased height of structures. In this paper, the compensation method of column shortening for reinforced concrete structure are introduced. It could be concluded that the survey is a significant factor for the compensation instance of column shortening.

• Journal of Korean Association for Spatial Structures
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• v.12 no.4
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• pp.57-69
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• 2012

This study investigated the behaviors of the gabled hyperbolic paraboloid shell structure subjected to differential settlement and the horizontal displacement due to the elongation of tie rod/beam on supports. Two types of shell structure with different roof slopes are used in study; conventional type which has perimeter beams around the shell panel, and simple type which removes the edge beams along the slab edge line. The effect of the removal of edge beam under vertical or horizontal displacement on supports, and the roof slope was compared using the finite element analysis.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1707-1711
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• 2008

Landing pier is connect from onshore to offshore with bridge type that a coast structure. The sub-structure is consisted of vertical or batter pile and combined reinforced concrete slab. These days useful design method of quay wall of landing pier type for pile foundation analysis abide by approximate depth of pile supported method, "Harbor and port design criterion, 2005 The ministry of land transport and maritime affairs". The approximate depth of pile supported is calculated two kind of method that one is assume to below depth of 1/$\beta$ from assumed submarine surface and other is 1st fixpoint depth by Chang(1937)'s theory. By this paper, FEM dynamic analysis of 3-dimensions was achieved that it has compared pile fixed end modeling with elastic spring modeling base on winkler theory.