• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.10
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• pp.155-162
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• 2019

Hybrid precast concrete panel is a wall element that is able to quickly construct the core wall structure for moderate-rise modular buildings. Hybrid precast concrete panel has unique characteristics which is a pair of C-shaped steel beams combined at the top and bottom of a concrete wall, In this study, an improved anchorage detail for vertical rebar is proposed to ensure the lateral force resistance performance of hybrid precast concrete panel emulating monolithic concrete wall. Also, the structural performance of horizontal connection is investigated experimentally with the bolt spacing parameter. And the behavior of hybrid precast concrete panel with the improved detail is compared with the monolithic concrete wall tested in a previous study. Finally, the required thickness of C-shaped steel beam to eliminate or minimize the deformation in horizontal connection is calculated by prying action equation.

• Computers and Concrete
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• v.32 no.5
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• pp.527-541
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• 2023

This paper emphasizes the use of CFT columns in frame structures subjected to strong horizontal forces and shows that the efficiency of using CFT columns is increased when the plastic design approach is adopted. Because the plastic design approach is based on redistribution of the force of the internal member, a double node for the rotational degrees of freedom, where the adjacent two rotational degrees of freedom can be connected by a non-dimensional spring element, is designed and implemented into the formulation. In addition, an accompanying criterion is considered in order to make it possible to describe the continuous moment redistribution in members connected to a nodal point up to a complete plastic state. The efficiency of CFT columns is reviewed in comparison with RC columns in terms of the cost and the resistance capacity, as defined by a P-M interaction diagram. Three representative frame structures are considered and the obtained results show that the most efficient and economical design can be expected when the use of CFT columns is considered on the basis of the plastic design, especially when a frame structure is subjected to significant horizontal forces, as in a high-rise building.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.1073-1087
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• 1993

Many investigations have been carried out concerning tillage tool performance, including energy requirement . Since the performance of tillage could also be evaluated through the change of soil , then it is necessary to investigate the soil cutting process and the pattern of soil failure. This study was conducted using indoor soil bin, STILT (Soil Tillage Tool Interaction) system. The result shows that the soil bin experiments could provide the clear understandings about phenomena of soil failure. The movement of sil , the successive failures was clearly visualized. The relations between the horizontal and vertical forces to the linear motion blade, the shear force on the shear plane which devides soil layer into several segments were indicated by the fluctuation/vibration of the recorded resistance and forces. The results show that the horizontal force(Fx) and vertical force (Fz) develope their frequencies as the change of velocity of blade (10, 20, 40 mm/sec) for each cutting angle (35, 45, 60 degrees). Resultant force of Fx and Fz are much influenced by the cutting angle.

• Structural Engineering and Mechanics
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• v.46 no.6
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• pp.775-790
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• 2013

Deformation analysis is a major concern in many geotechnical applications. In this paper, the deformation behavior of a geocell mattress subjected to symmetric loads was studied. The mattress was idealized as an elastic foundation beam. The horizontal beam-soil interfacial shear resistances at the beam top and bottom sides were taken into account by assuming the resistances to be linear with the relative horizontal displacements. A decoupled iterative method was employed to solve the differential displacement equations derived from the force analysis of a beam element and to obtain the solutions for the deformations and internal forces of the geocell reinforcement. The validity of the present solutions was verified by the existing finite element method and power-series solutions.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05a
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• pp.565-570
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• 1998

An interfacial condensation heat transfer phenomenon in a steam/water countercurrent stratified flow in a nearly horizontal pipe has been experimentally investigated. The present study has been focused on the measurement of the temperature and velocity distributions within the water layer. In particular, the water layer thickness used in the present work is large enough so that the turbulent mixing is limited and the thermal stratification is established. As a result, the thermal resistance of the water layer to the condensation heat transfer is increased significantly. An empirical correlation of the interfacial condensation heat transfer has been developed. The present correlation agrees with the data within $\pm$15%

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.471-476
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• 2000

Long-term behavior of reinforced clayey soil by model tests were performed to investigate the effect of reinforcement during loads and under static loads. In order to determine proper contents by weight of monofilament polypropylene fiber and calcium carbonate, the drying shrinkage and compressive strength tests had been conducted before model tests. Model tests were run on a clayey soil mixed with or without reinforcement and test specimen in test apparatus was placed in air dry for 7days before load application. In the case of fiber reinforced soil, the horizontal strain was lower than others during loads because the presence of fibers increased the soil's resistance to deformation. All of reinforced clayey soil, horizontal strain decreased as the water content decrease under static loads.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.12
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• pp.1049-1056
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• 2000

In this study, condensation heat transfer coefficients(HTCs) of 2 nonazeotropic refrigerant mixtures of HFC32/HFC134a and HFC134a/HCFC123 at various compositions were measured on a horizontal smooth tube. All data were taken at the vapor temperature of 39$^{\circ}C$ with a wall subcooling of 3~8K. Test results showed that HTCs of tested mixtures were 11.0~85.0% lower than the ideal values calculated by the mass fraction weighting of the pure components HTCs. Thermal resistance due to the diffusion vapor film was partly responsible for the significant reduction of HTCs with these nonazeotropic mixtures. The measured data were compared against the predicted ones by Colburn and Drew\`s film model and a good agreement was observed.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.85-88
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• 2008

The purpose of this study was to investigate the seismic behavior of precast concrete segmental bridge piers with shear resistance connecting structure. A model of precast concrete segmental bridge columns with shear resistance connecting structure was tested under a constant axial load and a cyclically reversed horizontal load. A computer program, RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), for the analysis of reinforced concrete structures was used. The proposed numerical method for the seismic behavior of precast concrete segmental bridge piers with shear resistance connecting structure is verified by comparison with reliable experimental results.

• Fire Science and Engineering
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• v.24 no.6
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• pp.82-88
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• 2010

Major structural elements such as columns and beams are designed to withstand the vertical and horizontal loads. Futhermore, when the structural elements were engulfed with fire the structural stability should be stand without failure. The beams have been developed in aspects of structural stability but an evaluation of fire performance was not done. So the data of fire resistance performance of beams filled with concrete at web on H-section is not known. The purpose of this paper is to analyse the correlation between temperature analysis and fire test with the beams and to show the fire resistance performance with two methods.

• Journal of Biosystems Engineering
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• v.25 no.3
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• pp.179-186
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• 2000

Interactions between wheel lug surfaces and soil were analyzed through wheel motion. In this paper, lug surfaces such as trailing and leading lug sides and a lug face were analyzed and reported. The interactions between the surfaces and soil were expressed as the horizontal and vertical directions of resultant forces acting on the surfaces. There analysis indicated qualitatively that (1) the trailing lug side is mainly related to produce motion resistance and reaction to dynamic load, (2) the lug face is related to produce not only the motion resistance, the reaction to the dynamic load but also the traction and (3) the leading lug side is mainly related to produce the traction and the reaction to the dynamic load. Experiments were conducted to prove the results of the motion analysis. Normal and tangential forces acting on the surfaces were measured, and the traction, the motion resistance and the reaction to the dynamic load were calculated with wheel rotational and lug design angles. The experiments proved that the results of wheel motion analyses above mentioned as (1), (2) and obtained from the analysis were correct.