• Journal of the Korean Society for Heat Treatment
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• v.19 no.4
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• pp.200-207
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• 2006

In addition to the basic properties of the base and top coating agents, corrosion resistance of non-chrome magni 565 coating and characteristics of coating film when coated to steel substrate were studied. The system had a good wettability at room temperature. Moreover, both the contact angle and surface tension were affected little by the viscosity of coating agent and surface roughness of the steel substrate. And the samples coated with optimal conditions showed a great corrosion resistance in salt spray test with 1500 hours or longer of initial appearance time of rust. The coating film was composed of overlapping layer of zinc and aluminium flakes, and the thickness of base coat increased with an increase of base coat viscosity. Based on the C-F peaks of 1,1-Difluoroethaen homo-polymer, it was thought that the base coat was an inorganic polymer bond layer. Meanwhile, the top coat showed C-F peaks of polytetrafluoroethylene with C-H peaks of phenol in FT-IR analysis. From the lower weight loss of base coat in TG analysis, it was thought that cross linking density of base coat was larger than that of top coat. It was thought that the small exothermic reactions observed in DSC curves were due to the thermosetting resins contained in the coating agents. Compared to the non-coated specimen, the coated sample showed more higher polarization resistance and corrosion potential with lower corrosion current density.

• Journal of Animal Science and Technology
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• v.52 no.3
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• pp.237-244
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• 2010

In order to investigate the physiological properties of velvet antler of elk (Cervus e. canadensis) raised in Korea, antlers (n=378) were collected from deer in 8 provinces including Gyeonggi-do (n=53), Gangwon-do (n=49), Chungcheongbuk-do (n=62), Chungcheongnam-do (n=68), Jeollabuk-do (n=52), Jeollanam-do (n=15), Gyeongsangbuk-do (n=30) and Gyeongsangnam-do (n=49). The exterior characteristics (weight, length, girth and crown) of all antlers were measured, and 18 antler samples were randomly selected for measurement of interior characteristics such as specific gravity, capacity and diameter of cross section. The mean antler weight, length of the main beam and mean length of upper section were $4.87{\pm}1.79\;kg$, $83.7{\pm}13.2\;cm$ and $40.6{\pm}11.4\;cm$, respectively. Mean girth of the top, middle and base of the main beam were $27.1{\pm}5.9\;cm$, $22.1{\pm}3.6\;cm$ and $22.9{\pm}3.6\;cm$ respectively, indicating a slight narrowing in the middle of the antler. In each of the tines, the girth at the base was markedly thicker compared to the top. The depth of the crown at the top of the antler, and the average number of crowns and tines were $14.1{\pm}7.0\;cm$, $2.1{\pm}0.6$ and $3.0{\pm}0.5$, respectively. Although there was no significant difference in mean specific gravity between top and base, mean specific gravity of main beam tended to increase from top to base of the antler with decreasing capacity. Additionally, the inner diameter of the base of the antler was significantly reduced compared to that of the top, indicating a greater integumental thickening due to mineralization. Information on the morphological and physiological properties of elk antlers is scarce. Therefore, these results may be useful in providing basic information for the physiological properties of antler, and encourage further studies on antler morphology in other deer species showing species specific differences.

• Wind and Structures
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• v.30 no.4
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• pp.423-432
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• 2020

A steel high-rise building (HRB) with 15 stories was analyzed under the dynamic load of wind or four different earthquakes taking into consideration the effect of soil-structure interaction (SSI) and using tuned mass damper (TMD) devices to resist these types of dynamic loads. The behavior of the steel HRB as a lightweight structure subjected to dynamic loads is critical especially for wind load with effect maximum at the top of the building and reduced until the base of the building, while on the contrary for seismic load with effect maximum at the base and reduced until the top of the building. The TMDs as a successful passive resistance method against the effect of wind or earthquakes is used to mitigate their effects on the steel high-rise building. Lateral displacements, top accelerations and straining actions were computed to judge the effectiveness of the TMDs on the response of the steel HRB subjected to wind or earthquakes.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.401-414
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• 2010

Top Base Foundation(TBF) is a stabilization method for light weight structures particularly in the soft ground. It is widely used for the increment of bearing capacity and restraining settlement of foundations when the bearing capacity of ground is not enough. However, when the design values from exiting Japanese standard are compared with the observation values from the field measurement, the bearing capacity of exiting standard estimated smaller For this reason, it is necessary to establish more reasonable prediction technique considering to understand the behavior of TBF in soft ground. In this study, 1/5 scale model tests were performed in the laboratory. Also, full scale tests were carried out in order to investigate the behavior of TBF with various shapes. In addition, about 100 sites measurement data were evaluated to investigate the behavior of TBF in various ground conditions. Based on the results of the model tests and field measurement data, it was possible to establish more reasonable the bearing capacity equation of TBF considering various N-value of soil, the effect of underground water and failure shapes.

• Journal of the Korean Geotechnical Society
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• v.26 no.7
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• pp.135-145
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• 2010

Top Base Foundation (TBF) is widely used for the increment of bearing capacity and restraining settlement of foundations when the bearing capacity of ground is not enough. The design of bearing capacity obtained from exiting Japanese standard underestimates considerably what is compared with the observation values from the field measurement. Therefore, intensive model tests and site observation programs are carried out to establish more reasonable prediction technique and understanding of TBF in soft ground. In this study, 1/5 scale model tests are performed in order to investigate the behavior of TBF with various shapes in a laboratory. Also, about 100 sites measurement data are evaluated to investigate the field behavior of TBF in various ground conditions. Based on the results of the model tests and field measurement data, it was possible to introduce more reasonable bearing capacity equations of TBF considering N-value of soils, the effect of underground water and failure mechanisms.

• Earthquakes and Structures
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• v.2 no.4
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• pp.397-412
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• 2011

In this paper, the seismic response of elevated broad and slender liquid storage tanks isolated by elastomeric or sliding bearings was investigated. The accuracy of predictions of SAP2000 vs. 3D-BASIS-ME programs was examined. A comparative study of the performance of base isolated tanks when isolation bearings are placed at the top or at the bottom of the supporting tower structure was conducted. It was found that base isolation is quite effective in reducing the earthquake response of elevated liquid storage tanks in which high reductions of base shear and shaft displacement were achieved. Modeling the isolated tanks in SAP2000 was very successful in producing results that are nearly identical to those of program 3D-BASIS-ME. Placing the isolators at the top of the shaft in elevated tanks proved to be much better than placing them at the bottom.

• Structural Engineering and Mechanics
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• v.51 no.2
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• pp.277-297
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• 2014

Since the isolation bearings undergo large displacements in base-isolated structures, impact with adjacent structures is inevitable. Therefore, in this investigation, the effect of impact on seismic response of isolated structures mounted on double concave friction pendulum (DCFP) bearings subjected to near field ground motions is considered. A non-linear viscoelastic model of collision is used to simulate structural pounding more accurately. 2-, 4- and 8-story base-isolated buildings adjacent to fixed-base structures are modeled and the coupled differential equations of motion related to these isolated systems are solved in the MATLAB environment using the SIMULINK toolbox. The variation of seismic responses such as base shear, displacement in the isolation system and superstructure (top floor) is computed to study the impact condition. Also, the effects of variation of system parameters: isolation period, superstructure period, size of seismic gap between two structures, radius of curvature of the sliding surface and friction coefficient of isolator are contemplated in this study. It is concluded that the normalized base shear, bearing and top floor displacement increase due to impact with adjacent structure. When the distance between two structures decreases, the base shear and displacement increase comparing to no impact condition. Besides, the increase in friction coefficient difference also causes the normalized base shear and displacement in isolation system and superstructure increase in comparison with bi-linear hysteretic behavior of base isolation system. Totally, the comparison of results indicates that the changes in values of friction coefficient have more significant effects on 2-story building than 4- and 8-story buildings.

• Proceedings of the Korean Geotechical Society Conference
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• 1991.10a
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• pp.312-331
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• 1991

Top-down Method of basement construction technique has been applied for building of the deep basement car park the close proximity of priceless historic buildings in LONDON. Numerical analysis for the prediction of ground movement of the surrounding buildings was performed in order to compare the field data at the various stages of excavation and support. The predicted results from the elasto-plastic analytical method were compared with the observed data and the agreement is very satisfactory. It may be concluded that the system of diaphragm wall supported by the permanent base slabs (Top-Down Method) was proved to be the most effective technique in terms of reducing any critical damage to the surrounding buildings.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.197-199
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• 2011

To utilize the Top-Down construction method, it is required to analyse building area, floors, and soil conditions to choose the three basic elements of retaining wall, base column, and floor structure. The purpose of this research is to compare the methods of Top-Down with other construction methods. The research method is to analyse the project conditions of Top-Down project cases. The aim is to develop a method of selecting alternatives, considering construction characteristics, work schedule, supporting methods, foundation types.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.5
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• pp.130-135
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• 2010

Paint is used as top coat in Automobile Refinishing that is divided into 1K paint of base type and 2K paint of urethane type. after using 1K paint, it can be reusable. However 2K paint is not available that is mixed a certain amount of base with hardner, so 2K paint has to be used all at a time or discarded the rest. This study covered that colored Urethane paint and colorless urethane paint in top coating process of AR. Top coat urethane paint is divided into colored urethane paint and transparent urethane paint like clear coat. Colored urethane paint is used for paint that contains resin, pigment, solvent and additives. It is color such as black and white. While transparent urethane paint is used for paint that contains resin, solvent and additives. Urethane paint has a paint system that cur after several hours of mixing base and hardner. By a paint technician of a field and empirical data, we can also recognize that according to worker's paint style and experience, although he or she paint same car model and area, paint use of one's is different. There aren't guidelines workers refer to about paint use by car models and work scope because ARP works various car models that are in different color, size and area. After using urethane paint, the rest of paint has come, and there are highs and lows in paint use each time he or she works. Therefore, this study suggest a basic guideline to use paint efficiently and regularly by understanding area, the type of work, and paint use that are appropriate for each car model and regardless of workers and work scopes in AR.