• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.5 s.142
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• pp.737-744
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• 2005

This study was aimed to provide the measurement data and shape classification of the head of the Korean male children for the headwear sizing systems. Five hundred twenty male children, aged nine to twelve years, participated f3r this study. The 17 regions on the head and height, weight of the subjects were directly measured by the expert experimenters. Factor analysis, cluster analysis, GLM analysis and Tukey HSD test were performed using these data. Through factor analysis, low factors were extracted upon factor scores and those factors comprised $69.76\%$ for the total variances. Three clusters as their head shape were categorized using four factor scores by cluster analysis. Type 1 was characterized by the widest width and Bitragion arc, shortest head length. Type 2 had the longest head length and the widest side width and the highest head length and head circumference. Type 3 was characterized by the smallest head circumstance, head width and side width, and medium head length.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.10a
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• pp.271-274
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• 2009

This paper deals with an evaluation of the product quality according to intermesh of the roller straightening process of a steel cord. To perform the experiments, a single-layered steel cord with three wires is selected as a target. Intermeshes at inlet and outlet of the roller straightening device are selected as a respective design parameter. According to two intermeshes of the roller straightening device, a design table is generated and experiments were performed. Three assessment items of the product quality, such as the residual torsion, the arc-height and the pre-forming ratio, are measured in each experimental case for the quantitative evaluation of a steel cord. Based on the measured data, the sensitivity of two intermeshes was analyzed and the prediction equation for the product quality of a steel cord was also constructed from the regression analysis.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1995.04a
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• pp.203-210
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• 1995

A construction method for continuous prestressed Composite Bridges(PCB's) is developed and successfully applied to the design of two-span continuous PCB's of five different span lengths. The construction of continuous PCB's goes through 17 different loading conditions. for each loading condition, the allowable stress design method is used to determine section properties. The analytical results of two-span continuous PCB's arc compared with those of simple PCB's. The comparison shows that the use of the proposed method can reduce 10-15 percents of the concrete section area and approximate 28 percents of the steel section area, as well as 5-8 percents of the girder height. The study indicates that the use of the proposed PCB's method can significantly reduce construction and maintenance costs of bridges.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.3
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• pp.135-142
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• 2004

In this paper, the magnetic circuit characteristics and the current/torque analysis of a Spoke Type permanent magnet motor have been researched, compared with the SPM Type motor. In the magnetic circuit analysis, the characteristic of air-gap flux density has been analyzed according to the variation of the number of pole and the ratio of magnet height to arc length using finite element method and circuit equations. Moreover, the electromagnetic and the reluctance torque have been analyzed by the current profile, which is obtained from the variation of turn-on angle, and these informative data has been utilized for the overall characteristics of the Spoke Type BLDC motor.

• Transactions of Materials Processing
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• v.21 no.3
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• pp.172-178
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• 2012

We performed a shot peening test and used a 2-D finite element model which predicts the compressive residual stress distribution below the material's surface. In this study, the concept of 'impact cycle' is introduced to account for the irregularity in the shot's impact position during testing. The impact cycle was imbedded in the finite element model. In the shot peening test, shot bombarded a type-A Almen strip surface with different impact velocities. To verify the proposed finite element model, we compared the deformed cross sectional shape of the Almen strips with the shapes computed by the proposed finite element model. Good agreement was noted between measurements and the finite element model predictions. With the verified finite element model, a series of finite element simulations was conducted to compute the residual stress distribution below the material's surface and the characteristics of these distributions are discussed.

• Journal of the Korean Society of Industry Convergence
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• v.3 no.1
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• pp.69-75
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• 2000

Multichip packages are comprised of dissimilar materials which expand at different rates on heating. The differential expansion must be accommodated by the various structural elements of the package. A types of heat exposures occur operation cycles. This study presents a finite element analysis simulation of flip-chip among multichip. The effects of geometries and material properties on the reliability were estimated during the analysis of temperature and thermal stress of flip-chip. From the results, it could be obtained that the more significant parameters to the reliability of flip-chip arc chip power cycle, heat convection and height of solder bump.

• Journal of the Korean Solar Energy Society
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• v.21 no.2
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• pp.35-43
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• 2001

The results of numerical simulation on the performance of a solar chimney system in building are described. The inside surface temperature of four walls within the solar chimney arc calculated with solar radiation and outdoor temperature in summer. The air within the solar chimney is heated by conduction, convection and radiation. Air temperature distribution from the bottom to the top and outlet air temperature can be obtained by solving energy balance equation. Since the buoyance or stack effect is affected by temperature difference between the bottom and the top within the solar chimney. It is evaluated using inlet and outlet temperatures. It is expected that natural ventilation by the solar chimney of witch the height is 7.8m and the cross sectional area is $4.93m^2$ can provide about $6400m^3/h$ on sunny day.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.940-945
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• 2010

There are human casualties that caused by slope-stability related disasters such as landslide and debris flow during typhoon and rainy season every year in Korea. These disaster sites can be analyzed systematically using digital topographic data and aerial photogrammetry. In this study, geographical factors such as slope degree, geology, height, and soil depth are analyzed in four landslide-disaster sites from Muju, Jinan, and Jangsu County based on digital elevation maps generated by ArcGIS. Each site showed different characteristics in geology and geography and it is found that GIS can be utilized for the visualization of steep-slope failure areas.

• Proceedings of the KWS Conference
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• 2003.11a
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• pp.169-171
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• 2003

In this paper, the prediction for the optimized bead geometry such as bead width, height, penetration and bead area in the Gas Metal Arc (GMA) welding with Taguchi method is presented. An orthogonal array, and the Signal-to-Noise (S/N) ratio employed to investigate the welding quality characteristics together in the selection of process parameters in the GMA welding process, to analyze the effect of each process parameter on the bead geometry and to finally determine the process parameters with the optimal bead geometry. Experimental results fi-om this research show that the Taguchi method provides an effective tool to enhance the accuracy of the optimized bead geometry.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.2
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• pp.15-22
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• 1998

The effects of shot peening an the fatigue strength are studied in this paper. Applying the multistage shot peening on the material. the relation between the residual stress and fatigue strength compressive is investigated. Observing tensile strength elongation. reduction of area. hardness. and roughness. the results can be summarized as follows ; 1.The change of mechanical properties is small before and after the shot peening is carried out. The change of hardness is also small in high hardness material. 2.The surface roughness does not affect the fatigue strength. but the surface roughness is improved by multi-stage shot peening. 3.The fatigue strength of multi-stage shot peening material is 756MPa and is 1.78 times higher than that of un-peened material. 4.The maximum compressive residual strength of multi-stage shot peening material is -792MPa the fatigue strength seems to be improved by residual stress.