• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.673-680
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• 2017

sump pump is a system that draws in water that is stored in a dam or reservoir. They are used to pump large amounts of water for cooling systems in large power plants, such as thermal and nuclear plants. However, if the flow and sump pump ratio are small, the flow rate increases around the inlet port. This causes a turbulent vortex or swirl flows. The turbulent flow reduces the performance and can cause failure. Various methods have been devised to solve the problem, but a correct solution has not been found for low water level. The most efficient solution is to install an anti-vortex device (AVD) or increase the length of the sump inlet, which makes the flow uniform. This paper presents a computational fluid dynamics (CFD) analysis of the flow characteristics in a sump pump for different sump inlet lengths and AVD types. Modeling was performed in three stages based on the pump intake, sump, and pump. For accurate analysis, the grid was made denser in the intake part, and the grid for the sump pump and AVD were also dense. 1.2-1.5 million grid elements were generated using ANSYS ICEM-CFD 14.5 with a mixture of tetra and prism elements. The analysis was done using the SST turbulence model of ANSYS CFX14.5, a commercial CFD program. The conditions were as follows: H.W.L 6.0 m, L.W.L 3.5, Qmax 4.000 kg/s, Qavg 3.500 kg/s Qmin 2.500 kg/s. The results of analysis by the vertex angle and velocity distribution are as follows. A sump pump with an Ext E-type AVD was accepted at a high water level. However, further studies are needed for a low water level using the Ext E-type AVD as a base.

• The Journal of the Acoustical Society of Korea
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• v.32 no.5
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• pp.423-429
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• 2013

The present study aimed to find the most sensitive placement of the skull to perceive speech through the bone vibrator in various protection methods while being exposed to noise. Twenty young normal-hearing adults (10 male and 10 female) participated in the study. As stimulus, Korean spondee words were presented via one of five skull locations (i.e., jaw angle, condyle, temple, mastoid, and vertex), while the participants wore one of four protection methods (i.e., ear form, ear plug, ear muff, and ear form and muff together) against white noise in one of four noise directions (i.e., 0, 90, 180, 270 degrees). The results showed: 1) there was a significant difference among the five skull locations with condyle being the most sensitive placement; 2) there was a significant difference among the four protection methods, with the ear form plus ear muff condition (or dual protection) providing the lowest threshold; 3) when exposed to noise from 90 degrees, the significantly lowest threshold was found; 4) there was no significant difference in results by gender. The pattern of results suggests that the communicative condition via the condyle bone conduction and the dual protection of the air conduction under any noise direction might be ideal for preventing noise-induced hearing loss, although further studies should be undertaken in this area.

• Journal of the Korean Society of Costume
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• v.64 no.3
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• pp.77-92
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• 2014

The purpose of this research is to examine the expression methods of Haute Couture designers' high value-added jacket designs, In order to achieve this, the positions and sizes of the design component items of tailored jackets designed by Haute Couture designers from the 1940s to the 1970s were analyzed. The results of the analysis are as follows. First, the silhouette changed while leading the contemporaneous fashions, and such changes could be confirmed by the width and length of the jacket's shoulder, chest, waist, and hem that determine the silhouette. Particularly, the length of the chest changed which signifies that the depth of the armhole was playing an important role in the production of high value-added jackets in relation to the sleeves and the fit of jackets. Second, the position and the size of the dart are the components that can express the fit of a jacket and the designer's creativity, The starting point position of the dart and the position passing by waist, and the position of the end of the dart were placed in the position beyond B.P. depending on the designer's creativity and techniques, deriving the changes of the silhouette and creating high value-added jackets. Third, the tailored collar, which was a three-dimensional component made up of the upper collar, gorge line, lapel, and break line, was an important component that could express high value-added jackets. Changes in the width and the height of the break line position of the sides of the neck were represented as changes in the neck size of the collar, and changes in the vertex locations of the upper collar corner-point, the gorge line (the corner-point of the lapel and V zone) were also represented as diverse tailored collar designs. And the differences in the width and the length of each component of the collar were related to each other and represented as changes in the slope and angle of the collar outline. Fourth, the changes in sleeve designs of the jacket were in such items as the width of the sleeve opening, the width of the sleeve hem, and the length of the sleeve, and were represented as diverse sleeve designs such as widened sleeve opening types, and straight line types.

• The korean journal of orthodontics
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• v.30 no.1 s.78
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• pp.53-66
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• 2000

This study was performed to find out the effect of projection errors on cephalometric linear and angular measurements according to head rotation during taking lateral cephalometric radiographs. Seventeen skulls with permanent dentition and no gross asymmetry were obtained from the Department of Anatomy, Medical School, Chosun University. Total 527 x-ray films were taken with $1^{\circ}$ interval from the reference position($0^{\circ}$) to ${\pm}15^{\circ}$ around the vertical axis (Z axis) which is perpendicular to the midpoint of the line connecting the center of two ear rods in submento-vertex direction. Statistical analysis was performed by paired t-test if there were statistically significant differences between the mean of the reference position($0^{\circ}$) and that of each rotation angle. The following results were obtained. 1. The projection errors of angular measurements were smaller than those of linear measurements. 2. The projection errors of angular measurements including midline landmarks were smaller than those including bilateral landmarks. 3. The horizontal linear measurements were gradually decreased when the stroll was rotated toward the film, but slightly increased and then decreased when the skull was rotated toward the focal spot. However, the changes were smaller in focal direction. 4. The projection errors of horizontal linear measurements were larger than those of vertical linear measurements. 5. The projection errors of vertical linear measurements were increased with increased distance from the rotation axis to vertical measurements. It is concluded that the use of angular measurements rather than linear measurements is recommended to minimize the projection errors.