• Journal of the Korean Society of Industry Convergence
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• v.25 no.4_2
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• pp.637-644
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• 2022

In this study, the flow characteristics according to the shape of the vortex nozzle was studied by numerical analysis and the amount of microbubble generation was measured experimentally. The shape of the vortex nozzle is cylindrical, diffuser, and conical type. The axial fluid velocity in the induced tube gradually increased from the inlet to the outlet. In particular, the fluid velocity in the nozzle part increased rapidly. The velocity distribution of the fluid at the inlet of the induced tube showed that the flow rotates counterclockwise in the outer region and the inner center of the induced tube. At the outlet of the induced tube, the cylindrical and conical type showed rotational flow, and the diffuser type showed irregular turbulent flow. The dimensionless pressure ratio 𝜂 of the inner region of the induced tube was lower than that of the outer region. Also, 𝜂 near the outlet of the induced tube in cylindrical and conical type showed a similar tendency to the inlet area. At the outer region of inlet of induced tube, intense vorticity was observed on the wall and in lower region. At the inner region of inlet of induced tube, intense vorticity was observed on the inner wall of the induced tube and in the central region of the inlet of the induced tube. At the outlet of induced tube, in the case of the cylindrical and conical type, intense vorticity was observed near the inner wall, the diffuser type showed irregular strong vorticity inside the tube. The total number of bubbles measured was the most in the cylindrical type, and the microbubbles less than 50mm occurred the most in the conical type.

• Journal of the Earthquake Engineering Society of Korea
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• v.28 no.6
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• pp.355-364
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• 2024

Recently, high-rise residential buildings in Korea have adopted slender shear walls with irregular section shapes, such as T-shape, H-shape, and C-shape. In the seismic design of the slender shear walls, the transverse reinforcement for lateral confinement should be provided in the boundary elements to increase deformation capacity and subsequent ductility. However, in practice, the irregularity of the shear walls is not adequately considered, and the lateral confinement region is calculated for the rectangular wall segments. This study investigated the proper design method for lateral confinement regions using finite element analysis. The lateral confinement region was considered in analysis for two cases: 1) as a typical rectangular wall segment and 2) as an irregular wall. When the irregularity of the walls was considered, the compression zone depth was increased because the vertical reinforcement in the flange was addressed. The effect of lateral confinement design methods on the structural performance of the walls was directly compared under various design parameters, including the length of the flange, concrete compressive strength, vertical rebar layout, axial load ratio, and loading direction. According to the results of the parametric analysis, the peak strength and deformation capacity could be significantly increased when the lateral confinement region was calculated based on irregularly shaped walls, regardless of the design parameters. In addition, the effective compression zone was located within the lateral confinement region. Thus, it is recommended that the lateral confinement region of T-shaped walls is calculated by addressing the irregularity of the walls.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1573-1575
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• 2004

An alumina membrane with nano-sized pores was fabricated by anodic oxidation. The shape and structure of the pore on alumina membrane were changed according to the roughness of aluminum surface. The shape and structure of the nano-sized pre were investigated according to purity of aluminum substrate for the anodization process. The aluminum substrates with 99.5% and 99.999% purities were used. The aluminum substrate(99.5%) was anodized after the processes of pressing, mechanical polishing, chemical polishing, and electrochemical polishing. The nano-sized pores with the pore size of 50 - 100nm, the cell size of 20-50nm and the thickness of $10{\mu}m{\sim}45{\mu}m$ were obtained. Even though the electrochemical polishing was used for the aluminum substrate (99.999%), the same characteristics as the aluminum substrate (99.5%) was obtained. The alumina membrane prepared by anodization for 5 min using fixed voltage method shows the pore with irregular shape. The pore shape was changed to regular shape after pore widening process.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.30 no.2
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• pp.39-50
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• 2018

In this study, the nonlinear interaction of irregular waves with wave breaking and currents around permeable submerged breakwater was investigated with the aid of olaFlow model which is open source CFD software published under the GPL license. The irregular wave performance of olaFlow applied in this study was verified by comparing and evaluating the target frequency spectrum and the generated frequency spectrum for applicability to irregular waves. Based on the applicability of this numerical model to irregular wave fields, in the coexistence fields of irregular waves and currents, the characteristics of wave height, frequency spectrum, breaking waves, averaged velocity and turbulent kinetic energy around porous submerged breakwater with the respect to the beach type and current direction versus wave propagation were carefully investigated. The numerical results revealed that the shape of wave breaking on the crown of the submerged breakwater and the formation of the mean flow velocity around the structure depend greatly on the current directions and the type of the beach. In addition, it was found that the wave height fluctuation due to the current direction with respect to the wave propagation is closely related to the turbulent kinetic energy.

• The Journal of Korean Medicine
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• v.18 no.1
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• pp.430-445
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• 1997

In order to know the effects of Calculus $Bovis{\cdot}F디$ Ursi aqua-acupuncture ($C{\cdot}F$ aqua-acupuncture) to the liver damage, we carried out the treatment of $C{\cdot}F$ aqua-acupuncture and injection of Kam-Du-Tang on the liver damaged rat which is induced by aconitine, and then ultrastructural study has been to the liver tissue. The results were as follows: 1. In the hepatic cell of normal group, the nuclear envelope is round and electro-density of nucleoplasm is relatively low, and have one or two large nucleolus. Cell organelle is developed rough endoplasmic reticulum(RER) and many mitochondria, glycogen granules, smooth endoplasmic reticulum(SER) and Golgi apparatus. 2. In 24 hours control group, nuclear envelope is very irregular, RER and most of cell organell is shown that destroyed by aconitine. This is similar to the 48 hours control group. In 72 hours control group, RER is recovered somewhat but cristae of mitochondria is not seen the shape 3.In 24 hours $C{\cdot}F$ aqua-acupuncture group, nuclear envelope is very irregular and cristernae is very dilatable and many mitochondria is dilationed and the cristae is not definite like the control group. In 48 hours $C{\cdot}F$ aqua-acupuncture group, nuclear envelope is relatively round and chromatin is regular. Cristernae of RER and ribosme is somewhat imperfect but is similar the normal group, and the cristae of mitchondria is shown definitely like the normal group. In 72 hours $C{\cdot}F$ aqua-acupuncture group, nuclear envelope is round and cell organell is similar to normal group. 4. In 24 hours Kam-Du-Tang group, nuclear envlope is very irregular and cell organelles are destroyed by the effects of aconitine. In 48 hours Kam-Du-Tang group, nuclear envelope is somewhat irregular but chromatin is relatively regular. RER is seperated regularly through the cytoplasm, but cannot make the structure of lamina, and cistennae is very dilationed. many of glycogen granules is seperated regularly. In 72 hours Kam-Du-Tang group, RER makes the lamina. Mitochondria is a little but inner space is dilationed so the shape of is not definite and a lot of glycogen granules are accumulated in several places. It see the above result, hepatic cell that is damaged by aconitine is effected chiefly by the $C{\cdot}F$ acupuncture and effect of acupuncture is similar to the detoxicated effect of Kam-Du-Tang.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.6
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• pp.545-551
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• 2017

It is very important to effectively obtain the information related to the human body shape for user-centered design. The human body shape is a huge combination of various irregular curves and is typically obtained by a 3-D Scanner. 3-D scanners show high reliability; however, they are expnsive equipment with limited mobility. 3-D models of irregular-shaped curves were created by a photogrammetric approach and the errors between the original curve and the models were evaluated. 3-D models were created based on 160, 80, 40, 20, 10, and 5 marking points evenly located on the original curve. In the case of convex curve, low levels of residuals were observed in the models from 160, 80, 40, and 20 marking points (0.13% max). In the combination of convex and concave curves, relatively low levels of residuals were observed in the models from 160, 80, and 40 marking points (0.29%). It is possible to conclude that marking points should be placed at every 5% of overall length of a convex curve and at every 2.5% of overall length of a curve with convex and concave curve in order to maintain low levels of errors. A photogrammetric approach can be used as an alternative for the 3-D scanners with advantages of low cost and mobility.

• Journal of Korean Society of Forest Science
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• v.79 no.4
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• pp.407-412
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• 1990

Morphological characters on the leaf nectar gland of Korean Prunus 4 species and 1 form were observed by SM. The results were summarized as follows ; The shapes of nectar gland on the plane figure were two, the circular and the irregular ovate. The species of circular shape were P. maackii, P. maximowiczii, P. sargentii and P. yedoensis. The irregular ovate shape was only one species, P. pendula for. ascendens. The shapes of nectar gland on the side figure were the reentrant apices and the rounded. The reentrant apices were two shapes. First, the species of the center reentrant was three, P. maackii, P. sargentii and P. yedoensis. Second, the species of the irregular reentrant was P. pendula for. ascendens. The rounded apex was only one species, P. maximowiczii. Especially on the P. pendula for. ascendens, the upheaval situation on surface of leaf blade was due to the sinking of reverse part of leaf blade at the nectar gland. The point of this abnormal shape was well distinguished from the other species. On the frequency by the part of leaf with nectar gland, the species to be observed only at the leaf base was P. pendula for. ascendens, the other species was observed two part of leaf base and petioles. In this study, some Prunus species were well keyed out on the basis of the morphological characters of leaf nectar gland.

• Tribology and Lubricants
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• v.22 no.5
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• pp.276-281
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• 2006

The fractal dimension is quantitatively to define the irregular characteristic of the shape in natural. It can be useful in describing morphological characteristics of various wear particles. This paper was undertaken to diagnose failure condition for sliding members in lubrication by fractal dimension. It will be possible to diagnose wear mechanism, friction and damage state of machines through analysis of shape characteristics for wear particle on driving condition by fractal parameters. In this study, the calculating and analyzing methods of fractal dimensions were constructed for the condition monitoring and wear particle analysis in lubricant condition. So, we carried out the Friction and wear test with the ball on disk type tester, and the fractal parameters of wear particle in lubricated conditions were calculated. Fractal parameters were defined as texture fractal dimension ($D_{t}$), structure fractal dimension ($D_{s}$) and total fractal dimension (D).

• The Research Journal of the Costume Culture
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• v.15 no.6
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• pp.1008-1022
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• 2007

The purpose of this study is to propose apparel sizing system for each body shape of early adolescent boys. The subjects of this study were 549 boys in the capital area. Their body shapes were classified and apparel sizing system was proposed for each body shape. For data analysis were performed descriptive statistics, correlation analysis and crosstabulation using SPSS Ver. 12. The control dimensions to propose apparel sizing system were stature and bust circumference for the upper garments. Intervals between sizes were 5cm for stature and irregular for bust circumference. For each type, $5{\sim}7$ sizes were proposed for upper garments. Reference measurements suggested for upper garments were 9 items. This study is meaningful in that it classified early adolescent boys' body shapes and proposed apparel sizing system for each type of body shape under the current circumstances where basic data for body shape classification and apparel sizing system of early adolescent boys were not in place.

• Agricultural and Biosystems Engineering
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• v.6 no.2
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• pp.70-76
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• 2005

Seed, stem and sprout of F. tataricum were separately milled using the ultra fine mill under the same condition to investigate the effect of roasting or extruding on the particle size, microstructure and water solubility of dietary fiber. The mean particle size of MR (roasting) is increased in stem and sprout, and that of ME (extruding) is increased in seed, compared to that of control. The microscopic views of seed show that control has the spherical shape but ME the larger and irregular shape, and those of stem and sprout show that control has the needle like shape but ME more rounded shape. Water solubility index of ME is much higher than that of control or MR in seed, stem and sprout. It shows that seed, stem and sprout are damaged more in extruding than in roasting, and the starch and cell wall structure must be destroyed to change the water insoluble dietary fiber into the water soluble dietary fiber.