• Journal of Fashion Business
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• v.18 no.6
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• pp.38-56
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• 2014

This study compared the flared skirts on 3D simulation and in real to show diverse forms in women's clothing depending on the body's gait and motion. By finding the problems, we suggested the possible methods for utilizing the 3D simulation in the clothing industry. First, the 3D simulation of flared skirts showed similar forms of appearance according to the flare length and volume. However, virtually formed drape shape was even in size and spacing, whereas it was not even in real. Second, according to the results of appearance test on the length and flare volume at $90^{\circ}$ and $180^{\circ}$, both real and 3D simulation skirts were evaluated to have outstanding appearances regardless of the skirt length. However, as the flares volume increased, the skirts with longer length were evaluated to have superior appearances compared to the skirts of shorter length. Third, it showed higher resemblance between the real and virtual simulation, when the skirt had less flare and as the skirt length shortened. However, it showed greater difference between the real and virtual simulation when flare volume and length increased. The length and volume of the skirt and the physical properties of the material are predicted to be different between the real and virtual simulation. However, they usually are similar in forms, so it is believed possible to use for predicting the design's silhouette or the feel when it is worn. This method can be applied on internet shopping malls, which can possibly reduce unnecessary time and expenses.

• Journal of Korean Society on Water Environment
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• v.35 no.1
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• pp.64-71
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• 2019

In recent years, carbon dioxide ($CO_2$) bubbles emerged as the most widely applied material with the recycling of sequestrated storage to decrease global warming. Flotation using $CO_2$ as an alternative to air could be effective in overcoming the high power consumption in the dissolved air flotation (DAF) process. The comparison of DAF and DCF system indicated that, the carbon dioxide flotation (DCF) system with pressurized $CO_2$ only requires 1.5 ~ 2.0 atm, while the DAF system requires 3.0 ~ 6.0 atm. In a bid to understand the characteristics of particle separation, the single collector collision (SCC) model was used and a series of simulations were conducted to compare the differences of collision and flotation between $CO_2$ bubbles and air bubbles. In addition, laboratory experiments were sequentially done to verify the simulation results of the SCC model. Based on the simulation results, surfactant injection, which is known to decrease bubble size, cloud improved the collision efficiency of $CO_2$ bubbles similar to that of air bubbles. Furthermore, the results of the flotation experiments showed similar results with the simulation of the SCC model under anionic surfactant injection. The findings led us to conclude that $CO_2$ bubbles can be an alternative to air bubbles and a promising material as a collector to separate particles in the water and wastewater.

• Transactions of Materials Processing
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• v.9 no.5
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• pp.533-538
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• 2000

This study has been carried out to develop a CRT die using hot forging. The conventional CRT die made by casting has defects such as void and inclusion. These defects of the cast die make micro-spots on the surface of the CRT which affect the quality of the final product. So, a hot forging process is developed to avoid these defects of CRT die by the model material test and the rigid-plastic FEM. Firstly, model material tests are carried out with plasticine billets in order to investigate the material flow pattern in the die cavity and to get the reasonable initial values for designing the preform in the FE simulation. And then a finite element analysis has been performed to Predict the preform and the forging load of a CRT die. We also suggest an integrated die-set which combines two die-sets into one die-set to save manufacturing time and cost in case of similar die-size.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.184-187
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• 2000

In this paper, a ring-type ultrasonic motor divided into 12 sectors was modeled by Atila program using finite element method(FEM). The stator consists of a piezoelectric ceramic poled alternately in opposite directions and elastic material. And the stator dimension was $\Phi$40 (outer diameter), $\Phi$ 30(inner diameter), 0.5mm(ceramic thickness) and 3mm(elastic material thickness). As a simulation result, 6$\lambda$ displacement occurred at approximately 52kHz, and this resonance frequency is similar to calculated result 57kHz. The position of maximum displacement was at the edge of stator.

• Structural Engineering and Mechanics
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• v.36 no.4
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• pp.481-497
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• 2010

The shaking table tests were conducted on two small-scale models (Model 1 and Model 2) to examine the earthquake-induced damage of a concrete gravity dam, which has been planned for the construction with the recommendation of the peak ground acceleration of the maximum credible earthquake of 0.42 g. This study deals with the numerical simulation of shaking table tests for two smallscale dam models. The plastic damage constitutive model is used to simulate the crack/damage behavior of the bentonite-concrete mixture material. The numerical results of the maximum failure acceleration and the crack/damage propagation are compared with experimental results. Numerical results of Model 1 showed similar crack/damage propagation pattern with experimental results, while for Model 2 the similar pattern was obtained by considering the modulus of elasticity of the first and second natural frequencies. The crack/damage initiated at the changing point in the downstream side and then propagated toward the upstream side. Crack/damage accumulation occurred in the neck area at acceleration amplitudes of around 0.55 g~0.60 g and 0.65 g~0.675 g for Model 1 and Model 2, respectively.

• Steel and Composite Structures
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• v.21 no.3
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• pp.517-536
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• 2016

Thick steel plate is commonly found with mega steel structures but its properties have not been fully explored. Grade Q345GJ-C steel plate with thickness ranging from 60 mm to 120 mm are studied in this paper. Both the static and cyclic performance of material in different directions (horizontal and through-thickness directions) and locations (outer surface, 1/4 thickness and mid-depth) are experimentally obtained. The accumulative damage during cyclic loading is also calculated by using bilinear mixed hardening (BMH) constitutive relationship together with the Lemaitre's damage model. Results show that the static properties are better at the outer surface of thick steel plates than those at mid-depth. Properties in through-thickness direction are similar to those at mid-depth in the horizontal direction. The cyclic performance at different locations of a given plate is similar within the range of strain amplitude studied. However, when damage parameters identified from monotonic tensile tests are included in the numerical simulation of cyclic loading tests, damage is found accumulating faster at mid-depth than close to outer surface.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.696-700
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• 2007

In case of dome-typed gymnastics training floor, since its form takes shape of the focus of sound, in the occasion when the finishing-material was used with the sandwich panel that prominent in reflexibility, and because the reverberation of sound in indoor is too loud, a smooth practice and teaching is very difficult. As this indoor gymnastics training floor, standing at its character, is required simultaneously the idea communication between the player and the coach, and the acoustic capability regarding to the clearness of music, besides the sport activity, the method to minimize the acoustic defect should be urgently contrived from the stages of design and beginning of construction. On this viewpoint, after investigation on the confidence of the surveyed value and the estimated value using acoustic simulation, and use of the changed finish-material, this thesis intends to design the dome-typed gymnastics training floor that secured the optimized acoustic condition. It is also considered that such result of the study could be utilized as the useful data that enables to improve the retrenchment effect of the construction cost as well as the acoustic performance, by means of the prediction control on the acoustic problem from the stage of design, for the occasion when the similar indoor sport gymnasium is planning to build for the near future.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.22 no.2
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• pp.185-199
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• 2024

Disposal cover as an engineered barrier of a near-surface disposal facility for low and very low-level radioactive waste is composed of a multi-layer to isolate radioactive waste from environmental influences for the long term. To acquire a realistic forecast for the post-closure period of the disposal facility, it is essential to carry out long-term experimental research in a similar condition to the actual disposal environment. Hence, a performance test facility of the disposal cover was constructed in Gyeongju low and intermediate level radioactive waste disposal center in 2022. The constructed performance test facility has differences from the material properties presented in the design. These differences are factors that affect the prevent rainfall infiltration, which is one of the important roles of the disposal cover. Therefore, in this study, a numerical simulation of rainfall infiltration into the performance test facility was performed for the designed case and the actual constructed case. To simulate the behavior of water infiltration, the FEFLOW software based on the finite element method is used. Through the analysis of numerical simulation results, it is confirmed that the hydraulic conductivity of the material constituting the multi-layer of the disposal cover greatly influences the amount of water infiltration.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.12
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• pp.131-137
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• 2004

In this paper, we proposed the method of the characteristic impedance and effective dielectric constant calculations of a parallel-two-wire transmission line coated with multi-layer dielectric material using conformal mapping method. First of all, we calculated the capacitance of the transmission line when coated by N layer dielectric material which has different thickness and dielectric constant and calculated the characteristic impedance and effective dielectric constant using calculated capacitances. When compared with the Maxwell 2D (made by Ansoft Corporation) simulation result calculated result was very similar to the simulation result within the four percent error range.

• Journal of Biosystems Engineering
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• v.25 no.6
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• pp.445-456
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• 2000

A can type high-speed transplanting mechanism was developed. The mechanism consists of a cam and an epicycle gear train with one sun gear in the middle and four planet gears in a row but symmetric with respect to the sun gear. Two planting knives are pivoted on the two outer gears. When sun gear rotates with a constant velocity the planting knife rotates also with a constant velocity. This constant motion of the transplanting knife is accelerated partially by a cam fixed in the gear housing so that the locus of the planting knife becomes similar to that generated by a crank-type transplanting mechanism. This cam-type transplanting mechanism can solve the problems associated with the rotary-type transplanting mechanisms. The mechanism was designed with an aid of computer simulation and proved applicable to high speed transplanters by its mock-up model. The design process of the mechanism was presented and dynamic analysis was also carried out to show the advantages of the mechanism over the rotary type high-speed planting mechanism.