• Ocean Systems Engineering
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• 제8권2호
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• pp.101-118
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• 2018

In case of conventional shallow-draft semisubmersibles, unacceptably large riser stroke was the restricting factor for dry-tree-riser-semisubmersible development. Many attempts to address this issue have focused on using larger draft and size with extra heave-damping plates, which results in a huge cost increase. The objective of this paper is to investigate an alternative solution by improving riser systems through the implementation of a magneto-rheological damper (MR Damper) so that it can be used with moderate-size/draft semisubmersibles. In this regard, MR-damper riser systems and connections are numerically modeled so that they can couple with hull-mooring time-domain simulations. The simulation results show that the moderate-size semisubmersible with MR damper system can be used with conventional dry-tree pneumatic tensioners by effectively reducing stroke-distance even in the most severe (1000-yr) storm environments. Furthermore, the damping level of the MR damper can be controlled to best fit target cases by changing input electric currents. The reduction in stroke allows smaller topside deck spacing, which in turn leads to smaller deck and hull. As the penalty of reducing riser stroke by MR damper, the force on the MR-damper can significantly be increased, which requires applying optimal electric currents.

• The Journal of Asian Finance, Economics and Business
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• 제7권11호
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• pp.801-808
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• 2020

The purpose of the study is to find the factors that influence the financial leverage of Vietnam firms. The dependent variable is the financial leverage and the independent variables are firm size, asset structure, liquidity, growth opportunities, profitability, and firm age. The data are collected from Vietnam firms' annual financial reports in the period from 2010 to 2019. The study uses a sample of 448 Vietnam listed firms in the period. We also employ a panel regression model with pooled OLS and fixed effect to analyze the firms' financial data. The results of the model showed that financial leverage (FL) has a negative relationship with some factors such as asset structure (AS), liquidity (LQ), growth opportunities (GRW), profitability (ROA), and firm age (AGE) in the fixed effect regression. It means that when liquidity, profitability, and firm age increase, firms' financial leverage will decrease. While firms' financial leverage has still a positive relationship with the firm size (SIZE) in the model. As a result, when firm size increases, financial leverage will increase, too. The results showed that models are fit for the research and can be used to predict future findings. It is also useful for enterprises, financial advisors, investors, as well as the financial managers.

• 한국전기전자재료학회논문지
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• 제31권4호
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• pp.193-197
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• 2018

The ratio of the period of a diffractive element to the input beam size is a critical parameter in a diffractive beam shaper. We measured and calculated the Fraunhofer diffraction patterns of a periodic hologram with an input beam size similar to the period of the hologram. The measured intensities show very complicated patterns and are strongly dependent upon the center position of the laser beam relative to the hologram. Using a diffraction formula for a periodic hologram, we calculated the diffracted light intensities and fit them to the measured ones. The measured and calculated intensities are in good agreement even when the beam diameter of the incident laser is similar to the period of the hologram. We can therefore use this formula to estimate the output of a periodic beam shaper even under such an extreme condition.

• 패션비즈니스
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• 제25권5호
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• pp.88-98
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• 2021

In this study, the characteristics of digital anthropometric methods were determined with case studies. These methods were broadly classified into two categories: non-wearable and wearable. Then, these categories were further classified into four types: 3D Scanning, mobile app, smart clothing, and smart tool Among the non-wearable types, the "3D scanning" technique was based on the use of 3D hardware equipment. With this technique, the body shape was measured and the internal body information was obtained. Therefore, it is used in fields of healthcare and fitness. Among the wearable types, "Smart clothing" involves a special clothing that measures human body and a smartphone application. Both the components are linked to a fashion platform, which is based on the measured sizes that help shoppers. The "Smart tool" has the characteristic of measuring only with smart tools and smartphone applications; it does not involve the measurement of images. The common advantage of digital anthropometric methods are as follows: they reduce the time and cost of measurement by enabling self-measurement. Moreover, simple measurements are used to determine the size of anthropometry. Thereafter, it accumulates this data to track the continuous changes in size. From an industrial point of view, digital anthropometric technology should be used to increase sales. The on-demand market can be expanded as global consumers would throng the Korean fashion market. For the consumer, an avatar should be created to fit the user's size. This would provide a fun experience to the user.

• Structural Engineering and Mechanics
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• 제84권3호
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• pp.337-344
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• 2022

Due to corrosion defects on the surface of the oil pipe, the sealing performance of the annular blowout preventer (BOP) decreases, and the leakage of toxic and harmful gases such as H₂S and SO₂ will threaten the safety of operators on the well. Therefore, this paper establishes the FE model for evaluating the sealing performance of BOP-oil pipe corrosion defects, which is based on the rubber large deformation theory and rubber core sealing mechanism, and designs the experiment of BOP sealing performance to verify the accuracy of the FE model. The sealing performance of BOP sealing oil pipe with corrosion defects is studied. The research results show that the sealing performance of BOP is more sensitive to the axial size of corrosion defects. With the increase of oil pipe outer diameter, the critical size of defects increases continuously. The sensitivity of radial and depth dimensions is low, When for 88.9 mm outer diameter oil pipe, the axial critical size of corrosion defect is 20 mm, the radial critical size is 16 mm and the critical depth is 2 mm. Fit the formula between the outer diameter of oil pipe and the piston increment. According to the formula, the operator can calculate the piston stroke increment required by the BOP to complete the sealing when the oil pipe is corroded.

• 한국의류학회지
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• 제33권11호
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• pp.1768-1773
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• 2009

This study determines the body size of preteen children and conducts questionnaire investigations into the awareness of real purchasers or parents of and satisfaction with children's clothes and fit, in order to provide the basic data for planning and setting up the size range for the preteens market in which the sales of children clothes are gradually increasing. The findings of this study are as follow: Analyzing the obesity of the children against the Rohrer index showed that almost 30% of the subjects were obese children and that it is necessary to research the sizes of the clothes for obese children. It was also found that older children selected a more appropriate clothe size. Investigations into the awareness of children on their body image found that there was a significant difference in the perception of body shape, body weight, shoulder breath, arm thickness, chest girt, waist girth, hip girth, and thigh thickness. Slim or standard type children had the greatest consideration for the length of clothes to purchase while obese children had the greatest consideration for bosom size and waist girth. However, in terms of the association between fitness and size selection, obese children did not select a bigger size but an appropriate one for their body. The findings show that it is imperative to develop appropriate size clothes for obese children.

• 한국광물학회지
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• 제21권2호
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• pp.201-208
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• 2008

최근 기능성 나노물질로서 반도체 공정 중 기계.화학적 평탄화(CMP)용 연마제로 중요하게 사용되는 세리아(Ceria, $CeO_2$)에 대해서 X-선 회절분석을 실시하여 리트벨트법에 의한 상세한 구조해석 및 세리아의 입자크기와 미세응력을 측정하였다. 두 시료(RT735. RT835)의 리트벨트 계산 결과 R지수 값은 각각 $R_p(%)=8.50$, 8.34; $R_{wp}(%)=13.4$, 13.5; $R_{exp}(%)=11.3$, 11.5; $R_B(%)=2.21$, 2.36; S(GofF: Goodness of fit)=1.2, 1.2를 보여주며 계산이 잘 이루어졌음을 알 수 있다. $CeO_2$는 공간군 Fm3m을 가지며, 격자상수는 a=5.41074(2), 5.41130(6) ${\AA}$, V=158.406(1), 158.455(3) ${\AA}^3$으로 각각 계산되었다. 입자크기 및 미세응력 계산 결과, RT735의 평균 입자크기와 최대 응력은 37.42(1) nm, 0.0026이며, RT835는 72.80(2) nm, 0.0013으로 각각 결정되었다. 입자크기와 미세응력은 서로 반비례함을 알 수 있다.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1998년도 춘계학술대회논문집
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• pp.13.2-18
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• 1998

The purpose of this study was to investigate the attitude related to the purchasing and wearing dress shoes for Korean adult women. 480 adult women age from 18 to 86 years participated in the survey and they were recruited in Seoul and Taejeon. The results were as following; 1. The most common dress shoes sizes were 235 and 240. 2. The subjects age uder 30 years perceived that the fashion is mor important than the comfort when they purchase dress shoes. The suvjects age over 60 years preferred shoes design giving comfort than fashionably designed one. 3. The most frequent complainings with dress shoe design were narrow shoe width, the stiffness of material, and discomfortable sole shape. 4. The letter size designation of dress shoes was not fulled recognized by the consumers. The use of letter size designastion was extremely low when they purchased shoes that fit their foot.

• Journal of Magnetics
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• 제21권3호
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• pp.374-378
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• 2016

The transformer used in an inverter type arc welding machine is designed to use high frequency in order to reduce its size and cost. Also, selecting core materials that fit frequency is important because core loss increases in a high frequency band. An inrush current can occur in the primary coil of transformer during arc welding and this inrush current can cause IGBT, the switching element, to burn out. The transformer design was carried out in $A_P$ method and amorphous core was used to reduce the size of transformer. In addition, sheet coil was used for primary winding and secondary winding coil considering the skin effect. This paper designed the transformer core with an air gap to prevent IGBT burnout due to the inrush current during welding and proposed the optimum air gap length.

• 복식문화연구
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• 제6권4호
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• pp.175-187
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• 1998

Hats are an important part of the fashion accessory business and Their importance is increasing year by year. Their importance is increasing not only as a means of accessory ut also as a means of sportswear due to the leisure-sports boom of the 90's. As hats are becoming more and more popular and ready-made, demand for comfortable and easy-fitting hats are increasing. Being an piece of apparel, fitting is very important factor in hats as well s in other forms of clothing. But many hat-wears complain of dissatisfaction of fitting of their hats. In addition to this, another problem is hat most hat designs have been flown in from the West without inspection of their fits. Designs to fit the Koran face and head have not been developed properly. This study is based on the need for the development of a well-fitting hat pattern design for Korean young women. After taking actual measurements of 170 young womens, a size system was organized for developing patterns for different size groups.