• Textile Coloration and Finishing
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• v.30 no.2
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• pp.70-76
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• 2018

The dyeing behaviors of poly(ethylene terephthalate)(PET) bulky yarns, DTY(draw textured yarn) and SSY(latent crimped yarn), were investigated with different energy type disperse dyes compared with those of SDY(spin draw yarn). The maximum exhaustions of E-type disperse Red 60, Blue 56 and Yellow 54 on SSY were 99%, 94% and 93%, respectively. The maximum exhaustions of S-type disperse Red 179, Blue 79 and Orange 30 on SSY were 96%, 97% and 97%, respectively. The K/S values of SSY were significantly higher than those of DTY and SDY in all energy type of disperse dyes. The knit fabric composed of SSY became bulky at the end of high temperature dyeing process because of their thermal shrinkage property due to melt viscosity difference.

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.1
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• pp.96-105
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• 1994

Cup drawing tests were performed to evaluate the friction characteristics of sheet metals. The linear relationship between drawing force and blank holding force obtained from the cup drawing test was used to calculate the coefficient of friction of the sheet metal. The friction coefficient was compared to that from conventional draw bead friction test. It was clarified that the cup drawing test can be used as a simple and convenient method for evaluating the friction characteristic of the sheet metal and also lubricity of the lubricant used.

• Journal of Power Electronics
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• v.9 no.3
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• pp.403-409
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• 2009

Automatically tuned passive filters can improve power quality to a great extent in power systems. A novel three-phase shunt auto-tuned filter is designed to effectively compensate source current harmonics and to provide reactive power required by the non-linear load, which draws a highly reactive, harmonic-rich current from the supply. An artificial neural network (ANN) based controller selects filter component values in accordance with reactive power requirement and harmonic compensation. Traditional passive filters are permanently connected to the system and draw large amounts of source current even under light load conditions. By using auto-tuned filters, the passive filter components can be controlled according to load variations and, hence, draw only required source currents. The selection is done by the ANN with the help of a properly tuned knowledge base to provide instantaneous compensation using a digital controller.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.1
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• pp.19-25
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• 2000

This paper describes the sheath induced voltage in underground transmission cable system which will be operated with cable cover protection unit(CCPU). Simulation was carried out to analyze the sheath induced voltage in the real cable system which was installed by 154㎸ CV cable in the case with and without CCPU. The sheath induced voltage will be also analyzed according to the change of grounding method, fault resistance and fault angle. Simulation was performed using EMTP and ATP Draw, the simulation results show whether the CCPU in necessary or not in underground transmission power cable system.

• The Korean Journal of Rheology
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• v.4 no.2
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• pp.148-160
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• 1992

폴리프로필렌(PP)과 폴리에틸렌(PE)혼합물의 용융방사에 있어서 불안정성을 연구하 였으며 혼합물의 유변학적 성질, 혼합물의 형태학적 특성과 연신공명과의 관계를 고찰한 것 이다. 신장점도는 spinline rheometer를 사용하여 측정하여 섬유직경은 광센서를 이용하여 방사공정에서 on-line 측정하였고 연신공명의 주기는 Fourier 변환을 이용하여 분석하였다. PP와 PE혼합물의 용융방사에 있어서 PP 함유량이 많을수록 연신공명이 발생하는 임계연신 비가 줄어들고 그 주기는 길어진다. 정상상태에서 구한 유변학적 성질을 이용하여 Shah와 Pearson의 이론식과 Fisher와 Denn의 이론식으로부터 구한 임계연신비값이 실험치와 많은 차이를 보여주었다. 연신공명에 의하여 형성된 섬유의 가는 부분의 배향도는 굵은 부분에 비하여 크게 향상되었으며 PP 함유량이 많을수록 배향도가 크게 증가하였다.

• Transactions of Materials Processing
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• v.16 no.5 s.95
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• pp.364-369
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• 2007

The effect of temperature on the forming limit diagram was investigated for AZ31B magnesium alloy sheet through the limit dome height test in the range from room temperature to $300^{\circ}C$. The formability of AZ31B sheet was improved significantly according to the increasing temperature. Also we studied the springback characteristics through the 2D draw bending test with different blank holding forces at elevated temperatures. Springback quantity was considerably reduced as temperature went up. The blank holding force in the range used, however, had little influence on springback. Experimental results obtained in this study may provide a material database for AZ31B sheet.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.737-744
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• 2000

This paper resorts to rock mass rating and rock mass quality to draw value based on the evaluation of rock and to draw interrelation formula in relation to rock mass quality, A comparative analysis was given of survey values reported in the existing documents. This paper has tried to find out the relationship between RMR and Q System for the sake of choosing rational reinforcing patterns and of the safety of tunnels. The results run as follow: RMR=8.251n(Q)+43.83. This paper has also tried to find out the relationship between RMR and Q System by using Fuzzy Approximate Reasoning Concept. We suggest that those in charge should not depend on a single system only after evaluating the classification of rocks, and compare one result with another for the good of keeping track of the condition of base rocks in a better way.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.730-733
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• 2001

A computer aided design system for spur, helical, bevel and worm gears by using AutoCAD system and its AutoLISP computer language was newly developed in this study. Two methods are available for a designer to draw a gear. The first method needs the gear design parameters such as pressure, module, number of tooth, shaft angle, velocity, materials, etc. When the gear design parameters are inputted, a gear is drawn in AutoCAD system and maximum allowable power and shaft diameter are calculated additionally. The second method calculates all dimensions and gear design parameters to draw a gear when the information such as transmission, reduction ratio, rpm, materials and pressure are inputted. The system includes four programs. Each program is composed of a data input module, a database module, a strength calculation module, a drawing module, a text module and a drawing edit module. In conclusion, the CAD system would be widely used in companies to find the geometric data and manufacturing course.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1705-1708
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• 2003

The purpose of this study is to investigate the manufacturing technique on the U type Draw-Bending of inner grooved tube. This bending process make the U shape tube by Hair Pin Bending machine. The U type tube requires the quality of product that satisfy sufficient conditions for a heat exchanger. The mandrel components act the important roles that prevent wrinkles and keep the shape of cross section of bended tube at bending process. We performed the FEM simulation using LS-DYNA software and the bending test of inner groove tube and then, compared bending simulation with bending test results about mandrel ball diameter, mandrel position and optimal clearance between mandrel and tube.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.6
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• pp.1474-1486
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• 1990

The frictional characteristics of galvanized sheet steels(GA, EG, EGF, EGN) for automobiles were studied and compared with that of cold rolled sheet steel. A draw bead tester which simulates metal flow through a draw bead in stamping die face was used to measure coefficients of friction of galvanized sheet steels for four kinds of lubricants. Stamping formability of galvanized sheet steels for quarter outer panel was examined. The results show that stamping formability and friction characteristics were mainly influenced by the nature of zinc coating, surface roughness and micro hardness of coated layer, and proved to be very sensitive to the lubricant used.