• Journal of Welding and Joining
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• v.11 no.3
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• pp.10-21
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• 1993

용접공정에 시각센서를 도입하여 고정 오차, 용접물 준비 상태에 상관없이 유연성을 확보할 수 있고 용접부 형상에 따라 용접 변수를 조절하는 적응제어가 가능하다. 본 해설에서는 용접 자동 화에 이용되는 시각센서의 원리를 설명하였고 상업화되어 쓰이고 있는 시각센서들을 소개하였다. 시각센서를 용접 공정에 적용하기 위해 센서의 신뢰도 향상, 센서와 로봇간의 정보 교환, 용접환 경으로부터 센서의 보호기술등의 개발이 요구됨을 알 수 있었다. 지난 10여년간 용접자동화에 기 계시각을 도입하고자 하는 연구가 활발히 진행되어 자동차, 항공기, 원자력 발전 설비 등의 생산 현장에서 시각센서의 우수성이 입증되고 있다. 현재 접촉식 센서나 아크센서에 비해 가격이 높은 단점이 있어 상업화에 어려움이 있으나 필요 부품들의 계속적인 가격 하락으로 점차 시각센서의 이용이 증대될 것이다. 특히, 아크센서로는 추적할 수 없는 박판 용접과 레이저 용접등의 정밀 용 접공정에서 수요가 커질 것으로 예상된다.

• Journal of Environmental Science International
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• v.20 no.10
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• pp.1233-1241
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• 2011

The main objective of this experimental investigation was $CH_4$ recovery from biogas generated in municipal and wastewater treatment plant. The polysulfone hollow fiber membrane was prepared in order to investigate the permeation properties of $CH_4$ and $CO_2$. Permeability of $CO_2$ in Polysulfone membrane was 11-fold higher than of $CH_4$ gas. A membrane pilot plant for upgrading biogas was constructed and operated at a municipal wastewater treatment plant. The raw biogas contained 66 ~ 68 Vol % $CH_4$, the balance being mainly $CO_2$. The effect of the operating pressure of feed and permeate side and feed flowrate on $CH_4$ recovery concentration and efficiency were investigated with double stage membrane pilot plant. The $CH_4$ concentration in the retentate stream was raised in these tests to 93 Vol % $CH_4$.

• Journal of the Korean Arthroscopy Society
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• v.2 no.1
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• pp.97-100
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• 1998

The giant cell tumor of tendon sheath is very rarely present inside the knee joint. The authors report a case of intraarticular giant cell tumor of tendon sheath arising from posterior cruciate ligament which was successfully excised arthroscopically using posterior trans-septal portal at the time of arthroscopic reconstruction of anterior cruciate ligament.

• Microbiology and Biotechnology Letters
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• v.21 no.2
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• pp.181-186
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• 1993

The functions of n-alkane inducible genes, ALI1 and POX18Cm isolated from Canida maltosa were investigated, using it's distruptants. As a result, it is suggested that ALI1 is essential for n-alkane assimilation in C. mltosa and it regulates genes related to assimilation of n-alkane (ALI1, P450alk POX18Cm) at transcriptional level. Nuclear localization experiments indicated that ALI1 was located and functioned in the nucleus. POX18Cm is considered as a peroxisomal nonspecific lipid transfer protein gene related to n-alkane assimilation in C. maltosa also regulated by ALI1. But it had no significant effect on n-alkane assimilation in C. maltosa.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1471-1475
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• 1987

This paper proposes testable design of sequential NMOS PLAs. The extra bit lines and devices are added to the conventional PLAs. The time is taken to assigning devices in the extra bit lines, which is excessive in the conventional method, is reduced by using the symmetrical distance matrix of the PLA and the regular assigning method. As a result, the test patterns can be easily generated. Also, the silicon area overhead of extra hardware is low.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.467-469
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• 2000

This paper describes an application of discrete wavelet transform for power transformer protection. It is shown that the moving wavelet coefficients method based feature extraction for discrimination between actual internal faults and energizing state. The simulations of power transformer have been carried out using EMTP. The proposed method is more effectively and simpler to distinguish internal faults from inrush currents.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.151-152
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• 2006

Because power plant faults have severe effects on the power system and on mechanical maintenance of the generator, reliable protection systems are needed. In this paper, we compared and analyzed methods of the generator protection relaying system, which can defect internal faults of the generator, and surveyed the trends in generator protection using digital computing.

• Proceedings of the KIEE Conference
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• 2006.11a
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• pp.402-404
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• 2006

In this paper, we simulated transient-state under fault in stator windings of synchronous generator. The fault types are line to ground fault, line to line short fault, and three phase short fault. For fault analysis of generator system, the voltage equation of a synchronous machine using the two-axis theory was used. It can be used to analyze important features of faults and to develop enhanced protection methods.

• Annual Conference on Human and Language Technology
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• 2018.10a
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• pp.69-74
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• 2018

최근 빅 데이터와 인공지능의 발달과 함께 감성 분석에 대한 연구가 활발해지고 있다. 더불어 감성 분석을 위한 긍/부정 어휘가 풍부한 텍스트 문서들에 대한 수집의 필요성도 높아지고 있다. 본 논문은 긍/부정어휘가 풍부한 텍스트 문서들을 수집하는 기존의 수집 방법에 대한 문제점에 대하여 해결방안을 제시한다. 기존의 수집 방법으로 일단 모든 URL들을 저장하고 필터링 과정을 거쳐 긍/부정 어휘가 풍부한 텍스트 문서들을 수집하고자 한다면 불필요한 텍스트 문서 저장과 필터링 과정에서 메모리와 시간을 낭비하게 된다. 기존의 수집 방법에 블룸 필터라는 자료구조를 적용시켜 메모리와 시간을 낭비하게 되는 문제점을 해결하고자 한다.

• Journal of the Korean Ceramic Society
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• v.31 no.2
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• pp.213-219
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• 1994

The formations of spinel and colors of ZnO-Fe2O3-TiO2-SnO2 system have been researched on the basis of ZnO-Fe2O3 system. Specimens were prepared by substituting Fe3+, with Ti4+ or Sn4+ when mole ratios between Fe3+ and Ti4+ or between Fe3+ and Sn4+ were 0.2 mole. The reflectance measurement and X-ray diffraction analysis of the formation of spinel and the colors of there specimens were carried out. ZnO-Fe2O3 system in which Fe2O3 was substituted with SnO2 and TiO2 was formed the spinel structure of 2ZnO.TiO2, 2ZnO.SnO2, ZnO.Fe2O3. The stable stains which were colored with yellow and brown could be manufactured.