• 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 Korean Society for Information Management Conference
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• 2014.08a
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• pp.221-228
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• 2014

본 연구의 배경은 공공도서관 사인시스템의 현황과 지속적인 활용에 있다. 수많은 정보 중 필요한 정보를 선별하고 수용하는 것이 중요한 현대사회에서 사인시스템은 원만한 상호작용을 위한 주요수단이다. 특히 복잡한 구조와 공간의 기능을 함께 지니고 있는 도서관에서 정보를 파악하기 위해서 명확한 지각효과를 갖춘 사인의 역할은 무엇보다 중요하다. 이에 따라 본 연구는 이용자가 공공도서관을 이용할 때 어떠한 요소가 정보를 수용하고 시각적으로 인지하는데 많은 영향을 미치는지 알아보고자 한다. 그리고 선정된 도서관을 대상으로 기능 및 시각적 요소에 따라 사례분석을 한 후 이용자 만족도 조사를 실시하여 효과적이고 편리하게 도서관을 이용할 수 있도록 정보를 제시하는데 목적이 있다.

• Tuberculosis and Respiratory Diseases
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• v.45 no.1
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• pp.222-226
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• 1998

We report a rare case of primary tracheal malignent melanoma documented by careful clinical examination. Differentiation between primary and metastatic malignant melanoma is very difficult We conclude that this tracheal tumor is a primary malignant melanoma based on characteristic pathologic features and the exclusion of the possibility of spontaneous regression of the primary site by patient's history and physical examination.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.283.2-283.2
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• 2002

Organochlorine pesticides and polychlorinated biphenyls (PCBs) have been used intensively in agriculture and industry for a long time. They belong to a group of contaminants whose occurrence in the environment is a serious concern to environmental chemists and toxicologists due to their resistance to degradation in the environment as well as their potential toxicity. Also. the lipophilic characteristics of these substances are responsible for their ability to bioaccumulate in tissues and organs rich in lipids of men and animals through food chain. Therefore, the measure of the levels of organochlorine pesticides and PCBs in human tissues are good markers in detemining the extent to exposure and evaluating the hazards. This study was preformed to compare concentrations of organochlorine pesticides(${\alpha}-BHC, {\beta}-BHC, {\gamma}-BHC, {\delta}-BHC$, p.p'-DDT,p.p'-DDD,p.p.'-DDE. endrin. dieldrin. aldrin) and seven marker PCBs(PCB nos. 28. 52. 101. 118. 138. 153. 180) in liver. kidney cortex, lung blood and adipose tissue collected at autopsies of 10men and 10 women using gas chromatography equipped with electron capture detector to express the data on a lipid adjusted basis. From the results, the significant differences in the levels of organochlorines of PCBs between sexes, districts where they had lived and ages were also investigated.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.611-616
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• 2001

This paper analyzed PFC of active clamp ZVS flyback converter by adding two methods PFC (power Factor Correction) circuit - two-stage and single-stage. The addition of active clamp circuit also provides a mechanism for achieving ZVS of both the primary and auxiliary switches. ZVS also limits the turn off di/dt of the output rectifier, reducing rectifier-switching loss and switching noise, due to diode reverse recovery. As a result, the proposed converters have characteristics of the reduced switching noise and high efficiency in comparison to conventional flyback converter. The simulation and experimental results show that the proposed converter improve the input PF of 300W ZVS flyback converter by adding single-stage, two-stage PFC circuit.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.969-973
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• 1990

This paper presents a method of suboptimal control for nonlinear systems via block pulse transformation. The adaptive optimal control scheme proposed by J.P. Matuszewski is introduced to minimize the performance index. Nonlinear systems are controlled using the obtained optimal control via block pulse transformation. The proposed method is simple and computationally advantageous. Viablity of the this method is established with simulation results for the van der Pol equation for comparision with other methods.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.440-441
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• 2010

본 논문은 동기 전동기 속도 및 토크 제어를 위해 필요한 전류 센싱 방식들의 특징을 비교분석한다. 동기 전동기 전류 검출 방법 중 가장 많이 사용되는 홀 CT (Current Transducer)를 이용한 방법과 3상 인버터 각 암에 3개의 Shunt Resistor를 통하여 전류를 검출하는 방법을 적용하여 동기 전동기를 벡터제어하고 각각의 장단점을 분석한다. 분석내용을 PSIM을 이용한 컴퓨터 시뮬레이션을 통하여 검증한다.

• Proceedings of the SAREK Conference
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• 2005.06a
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• pp.100-100
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• 2005

• Proceedings of the PSK Conference
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• 2002.04a
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• pp.89-90
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• 2002

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.94-94
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• 2004