• 한국전기전자재료학회논문지
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• 제16권5호
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• pp.429-434
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• 2003

The magnetic field sensor was fabricated with superconducting ceramics of BiPbSrCaCuO system. The sensor at liquid nitrogen temperature showed the increase of electrical resistance by applying magnetic field. Actually, the voltage drop across the sensor was changed from zero to a value more than 100 $\mu\textrm{V}$ by the applied magnetic field. The change of electrical resistance depended on magnetic field. The sensitivity of this sensor was 2.9 $\Omega$/T. The sensing limit was about 1.5${\times}$10$\^$-5/ T. The increase of electrical resistance by the magnetic field was ascribed to a modification of the Josephson junctions due to the penetrating magnetic flux into the superconducting material. Considering the observed properties of the superconductor with trapped magnetic flux, a magnetic sensor was fabricated to detect simultaneously both the intensity and the direction of the magnetic field.

• 한국세라믹학회지
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• 제27권4호
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• pp.548-552
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• 1990

Effects of binder addition method during compacting on microstructural change and magnetic characteristics of Sr-ferrite system was investigated. Used binders were PVA and PEG, which were added separately or simultaneously. After compacts were heated at 50$0^{\circ}C$ for 3hr in air for burning out all the binders, they were sintered at 125$0^{\circ}C$ for 2h. Based on results, in the case of using the two binders simultaneously, comparing to single binder system, compacted density was somewhat higher but sintered density was rather lower, and abnormal grain growth was accelerated. According to these sintering characteristics, remanent magnetization and coercive force were also diminished.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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• pp.671-676
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• 2003

This paper presents 3-phase current regulation of SR motor by only single current sensor. The conventional drive system of SR motor has a current sensor per each phase. In this paper, The asymmetric bridge converter which Is able to control independently phases and be excited simultaneously is used fs the driver system for 6/4 poles SR motor. And the sensor Is replaced 3 sensors of each phase with only one on bus line of converter so as to detect current of every phase. A drive logic circuit is designed on EPLD with Delta modulation using a fixed frequency This technique is verified through simulation and experiment.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2016년도 추계학술발표대회
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• pp.829-832
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• 2016

경로 예측 기반의 센서 레지스트리 시스템(Path Prediction-based Sensor Registry System, PP-SRS)는 이기종 환경에서 센서 네트워크 환경에서 센서 데이터의 즉각적인 활용과 끊김 없는 해석을 위해 사용자에게 센서 정보를 제공한다. PP-SRS는 사용자의 위치를 경로 단편으로 사상하여 표현한다. 그리고 경로 단편기반으로 사용자의 경로를 예측한다. 그러나 도로 정보에 대한 경로 단편을 미리 구성해야 사용할 수 있으며 구성된 도로 정보를 무시한 경로가 발생하는 문제점을 가지고있다. 이 논문에서는 이 문제점을 해결하기 위하여 PP-SRS를 위한 격자를 이용한 개선방안을 제안한다. 이 논문은 기존의 경로 단편 표현방법과 제안하는 격자 기반 경로 표현방법에 대하여 비교한 후 PP-SRS에 개선 방법에 대하여 서술한다.

• 한국대기환경학회지
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• 제6권1호
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• pp.57-72
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• 1990

The oxidation of carbon monoxide on a catalyst, $LaSrNiCoO_3$ was investigatigated with a plug flow system. Kinetic quantities such as reaction-rate, reaction order and Arhenius-parameters at various reactor temperature from 200$^\circ$C to 300$^\circ$C were determined. Also, the optimum condition for the oxidation of carbon monoxide with this catalyst was determined and are as follows. Partial pressure of oxigen ; 428mmHg Partial pressure of carbon monoxide ; 332mmHg Mixed moral ratio of oxigen and Carbon monoxide ; 1.3 : 1 Total gas flow ; 224ml/min Reaction temperature ; 340$^\circ$C The reaction kinetic equation at the optimum condition, temperature range from 200$^\circ$C to 340$^\circ$C, are as follow. $$ $v = Ae^{6.5Kcal/RT} [CO]^{0.93 \sim 0.98} [O_2]^{0.42 \sim 0.50}$ $$ In addition to this, numerical calculation were performed to evaluate the mass and heat transfer effect on this system.

• 한국광학회지
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• 제9권4호
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• pp.227-230
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• 1998

가우스 동 결상광학계에서 Strehl ratio(SR)를 구하였다. 광원의 파장이 0.365$\mu\textrm{m}$, 광학계의 조리개수(NA)가 0.5이고 상의 분해 선폭이 0.5$\mu\textrm{m}$일 때 자오면에 비점수차가 있는 가우스 결상광학계와 일정한 진폭의 Rayleigh 동 광학계에서 SR을 이론적으로 구하여 비점수차의 Marechal 한계값을 비교한 결과 각각 0.65$\lambda$와 0.24$\lambda$를 얻었다. Seidel 제1차 수차에 대한 가우스 동과 Rayleigh 동의 Marechal 한계를 구한 결과 가우스 동의 Marechal 한계가 매우 큼을 알 수 있었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1988년도 추계학술대회 논문집
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• pp.98-101
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• 1988

The material system (Bi$\sub$0.7/Pb$\sub$0.3/)Sr$_1$Ca$_1$Cu$\sub$1.8/Ox forms, at 845$^{\circ}C$, two major phases having a high Tc(100K) and a low Tc(∼70K) both of which consists of platelets and a non-superconducting minor phase which has rod-like shape and isolated by the major phases. As the sintering period increases, the amount of high Tc phase increases accompanying the decrease in low Tc phase while the amount of the non-superconducting phase is sintering period independent, resulting in a superconductor with Tc of 100K. Changes in compositions of each phase also occur during sintering due to evaporation of bismuth and lead.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.229-231
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• 2005

A sensorless control scheme for the switched reluctance motor (SRM) drive at speed control is presented in this paper. In this paper proposes a very simple method to estimate the rotor position of a switched reluctance motor. By on-line estimating the self-inductance of the motor, the rotor position of the SR motor is obtained, and a closed-loop drive system can be achieved. Proposed methods can easy implement to application with sensorless SR motor drive system. SR motor simulation executed with self inductance estimation and result represented.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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• pp.852-855
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• 2003

The switched reluctance motor (SRM) is gaining much interest as a candidate for electric vehicle for its simple and rugged construction, ability of extremely high-speed operation. This paper is to design and investigate the capabilities of the SRM for low speed electric vehicle(LSEV)

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2003년도 추계총회 및 연구발표회 초록집
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• pp.179.2-179
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• 2003