• 천문학회지
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• 제34권4호
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• pp.293-295
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• 2001

A numerical scheme that incorporates a self-consistent cosmic-ray (CR, hereafter) injection model into the combined gas dynamics and CR diffusion-convection code has been developed. The hydro/CR code can follow in a very cos-effective way the evolution of CR modified shocks by adopting subzone shock-tracking and multi-level Adaptive Mesh Refinement techniques. The injection model is based on interactions of the suprathermal particles with self-generated MHD waves in quasi-parallel shocks. The particle injection is followed numerically by filtering the diffusive flux of suprathermal particles across the shock to upstream region according to a velocity-dependent transparency function, which represents the fraction of leaking suprathermal particles. In the strong shock limit of Mach numbers $\ge$20, significant physical processes such as the injection and acceleration seem to become independent of M, while they are sensitively dependent on M for M < 10. Although some particles injected early in the evolution continue to be accelerated to higher energies, the postshock CR pressure reaches a time asymptotic value due to balance between acceleration and diffusion of the CR particles.

• 대한전기학회논문지
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• 제38권10호
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• pp.840-847
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• 1989

It is an important problem that the plasma of high B value is to be confined safely in the research of plasma fusion. So, the Reversed Field Pinch (RFP) plasma has been studied. RFP is stable pinch having self-reversal phenomenon that forms reversed field of itself, but its process of formation is unstable. Therefore, in this paper, we configured the stable RFP by supplying the radio-frequency rotating field just before the RFP is configured by self-reversal phenomenon. Moreover, when conductivity wall is used, toroidal configured by self-reversal phenomenon. Moreover, when conductivity wall is used, toroidal flux is subject to heavy fluctuation in case of high bias field compared with low bias field.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.852-857
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• 2004

In this paper, an angular self-sensing algorithm is proposed and implemented to a Lorentz force type integrated motor-bearing system. It is based on the principle that the flux linkages of stator windings, calculated from the voltage and torque control current, are the functions of the rotor angle. The tracking angular position error is proven to vanish using the Lyapunov stability method, and the experimental results show that the initial error decays within about 5 seconds. It is found that the resolution of the algorithm remains about 1º over the speed range of 100 to 1000 rpm.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 춘계학술대회 논문집
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• pp.333-336
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• 2005

The reduction behavior of $Nb_2O_5$ in aluminum containing self-reducing briquettes(SRNB) was investigated. The time required for slag/metal equilibrium was estimated as about 20 minutes from the addition of SRNB on to the surface of molten steel. The maximum yield of Nb was expected with the slag composition of $60\%CaO-40\%Al_2O_3$. When $CaCO_3$ was used as a flux, the oxidation loss of Al by $CO_2$ should be compensated, and the chemical equivalent ratio of Al to $Nb_2O_5$ of about 1.43 was required to maximize the yield of Nb.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.375-375
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• 2009

For many large-scale applications of high-temperature superconducting materials, large critical current density($J_c$) in high applied magnetic fields are required. A number of methods have been reported to introduce artificial pinning centers(APCs) in $YBa_2Cu_3O_{7-\delta}$(YBCO) films for enhancement of their $J_c$. We report measurements of critical current in $YBa_2Cu_3O_{7-\delta}$ films deposited by PLD on $SrTiO_3$ substrates decorated with Au nanoparticles. Au nanoparticles were synthesized on STO substrates with self assembled monolayer. Microstructural analysis of the obtained YBCO films was performed by using cross-section transmission electron microscopy(TEM). Phase and textural analysis was done using X-ray diffraction. The surface morphology and surface roughness(Ra) of the layers was measured by atomic force microscopy(AFM).

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.607-608
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• 2006

In recent, it became necessary to develop the technology about electrodeless fluorescent lamp according to demand of the electrodeless fluorescent lamp system that used higher efficiency and advantage of long lifetime. Inductively coupled plasma is commonly used for electrodeless lamp due to its ease of plasma generation. An electric power efficiency of electrodeless fluorescent lamp has big relative property of gas in lamp, gas pressure, lamp formation, ingredients of magnetic substance and shape and action frequency etc. We used magnetic substance that open self-examination material of electrodeless fluorescent lamp antenna. Ferrite that is used in this experiment was Mn-Zn type. We have examined temperature and flux characteristic by frequency. Considering using frequency 2.65[MHz], Frequency was changed from 2.05(MHz) to 3.05[MHz] to recognize flux and temperature change of lamp. I used LMS(Lighting Measurement System) to measure flux and IR Camera to measure temperature of lamp.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 D
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• pp.2239-2240
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• 2006

In recent, it became necessary to develop the technology about electrodeless fluorescent lamp according to demand of the electrodeless fluorescent lamp system that used higher efficiency and advantage of long lifetime. Inductively coupled plasma is commonly used for electrodeless lamp due to its ease of plasma generation. An electric power efficiency of electrodeless fluorescent lamp has big relative property of gas in lamp, gas pressure, lamp formation, ingredients of magnetic substance and shape and action frequency etc. We used magnetic substance that open self-examination material of electrodeless fluorescent lamp antenna. Ferrite that is used in this experiment was Mn-Zn type. We have examined temperature and flux characteristic by frequency. Considering using frequency 2.65[MHz], Frequency was changed from 2.05[MHz] to 3.05[MHz] to recognize flux and temperature change of lamp. I used LMS(Lighting Measurement System) to measure flux and IR Camera to measure temperature of lamp.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 하계학술대회 논문집
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• pp.585-586
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• 2010

An induction motor operated with a conventional direct self controller(DSC) shows a sluggish response during startup and under changes of torque command. Fuzzy logic controller(FLC) is used in conjunction with DSC to minimize these problems. A FLC chooses the switching states based on a set of fuzzy variables. Flux position, error in flux magnitude and error in torque are used as fuzzy state variables. Fuzzy rules are determinated by observing the vector diagram of flux and currents. This paper proposes hybrid FLC for direct torque control(DTC) of induction motor drives. This controller is controlled speed using hybrid FLC. The performance of the proposed induction motor drive with hybrid FLC is verified by analysis results at various operation conditions.

• 멤브레인
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• 제23권2호
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• pp.185-188
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• 2013

본 연구는 정밀여과용 관형 분리막 모듈 내에 자체 설계한 기체분사형 노즐을 장착하여 막오염 감소 효과에 따른 투과유속을 측정하였다. 원료 용액으로는 0.1 wt% yeast 입자를 사용하였으며 공기 주입에 따른 막오염 감소 효과를 확인하기 위하여 공기를 주입하지 않은 경우와 주입한 경우의 투과유속을 비교 분석하였다. 공기를 주입하지 않았을 경우 투과유속은 지속적으로 감소하였지만 공기를 주입할 경우 투과유속은 공기를 주입하지 않은 경우와 비교하여 30% 이상 향상됨을 확인하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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• pp.1273-1274
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• 2006

In recent, it became necessary to develop the technology about electrodeless fluorescent lamp according to demand of the electrodeless fluorescent lamp system that used higher efficiency and advantage of long lifetime. Inductively coupled plasma is commonly used for electrodeless lamp due to its ease of plasma generation. An electric power efficiency of electrodeless fluorescent lamp has big relative property of gas in lamp, gas pressure, lamp formation, ingredients of magnetic substance and shape and action frequency etc. We used magnetic substance that open self-examination material of electrodeless fluorescent lamp antenna. Ferrite that is used in this experiment was Mn-Zn type. We have examined temperature and flux characteristic by frequency. Considering using frequency 2.65[MHz], Frequency was changed from 2.05[MHz] to 3.05[MHz] to recognize flux and temperature change of lamp. I used LMS(Lighting Measurement System) to measure flux and IR Camera to measure temperature of lamp.