• 비파괴검사학회지
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• 제36권3호
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• pp.202-210
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• 2016

열차폐코팅은 극한의 열환경에서 사용되는 기계요소를 고온으로부터 보호하기 위하여 널리 이용하는 코팅으로, 관련 산업의 경제적 이윤과 사용자 안전에 관련한 중요한 기술이다. 따라서 이런 열차폐코팅의 비파괴적 손상 평가는 그 중요성이 높이 평가되어 왔으나, 코팅 파쇄의 원인이 되는 내부의 미세한 조성 변화를 감지하기 위한 기술적 난제를 안고 있는 연구 주제이다. 본 논문은 열차폐코팅의 비파괴적 손상 평가를 위한 유한요소해석 기반 고감도 와전류 센서 설계 과정을 소개하고, 설계한 센서를 제작하여 진행한 성능 평가를 통해 설계 과정을 검증하였다. 와전류 센서의 성능을 예측하기 위하여 유한요소해석을 수행한 결과, 열차폐코팅의 손상 정도에 따른 센서의 임피던스가 증가와, 마그네틱 쉴드를 적용하였을 때 자속집속에 의한 검출능 향상을 관찰할 수 있었다. 또한 실제 실험결과와 비교를 통해 유한요소해석 결과를 검증하였다.

• Journal of Pharmaceutical Investigation
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• 제31권2호
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• pp.107-112
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• 2001

In order to reduce the systemic side effects and gastrointestinal irritation after its oral adminitration, ketoprofen was formulated as water-soluble packs. The effects of fatty acids and fatty alcohols on the penetration of ketoprofen through excised rat skins were evaluated. The role of stratum corneum as a protective barrier was also investigated. Fatty acids and fatty alcohols were generally effective in promoting ketoprofen penetration. The flux of ketoprofen through rat skin was maximized when oleic acid or lauryl alcohol was used as an enhancer. As the concentration of fatty acids and fatty alcohols varied from 0% to 10%, the amounts of ketoprofen penetrated were in direct proportion to that of fatty acids but those had no relationship with that of fatty alcohols. The penetration of ketoprofen through stripped skin was enhanced compared to normal skin irrespective of enhancer type, which indicated that the action site of enhancers would be stratum corneum.

• 전기학회논문지
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• 제56권3호
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• pp.519-523
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• 2007

In this paper, we propose a precise parameter extraction of interior permanent magnet (IPM) motors based on finite element analysis. For the calculation of the two-axis inductances Ld and Lq, the slotting effect and cross magnetization due to torque angle are considered. It is examined that back electro-motive force (BEMF) constant is affected by the magnetic saturation in different ways dependent on motor types. Numerical analyses and some measurements are performed for a spoke type and a flux barrier type IPM motors

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.867_868
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• 2009

Interior permanent magnet synchronous motor [IPMSM] which has high power density is applied to motor for Hybrid electric vehicle[HEV], Electric vehicle[EV], Fuel cell electric vehicle[FCEV] and electric home appliances. In order to improve efficiency performance of IPMSM, this paper presented a study by making a hole around air barrier. Because concentrated rib stress is distributed by suitable hole, the hole can reduce rib thickness of IPM rotor. And it can help decrease PM[Permanent Magnet] leakage flux. Saliency ratio($L_q/L_d$) is also increased by magnetic circuit change. For this study, structure analysis of rotor is performed by Ansys program.

• 전기학회논문지
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• 제57권10호
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• pp.1777-1781
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• 2008

This paper deals with optimum design criteria for maximum torque density & minimum torque ripple of Synchronous Reluctance Motor (SynRM) according to the rated wattage using response surface methodology (RSM). The RSM has been achieved to use the experimental design method in combination with Finite Element Method and well adapted to make analytical model for a complex problem considering of a number of interaction of design variables. The proposed procedure allows the definition of the rotor shape according to flux barrier number, starting from an existing motor or a preliminary design.

• Journal of Pharmaceutical Investigation
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• 제25권3호spc1호
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• pp.53-59
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• 1995

Ethinylestradiol (EE)-containing matrix was fabricated with ethylene-vinyl acetate(EVA) copolymer to control the release of the drug, Effect of addition of PEG 400 as receptor solution, the stripping of skin and Azone pretreatment on skin on the permeation of EE through the excised mouse skin was also studied. The permeation rate of EE through the excised mouse skin was affected by the PEG 400 volume fraction. The Azone pretreatment on skin didn't affect on the steady state flux, however, the lag time was shortened. The permeation rate of EE through the stripped skin was much larger than that through the whole skin. It showed that the stratum corneum acts as a barrier of skin permeation. The fact that there is little difference in EE permeation between the intact skin and the stripped skin with EVA membrane shows the permeation of EE through the mouse skin is mainly controlled by the membrane.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.814-815
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• 2008

매입형 영구자석 동기전동기의 경우 고효율, 고출력 그리고 넓은 속도 범위와 같은 많은 장점에도 불구하고 상대적으로 큰 코깅토크와 토크 리플로 인하여 정밀한 위치 제어용 전동기로 사용하는데 있어 한계가 있다. 이는 flux barrier와 치 사이의 불연속적인 자기저항의 변화가 주요한 원인 중의 하나로 이를 최소화 할 수 있는 형상 설계가 필요하다. 따라서 본 논문에서는 초기 설계된 매입형 영구자석 동기 전동기의 특성을 향상시키기 위한 형상 설계를 제시하고 실험 결과를 통하여 제안된 설계 방법의 유용성을 증명하고자 한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 A
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• pp.300-302
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• 1997

Synchronous Reluctance Motors(SynRM) with multiple flux barrier structures are considered in this paper. Since the stator of a SynRM is similar as that of an inductin motor, attention is focused here on the rotor structure. We have designed the parameter of SynRM and analyzed the characteristics of the electromagnetic energy conversion.

• Journal of international Conference on Electrical Machines and Systems
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• 제2권2호
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• pp.141-147
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• 2013

Permanent magnet (PM) motors that employ rare-earth magnets containing dysprosium (Dy) are used in electric and hybrid electric vehicles. However, it is desirable to reduce the amount of Dy used since it is expensive. This study investigates the rotor structure of a PM synchronous motor with a Dy-free rare-earth magnet. Flux barrier shapes and PM thicknesses that enhance the irreversible demagnetization are investigated. In addition, a rotor structure that improves the irreversible demagnetization is proposed. We demonstrate that the proposed rotor structure without Dy improves the irreversible demagnetization.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제11B권2호
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• pp.1-8
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• 2001

This paper deals with magnetic field analysis and computation of cogging torque using an analytical method in Interior Permanent Magnet Motor (IPMM). The magnetic field is analyzed by solving space harmonics field analysis due to magnetizing and the cogging torque is analyzed by combining field analysis with relative permeance. In reducing cogging torque, the inferences of various design variable and magnetizing distribution are investigated. It is shown that the slot and pole ratio (the pole-arc / pole-pitch ratio) combination has a significant effect on the cogging torque and presents a optimal flux barrier shape to reduce the cogging torque. The validity of the proposed technique is confirmed with 2-D Finite Element(FE) analysis.