• 대한기계학회논문집A
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• 제35권1호
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• pp.85-90
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• 2011

철도차량에서 활주방지제어장치를 포함한 제동 시스템을 이해하는 것은 안전과 철도차량의 운영을 위하여 매우 중요한 요소이다. 본 논문에서는 실제 철도차량에 장착되어 있는 활주방지제어장치와 동역학 모델이 포함되어 있는 HILS 시스템을 이용하여 한빛 200 의 활주현상을 해석하였다. 활주를 발생시키기 위해 Simulink 를 이용하여 프로그램 하였고,결과를 확인하기 위한 GUI 프로그램은 dSPACE 사에서 제공하는 ControlDesk 를 이용하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.519-524
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• 2004

This study is concerned with the braking distance estimation using frictional energy rate. First, steady state rolling analysis is performed, and using this result, the braking distance is estimated. Dynamic rolling analysis during entire braking time period is impratical, so that this study divides the vehicle velocity by 10km/h to reduce the analysis time. The multiplication of the slip rate and the shear stress provides the frictional energy rate. Using frictional energy rate, total braking distance is estimated, In addition, ABS(Anti-lock Brake System) is considered, and two type of slip ratios are compared, One is 15% slip ratio for the ABS condition, and the other is 100% slip ratio which leads lo the almost same braking distance as the elementary kinematic theory. A slip ratio is controlled by angular velocity in ABAQUS/Explicit, A 15% slip ratio gives the real vehicle's braking distance when the frictional energy occurred al disk pad is included. Disk pad's frictional energy rate is calculated by the theoretical approach.

• IMMUNE NETWORK
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• 제4권3호
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• pp.176-183
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• 2004

Background: Human seminal plasma (HSP)-induced hypersensitivity is one of the serious complications with sexual intercourse. The clinical manifestations of HSP-induced hypersensitivity may be related to the release of vasoactive mediators from mast cell induced by HSP. It has recently been reported that HSP modulates immune systems and induces mast cell degranulation and histamine release from rat peritoneal mast cells (RPMC). Ketotifen and disodium cromoglycate (DSCG), anti-asthmatic and anti-allergic drugs, have a role of mast cell stabilization and inhibit mast cell-induced leukocyte rolling and adhesion. But the inhibitory agents of HSP-induced mast cell activation are unknown. This study was performed to investigate the effects of DSCG and ketotifen on the HSP-induced mast cell activation. Methods: For this, influences of DSCG and ketotifen on the human seminal plasma-induced degranulation, histamine release and morphological changes of RPMC were observed. Results: The mast cell degranulation and histamine release of RPMC by HSP were induced in a dose-dependent fashion. The HSP-induced cytomorphological changes such as swelling, intracellular vacoules, and interrupted cell boundary were significantly inhibited by pretreatment with DSCG or ketotifen. DSCG and Ketotifen inhibited the HSP-induced degranulation and histamine release from RPMC. Conclusion: From the above results, it is suggested that DSCG and ketotifen have a inhibitory effect of the HSP-induced mast cell activation. DSCG and ketotifen may be used for treatment of HSP-induced hypersensitivity.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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• pp.536-539
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• 2003

In electric motor coaches, the rolling stocks move by the adhesive effort between rail and driving wheel. Generally, the adhesive effort is defined by the function of both the weight of electric motor coach and the adhesive effort between rails and driving wheel. The characteristics of adhesive effort is strongly affected by the conditions between rails and driving wheel. When the adhesive effort decreases suddenly, the electric motor coach has slip phenomena. This paper proposes a re-adhesion control algorithm which uses the maximum adhesive effort by instantaneous estimation of adhesion force using load torque disturbance observer. Based on this estimated adhesive effort, the re-adhesion control is performed to obtain the maximum transfer of the tractive effort.

• 한국정밀공학회지
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• 제26권10호
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• pp.47-55
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• 2009

In this study, a robot foot having toes for firm stepping on uneven surface is proposed. The toes are connected to the lower leg by parallel links so that the lower leg can rotate in the rolling and pitching directions during stance phase without ankle joint. The landing performance of the foot on uneven surface was evaluated by relative comparison with that of the most common foot making point contact with the walking surface, since the test conditions considering real uneven surface could be hardly defined for its objective evaluation. Anti-slip margin(ASM) was defined in this study to express the slip resistance of a robot foot when it lands on a projection with half circular-, triangular- or rectangular cross section, assuming that uneven surface consists of projections having these kind of cross sections in different sizes. Based on the ASM analysis, the slip conditions for the two feet were experimentally confirmed. The results showed that the slip resistance of the new foot is not only higher than that of the conventional point contact type foot but also less sensitive to the surface friction coefficient.

• 전력전자학회논문지
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• 제9권6호
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• pp.635-642
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• 2004

본 논문에서는 최대 견인력 제어를 위해서 부하토크외란관측기와 속도센서리스 백터제어를 이용하여 점착력 계수를 추정하고 추정한 점착력 계수의 미분치를 PI 토크 제어하는 Anti-slip제어를 제안한다. 점착력 계수를 추정하기 위해서는 전압, 전류값 뿐만 아니라 자속이나 속도정보가 필요하다. 따라서 전동기의 회전속도를 정확하게 검출 할 수 있는 속도센서가 필요하게 된다. 그러나 속도검출을 위해 속도센서를 부착하는 것은 여러 가지 면에서 단점을 가지고 있다. 이러한 문제점을 해결하기 위하여 속도센서 없는 센서리스 구동방식에 의한 부하토크외란관측기를 설계하여, 점착력 계수를 추정한다. 이와같은 제어 알고리즘을 구현하기 위하여 1C1M 철도모의장치를 이용하여 제안된 알고리즘을 실험을 통하여 확인하였다.

• 전력전자학회논문지
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• 제8권4호
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• pp.366-374
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• 2003

본 논문에서는 최대 견인력 제어를 위해서 부하 토크 외란 관측기를 이용하여 점착력 계수를 추정하고 추정한 점착력 계수의 미분치를 PI 토크 제어하는 Anti-slip 제어를 제안한다. 부하 토크 외란 관측기는 회전자의 위치 정보와 토크 전류의 정보를 이용하여 부하 외란 토크를 추정하고, 부하 외란 토크에 철도차량 상수를 미용하여 점착력 계수를 추정한다. 또한 부하토크외란 관측기는 구조가 간단하며, 시스템의 외란 및 각종 제어이득. 시스템의 상수 변화에 대해서도 견실한 견인력 제어 특성을 가지고 있다. 이와 같은 제어 알고리즘을 구현하기 위하여 IC4M(1-Controller 4-Motor) 축소형 철도차량시스템을 이용하여 제안된 알고리즘을 시뮬레이션과 실험을 통하여 확인하였다. 또한 실제 철도차량시스템의 경우 선로 표면의 상태 변화 및 차량속도의 가감에 따른 공전속도에 대한 점착력의 관계를 축소형 철도차량시스템으로 구현하여, 실제 철도차랑시스템의 경우와 비교 분석하여 최대 견인력제어가 되도록 하였다.

• 한국산학기술학회논문지
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• 제7권6호
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• pp.1064-1071
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• 2006

본 논문에서는 최대 견인력 제어를 위해서 부하토크외란관측기와 속도센서리스 벡터제어를 이용하여 점착력 계수를 추정하고 추정한 점착력 계수의 미분치를 PI 토크 제어하는 Anti-slip제어를 제안한다. 점착력 계수를 추정하기 위해서는 전압, 전류값 뿐만 아니라 자속이나 속도정보가 필요하다. 따라서 전동기의 회전속도를 정확하게 검출할 수 있는 속도센서가 필요하게 된다. 그러나 속도검출을 위해 속도센서를 부착하는 것은 여러 가지 면에서 단점을 가지고 있다. 이러한 문제점을 해결하기 위하여 속도센서 없는 센서리스 구동방식에 의한 부하토크외란관측기를 설계하여, 점착력 계수를 추정한다. 이와 같은 제어 알고리즘을 구현하기 위하여 1C1M 철도모의장치를 이용하여 제안된 알고리즘을 실험을 통하여 확인하였다.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.30-35
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• 2004

Several roll motion reduction devices are reviewed and suggested for the application in FPSO. The firstly suggested solution is the shape of the bilge. The next is a bilge keel. The last suggestion is the ART (anti-rolling tank). Typical U-tube type ART is designed for a FPSO and examined extensively by model experiment. The model section was made of transparent acryl. Free decay test, forced oscillation test and wave test were carried out at a two-dimensional wave flume. U-tube type ART is effective only when the natural periods of ART and ship are same. Therefore, the divided U-tube type ART with split plate is suggested for the reduction of the roll motion of a FPSO over the wide range of the roll period.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1388-1398
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• 2011

Air pollution in subway tunnel is primarily caused from the wear of metallic materials. As undesirable substance, PM(Particulate Matter) can especially harm the health of passengers and workers as well as clog the main parts of rolling stock such as inverters. To improve the air quality in subway tunnel, SMRT(Seoul Metropolitan Rapid Transit Corporation) has developed anti-pollution devices such as Magnetic Dust Collector, Vacuum Cleaner For Rail Road and Particulate Removing Sprinkler Vehicle. Introducing these mechanical devices, this paper is mainly devoted to explaining the characteristics of collected dust according to the result of particle-size analysis and componential analysis.