• 대한기계학회논문집A
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• 제24권9호
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• pp.2371-2380
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• 2000

In this paper, we developed the proximity exposure system with the vertical structure of glass and mask stage to minimize the mask's warp caused by the pull of gravity. This system, which canirradiate the ultra violet through 1440 H 850 $\textrm{mm}^2$ and 1330X 1015 $\textrm{mm}^2$ exposure area, has the followingcharacteristics. The glass stage can be inclined by 80 degrees at vertical structure to load substrate withsafety on it. When the glass stage is the vertical state, the gap control, alignment control and exposureof ultra violet are executed. So, it enhances the pattern uniformity by minimizing the mask's warp. Theglass stage can also control the gap between the mask and the substrate by the coarse and fine motioncontrol. The mask stage can adjust the posture of photomask to the position of substrate by imageprecessing method. The galss stage for the gap control and the mask stage for the alignment aredesigned independently for each function.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 춘계학술발표강연 및 논문개요집
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• pp.139-139
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• 2003

기록매체의 고밀도 대용량화를 위하여 자기헤드의 고성능화가 필요하다. 현재 고성능 자기헤드로는 bulk 형 페라이트 헤드, 헤드 갭(Gap)부의 연자성 특성이 우수한 MIG(Metal-in-Gap) 헤드, core부 자성금속을 적층시킨 적층 자기박막헤드 등이 있다. 이들 중 최근 MIG 헤드가 타 자기헤드에 비하여 연자성 특성이 우수하며, 박막의 조직특성에 따라 헤드의 성능이 크게 좌우되는 것으로 보고되고 있어, 이에 따라 특성 및 조직제어에 관한 연구가 진행되고 있다. 고포화 자속밀도의 자기헤드 갭은 자기모멘트가 큰 Fe원소를 기지원소로, 미량의 첨가원소에 기인하는 포화 자속밀도의 조절과 이에 따른 미세구조의 제어에 있는 것으로 연구되고 있다 즉 고포화 자속밀도를 가지는 연자성 박막의 미세구조를 제어함으로서 결정자기이방성이 최소화된 재료에 관한 박막화로 있다.

• 한국자동차공학회논문집
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• 제10권6호
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• pp.227-233
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• 2002

A vehicle longitudinal control strategy with guaranteed string stability for vehicle stop-and-go(SG) cruise control is presented in this paper. The SG cruise control systems should be designed such that string stability can be guaranteed in addition to that every vehicle in a string of SG cruise control vehicles must track any bounded acceleration and velocity profile of its preceding vehicle with a bounded spacing and velocity error. An optimal vehicle following control law based on the information of the 1311owing distance (clearance) and its velocity relative to the vehicle ahead (relative velocity) has been used and string stability analysis has been done based on the control law and constant time gap spacing policy, A validated multi-vehicle simulation package has been shown that the string stability analysis using the approximate model of the vehicle servo-loop which includes vehicle powertrain and brake control system dynamics is valid in the design of the SG cruise control law with guaranteed string stability.

• 제어로봇시스템학회논문지
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• 제12권8호
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• pp.798-804
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• 2006

To overcome the limited relative uncertainty and work range of the existing planar stage and the bulk structure of the contact-less motor for rotation, the novel operating principle to realize the precise rotation is suggested. It uses the two-axial vector forces, normal force and thrust force, of three-induction type of axial motors located $120^{\circ}$ apart, resulting in the contact-free rotation of the mover. Firstly in this paper, the magnetic forces across the air gap are modeled and simulated under the various conditions. It clarifies the feasible range of the derived solution. And the algorithm compensating the strong cross couple between the forces and the control inputs; generally AC magnitude and slip frequency, is given to realize the independent control of six axes. Finally, for the successfully implemented system, the round test and the micro step test results are given.

• 제어로봇시스템학회논문지
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• 제18권3호
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• pp.230-236
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• 2012

Shielding the air-gap magnetic field of the electrodynamic wheel below a conductive plate and opening the shielding plate partially, a thrust force and a normal force generate on the conductive plate at the open area. But, as only the variable controlling both forces is a rotating speed of the electrodynamic wheel, it is very difficult to control the forces independently by the speed. So, we discuss a novel method controlling the forces effectively through manipulating a size of the open area. The independent control is made possible by virtue of the feature that the relative ratio between both forces is irrelevant to an air-gap length and determined uniquely for a specific rotating speed of the wheel. Therefore, the rotating speed and the size of open area become new control variables. The feasibility of the method is verified experimentally. Specially, the controllable magnetic forces are used in a noncontact conveyance of the conductive plate.

• 정보저장시스템학회논문집
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• 제10권1호
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• pp.1-6
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• 2014

Plasmonic lithography is the latest technique to overcome diffraction limit of previous optical lithography. In the plasmonic lithography, the nano gap between nano metal wave guide and photoresist should be in sub-wavelength region. SIL-based plasmonic lithography is the one of the solutions to maintain small air gap. However, the nano gap control is so sensitive that a little disturbance is able to have a large effect on the nano gap control. So, we analyzed the characteristics of disturbance, and then modified the previous controller to suppress the disturbance. We applied two peak filters which were fixed one and adaptively changeable one. We experimentally confirmed the improvement of the nano gap control, which reduced nano gap error by 30 %. The proposed control will improve the quality of lithography pattern.

• 한국지능시스템학회논문지
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• 제19권1호
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• pp.62-68
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• 2009

수정된 PCX(parent-centric recombination) 연산자와 결합한 두 가지 새로운 세대차 모델이 제안된다. 첫째, 자가적응 세대차 모델(SGG, self-adaptation generation gap)은 자손에 의한 부모의 대치 확률을 일정한 수준으로 유지하는 제어 방식이다. 둘째, 가상 클러스터 세대차(VCGG, virtual cluster generation gap)는 클러스터링을 통해 부모간의 거리를 조정해 주며, 이로 인해 개체들이 다양화 될 수 있다. 이 모델에서 부모간의 거리는 클러스터의 크기로 조절된다. 제안된 두 가지 접근법의 효용성을 입증하기 위해서 3 가지 표준적인 문제에 대한 실험이 수행되었다. 가장 최근의 경쟁력 있는 접근법인 CMA-ES와 G3-PCX와 비교한 결과, 제안된 두 기법 모두 기존의 접근법들 보다 우수함을 보여준다.

• 전력전자학회논문지
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• 제22권3호
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• pp.249-255
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• 2017

This paper presents air-gap control according to Y and Delta connections of a double-sided air-gap permanent magnet synchronous motor (DA-PMSM) with independent three-phase structure. In particular, the DA-PMSM used in this study can be applied to low-speed and high-torque applications, such as wind turbines, tidal power generations, and electric propulsion ships, because of its modular stators and a rotor with numerous permanent magnets. Unlike conventional three-phase machines, the DA-PMSM has a symmetrical configuration with double-sided air-gap. Therefore, Y/Delta winding connections and serial/parallel configurations between stator modules are possible. To identify the DA-PMSM operating characteristics, mathematical modeling is analyzed according to the Y/Delta connections. Moreover, air-gap control performances by applying the winding connection methods are verified through experimental results.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집E
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• pp.253-258
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• 2001

Control of drag force on a circular cylinder using a detached splitter plate is numerically studied for laminar flow. A splitter plate with the same length as the cylinder diameter(d) is placed horizontally in the wake region. Its position is described by the gap ratio(G/d), where G represents the gap between the cylinder base point and the leading edge of the plate. The drag varies with the gap ratio; it has the minimum value at a certain gap ratio for each Reynolds number. The drag sharply increases past the optimum gap ratio; this seems to be related to the sudden change in the bubble size in the wake region. This trend is consistent with the experimental observation currently available in case of turbulent flow. It is also found that the net drag coefficient significantly depends on the variation of base suction coefficient.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.323-327
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• 1996

Gap and thickness difference information between blanks are often necessary for tailored blank welding quality evaluation , optimum welding parameters selection and evaluation of shearing machine, blink allocation device accuracy and clamping device. We develope 3D vision system and camera unit using structured lighting for this purpose. A simple ar d efficient scheme for gap and thickness feature recognition Is developed as well as measurements. Experimental results shows this system measuring accuracy is 10 ${\mu}{\textrm}{m}$ and 16${\mu}{\textrm}{m}$ for gap and thickness difference respectively The data are expexed to be useful for preview gap control.