• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 추계학술대회
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• pp.735-737
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• 2016

본 논문에서는 SLA 방식의 3D 프린터 사출방식과 사무용 레이저 프린터의 LSU(Laser Scanning Unit)를 융합한 폴리곤 미러 스캐닝 방식의 3D프린터에 대해 핵심이 되는 기능인 기구부 동작에 따른 테스트를 시행하였다. 이러한 테스트는 레이저 동작 및 제어가 가능한지 확인하였으며 아울러 레이저 모듈과 폴리곤 미러를 사용하여 X축에 일정한 점이 출력됨을 확인하였다. 그리고 레이저를 고정된 F-theta 렌즈에 입사한 후 보정된 빔의 출력을 확인하고 보정된 빔을 반사 거울에 맞춰 Z축 상판에 초점이 맞춰지는지를 확인하였다.

• 반도체디스플레이기술학회지
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• 제20권4호
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• pp.171-176
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• 2021

Die-to-wafer (D2W) hybrid bonding in the multilayer semiconductor manufacturing process is one of wafer direct bonding, and various studies are being conducted around the world. A noteworthy point in the current die-to-wafer process is that a lot of voids occur on the bonding surface of the die during bonding. In this study, as a suggested method for removing voids generated during the D2W hybrid bonding process, a flexible mechanism for implementing convex for die bonding to be applied to the bond head is proposed. In addition, modeling of flexible mechanisms, analysis/design/control/evaluation of static/dynamics properties are performed. The proposed system was controlled by capacitive sensor (lion precision, CPL 290), piezo actuator (P-888,91), and dSpace. This flexure mechanism implemented a working range of 200 ㎛, resolution(3σ) of 7.276nm, Inposition(3σ) of 3.503nm, settling time(2%) of 500.133ms by applying a reverse bridge type mechanism and leaf spring guide, and at the same time realized a maximum step difference of 6 ㎛ between die edge and center. The results of this study are applied to the D2W hybrid bonding process and are expected to bring about an effect of increasing semiconductor yield through void removal. In addition, it is expected that it can be utilized as a system that meets the convex variable amount required for each device by adjusting the elongation amount of the piezo actuator coupled to the flexible mechanism in a precise unit.

• The Korean Journal of Physiology and Pharmacology
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• 제7권3호
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• pp.149-155
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• 2003

The aim of the present study was to examine the effects of platycodin D and $D_3$, which are active components derived from the roots of Platycodon grandiflorum A. DC., on the contractile force of the i3olated rat aorta and blood pressure of the anesthetized rat, and also to elucidate its mechanism of action. Both phenylephrine (an adrenergic ${\alpha}1$-receptor agonist) and high potassium (a membranedepolarizing agent) caused great contractile responses in the isolated aortic strips. Platycodin D at high concentration $(24{\mu}g/ml)$ inhibited contractile responses induced by phenylephrine $(10^{-5}\;M)$ and high potassium $(5.6{\times}10^{-2}\;M)$, while low concentrations of platycodin D $(4{\sim}8{\mu}g/ml$) did not affect those responses. However, platycodin $D_3\;(8{\sim}32{\mu}g/ml)$ did not alter the contractile responses evoked by phenylephrine and high $K^+$. Interestingly, the infusion of platycodin $D_3$ (1.0 mg/kg/30 min) significantly reduced the pressor responses induced by intravenous norepinephrine. However, platycodin $D_3$ (1.0 mg/kg/30 min) did not affect them. Taken together, these results show that intravenously administered platycodin D depresses norepinephrine-induced pressor responses in the anesthetized rat, at least partly through the blockade of adrenergic ${\alpha}1$-receptors. Platycodin D also caused vascular relaxation in the isolated aortic strips of the rat via the blockade of adrenergic ${\alpha}1$-receptors, in addition to an unknown direct mechanism. However, platycodin $D_3$ did not affect both norepinephrine-induced pressor responses and the isolated rat aortic contractile responses evoked by phenylephrine and high potassium. Based on these results, there seems to be much difference in the mode of action between platycodin D and platycodin $D_3$.

• 한국세라믹학회지
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• 제15권3호
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• pp.135-139
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• 1978

Sintering oxide which was prepared by sintering at $1200^{\circ}C$ the mixture of ${\gamma}$-$Fe_2O_3$ and $Sb_2O_3$ in 2 : 1 mol ratio, showed 1st electrical switching and stable 2nd switching when D.C. voltage was applied. This electrical switching mechanism was known to be thermal mechanism from dependence of environmental temperature of threshold Voltage(Vm), Current(Im) and the conductivity of the current filament of the sintering oxide.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.1334-1337
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• 2009

The human vision system has visual functions for viewing 3D images with a correct depth. These functions are called accommodation, vergence and binocular stereopsis. Most 3D display system utilizes binocular stereopsis. The authors have developed a monocular 3D vision system with accommodation mechanism, which is useful function for perceiving depth.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.439-440
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• 2006

This research proposes a novel method of shape display to present 3-dimensional objects. Shape displays allow us to feel the actual volume of the object, unlike conventional 2D visual displays of 3D objects. The proposed method employs a wire frame structure to present 3D objects. The wire frame is composed of small units driven by shape memory alloy(SMA) actuators. The drive unit is analogous to the agonist-antagonist system of animal musculoskeletal systems, where the SMA actuators serve as agonist and antagonist muscles. The force in the SMA actuator is controlled by electrical current. The drive unit is equipped with the locking mechanism so that it can sustain the external force exerted by the user as well as the own weight of the wire frame structure. By controlling the current into the SMA actuator and locking mechanism, we call control the angle of the drive unit. A chain of drive units enables presentation of 2 dimensional objects. 3 dimensional presentations are possible by collecting the chains of drive units.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2009년도 춘계학술대회 논문집
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• pp.281-282
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• 2009

• 산업기술연구
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• 제21권A호
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• pp.81-88
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• 2001

In this work, we have developed a 2 degrees of freedom(DOF) motion simulator that can generate the sensation of motion in a 6 DOF space. The motion base has the DOF of roll and pitch, and the purpose of the motion base is to create the sensation of riding a vehicle in a 3D space by controlling the motion base. The dynamics of the mechanism was analysed and the optimal design of the motion base mechanism has been reached. The prototype motion base mechanism was developed and tested. The multi-axis motion controller(MMC) was used to control the two AC servo meters that drive the roll and pitch motion.

• 한국통신학회논문지
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• 제39B권9호
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• pp.614-619
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• 2014

WSN (Wireless Sensor Networks)기반 보안 감시 시스템에서는 센서들이 수집한 이벤트 발생 정보를 전송함에 있어서 이벤트가 발생한 지역의 위치 정보를 함께 제공하는 것이 요구된다. 기존에 많은 연구가 진행되었던 2D기반 위치추적 기법들은 고도가 일정한 환경에서는 꽤 높은 정확도를 보이나, 높이 개념이 추가된 실제 환경에서는 많은 오류를 발생시킬 수 있다. 또한 기존의 3D 위치추적 기법들은 많은 참조노드를 요구하거나, 복잡한 수식 계산을 요구하는 문제점을 가지고 있다. 그러나 본 논문에서 고려하는 실내 보안 감시 시스템에서는 감지된 대상체가 침입자인지 여부를 판단하기 위한 대상체의 높이 예측만을 요구한다. 따라서 본 논문에서는 복잡한 수식 계산이나 많은 참조노드들을 요구하지 않는 대상체 높이예측 기법을 제안한다. 또한 제안 기법의 성능분석을 위하여 여러 가지 시나리오에서 예측 정확도를 측정하였다.

• 대한기계학회논문집
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• 제9권4호
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• pp.528-538
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• 1985

본 논문에서는 crank-rocker 운동에 의해 함수 y=sinx를 만족시키는 3차원 R-S-S-R 함수발생기구를 FDP(Fletcher-Davidon-Powell) 최적화 기법을 응용, 운동학적 으로 무오차점을 고려, 설계하려고 한다. 한편 상기와 같이 최적 설계된 기구의 실 제 운동과 요구된 운동과의 오차분석 및 운동 가능성 여부(mobility check)를 검토하 였으며 FDP 최적화 기법에 필요한 벌칙함수(penalty function)로써 Fiacco-McCormic- krhk Powell의 벌칙함수를 사용하여 그 결과를 비교하였다.