• 한국의학물리학회지:의학물리
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• 제28권3호
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• pp.92-99
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• 2017

In respiratory-induced proton therapy, the accuracy of tracking system and beam controlling is more important than photon therapy. Therefore, a high accuracy motion tracking system that can track internal marker and external surrogate is needed. In this research, our team has installed internal and external marker tracking system at our institution's proton therapy system, and tested the scanning with gating according to the position of marker. The results demonstrate that the developed in-house external/internal marker based gating system can be clinically used for proton therapy system for moving tumor treatment.

• 한국정밀공학회지
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• 제19권8호
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• pp.116-125
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• 2002

Semi-Solid Diecasters usually carry out the Semi-Solid diecasting experiments before producing new casts. At the Semi-Solid diecasting stages, the runner-gate part has been always repeatedly corrected, which leads to a tedious processing time and increased processing cost. A large amount of experience is essential in manual assessment and if the design is defective, much time and a great deal of efforts will be wasted in the modification of the die. In this study, design system has been developed based on design database. In addition, gate experiment for gating system design has been carried out to append the database. It is possible for engineers to make efficient gating system design of Semi-Solid diecasting and it will result in the reduction of expenses and time to be required. The detailed contents of the research are described in the followings.

• 전자공학회논문지
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• 제52권10호
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• pp.56-63
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• 2015

SoC (System-on-Chip) 설계초기 상위수준에서 성능뿐만 아니라 전력 분석이 중요하다. 본 논문에서는 상위수준에서 전력 분석 정확도가 높은 클럭 게이팅 구동 신호 기반 전력 모델을 제안한다. 클럭 게이팅 구동 신호의 조합으로 전력 상태를 정의하며, 클럭 게이팅 구동 신호를 자동으로 추출하여 전력 모델을 자동으로 생성할 수 있다. 실험 결과 평균 96% 이상의 정확도를 보였으며, 상위수준에서의 전력 분석 속도는 게이트 수준 대비 평균 280배 빠른 속도향상을 보였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.324-328
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• 2002

Semi-Solid Diecasters usually carry out the Semi-Solid diecasting experiments before producing new casts. At the Semi-Solid diecasting stages, the runner-gate part has been always repeatedly corrected, which leads to a tedious processing time and increased processing cost. A large amount of experience is essential in manual assessment and if the design is defective, much time and a great deal of efforts will be wasted in the modification of the die. In this study, design system has been developed based on design database. In addition, gate experiment for gating system design has been carried out to append the database. It is possible for engineers to make efficient gating system design of Semi-Solid diecasting and it will result in the reduction of expenses and time to be required. The detailed contents of the research are described in the followings. An attempt is made to link programs incorporating a number of expert design rules with the process variables obtained by commercial FVM softwares, MAGMAsoft, to form a useful package.

• 한국주조공학회지
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• 제20권2호
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• pp.97-103
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• 2000

In this study, a design of experiment, Taguchi method, was applied to optimize gating system design of escalator step die casting parts. Six shape factors which affect filling sequence of melt are adopted and divided into two levels respectively. Initial feeding differences of melt which were calculated by using S/N(signal-to-noise) ratio in each condition were demonstrated with the simulation of Flow-3D software program. Variations of S/N ratio according to shape factors were obtained and the optimal condition of gating system could also be obtained. It could be found that width of gate, contact angle of gate, thickness of runner are more effective factors on the filling sequence of melt than the others in this case of escalator step die casting parts. It showed that the economical gating system and sound filling sequence of melt were obtained by using Taguchi method.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2004년도 제29회 추계학술대회 발표논문집
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• pp.132-135
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• 2004

본 연구는 호흡시에 내부 장기가 움직일 때 시간에 따른 threshold 값을 주어졌을 때 선량분포에 대한 연구를 수행한 것이다. 이전 연구에서 보고 된 것처럼 일정 시간에 따라 움직이는 내부 장기의 움직임은 Rujan 등에 의해 보고된 3차원적 수학적 계산방법에 의해 장기의 위치를 나타내었다. 그 결과 처음exhale에서 1초동안 간의 움직임은 2mm이내에 위치하는 것을 알게 되었다. 그래서 이 연구에서 TGT는 간의 움직임이 가장 적은 처음 exhale에서 1초동안 움직일 때의 선량분포를 평가하였다. TGT 값을 주었을 때 선량분포를 비교하기 위해 다음 조건으로 방사선을 조사하였다. 1) threshold 범위에서 target이 움직일 때(1초, 1.5호), 2) threshold 없이 target이 움직일 때, 3) target이 움직이지 않을때. 각각 조건의 선량분포를 비교 평가하였다

• 한국산업융합학회 논문집
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• 제24권5호
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• pp.597-608
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• 2021

The control head components used in small military vessels are designed to be domestically produced, prototypes, structural analysis, and casting methods are designed and cast. The control head assembly consists of a lever, an aluminum outside cover, Middle, front gear cover, back gear cover, and a zinc worm gear. In order to reverse the design of each component, 3D scanning device was used, 3D modeling was performed by CATIA, and prototype productions were carried out by 3D printer. In order to reduce the cost of components, gating system is used by gravity casting method. The SRG ratio of 1:0.9:0.6 was set by applying non-pressurized gating system to aluminum parts, 1:2.2:2.0 and pressurized gating system to zinc parts, and the shapes of sprue, runner and gate were designed. The results of porosity were also confirmed by casting analysis in order to determine whether the appropriate gating system can be designed. The results showed that all parts started solidification after filling completely. ANSYS was used for structural analysis, and the results confirmed that all five components had a safety factor of 15 more. All castings are free of defects in appearance, and CT results show only very small porosity. ZnDC1 zinc alloy worm gear has a tensile strength of 285 MPa and an elongation of 8%. The tensile strength of the four components of A356 aluminum alloy is about 137-162 MPa and the elongation is 4.8-6.5%.

• 한국산업융합학회 논문집
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• 제24권5호
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• pp.589-596
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• 2021

In this study, the optimum gating system was designed, and the two zinc alloy worm gears were manufactured in single process by applying a symmetrical gating system with 2 runners. The SRG ratio is set to 1 : 0.9 : 0.6, and the cross-sectional shapes such as sprue, runner and gate are designed. In order to determine whether the design of the gating system is appropriate, casting analysis was carried out. It takes 4.380 s to charge the casting 100%, 0.55 to 0.6 m/s at the gates and solidification begins after the casting is fully charged. The amount of air entrapment is 2% in the left gear and 6% in the right gear. Hot spots occurred in the center hole of the gear, and pores were found to occur around the upper part of the hole. Therefore, the design of the casting method is suitable for worm gears. CT analysis showed that all parts of worm gear were distributed with fine pores and some coarse pores were distributed around the central hole of worm gear. The yield strength and tensile strength were 220 MPa, 285 MPa, and the elongation rate was 8%. Vickers hardness is 82 HV.

• International Journal of Control, Automation, and Systems
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• 제2권1호
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• pp.23-38
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• 2004

We proposed the infinity control principle to evaluate the Biological function. The H infinity control was applied to the Sodium (Na) ion selective gating channel on the excitable cellular membrane of the neural system. The channel opening, closing and inactivation processes were expressed by movements of three gates and one inactivation blocking particle in the channel pore. The rate constants of the channel state transition were set to be voltage dependent. The temporal changes in amounts per unit membrane area of the channel states were expressed by means of eight differential equations. The biochemical mimetic used to complete the Na ion selective channel was regarded as noise. The control inputs for ejecting the blocking particle with plugging in the channel pore were set for the active transition from inactivated states to a closed or open state. By applying the H infinity control, we computed temporal changes in the channel states, observers, control inputs and the worst case noises. The present paper will be available for evaluating the noise filtering function of the biological signal transmission system.

• JSTS:Journal of Semiconductor Technology and Science
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• 제8권2호
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• pp.134-138
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• 2008

We present a power gating turn-on mechanism that digitally suppresses ground-bounce noise in ultra-deep submicron technology. Initially, a portion of the sleep transistors are switched on in a pseudo-random manner and then they are all turned on fully when VVDD is above a certain reference voltage. Experimental results from a realistic test circuit designed in 65nm bulk CMOS technology show the potential of our approach.