• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.91-91
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• 2004

유압시스템은 1795년 J. Bramah가 물을 작동유체로 사용한 Press를 개발해 사용한 이래 2세기 이상 인간생활의 다양한 분야에 이용되어 왔다. 초기 유압시스템은 쉽게 구할 수 있고, 저장이 용이한 물을 작동유체로 사용하였다. 그러나 물은 부식성, 낮은 점성계수로 인한 저 윤활성과 많은 누설량, 그리고 저온에서의 동결 등과 같은 문제점을 가졌다. 당시에는 물에 대한 부식성이 없는 재료나 물의 누설을 막을 수 있을 만큼의 가공기술이 부족하였으므로 이러한 물의 문제점을 해결하기 위해 1906년 Wiliams와 Janney가 물 대신 기름을 작동유체로 사용하기 시작했다.(중략)

• Journal of KIISE
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• v.44 no.7
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• pp.668-673
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• 2017

Deep neural networks have shown remarkable performance in various fields of pattern recognition such as voice recognition, image recognition and object detection. However, underlying mechanisms of the network have not been fully revealed. In this paper, we focused on empirical analysis of the network parameters. The Faster R-CNN(region-based convolutional neural network) was used as a baseline network of our work and three important parameters were analyzed: the dropout ratio which prevents the overfitting of the neural network, the size of the anchor boxes and the activation function. We also compared the performance of dropout and batch normalization. The network performed favorably when the dropout ratio was 0.3 and the size of the anchor box had not shown notable relation to the performance of the network. The result showed that batch normalization can't entirely substitute the dropout method. The used leaky ReLU(rectified linear unit) with a negative domain slope of 0.02 showed comparably good performance.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.573-576
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• 1995

The realization by many industrial countries that manufacturing is a critical ingredient for attaining economic strength and stability has led to the development of automated systems which were proviously considered as gimmicks. The adaptive skill of the human operator is now being simulated and reproduced by computer that have become more powerful and less expensive. The work presented in this paper forms an investigation of the effects of dynamic viscosity and load of hydraulic oil an pressures with three different circuit(meter-in, meter-out and bleed off). The experimental results showed that pressures increase with an increase in dynamic viscosity and load in bleed off circuit, but there is no variation of pressure in meter-In meter-out circuit.

• The Transactions of the Korea Information Processing Society
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• v.5 no.12
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• pp.3244-3256
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• 1998

집적회로가 고집적화 그리고 고성능화 되어지면서 설계된 레이아웃의 전기적 연결 관계와 회로 성능을 검증할 필요성이 더욱 강조되고 있다. 본 논문에서는 레이아웃으로부터 소자의 기하학적인 모델 파라미터와 기생 저항과 커패시턴스 등을 포함하는 회로 정보를 추출하기 위하여 레이아웃 내의 모든 배선에 대한 도형을 방향성 변을 사용하여 독립된 다각형 블록의 집합으로 기술하고, 이 블록과 소자의 인접여부에 의해 MOS 트랜지스터와 전기적 연결 관계를 찾아서 회로를 추출할 수 있는 새로운 알고리즘을 제안한다.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.446-450
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• 2002

Pneumatic system has been mainly used as main equipment for actuation and control of compressed air force in manufacturing industry, pneumatic circuit for the most part is used in Meter-Out circuit. Meter-Out circuit method is Flow Control Valve to fit in exhaust part of cylinder port. In the reverse, Meter-In circuit is Flow Control Valve to fit in input part of cylinder port. This study examines the dynamic characteristics comparison of Meter-In and Meter-Out Circuits in the pneumatic circuits. The results of the experimental research are obtained to the followings: i ) System Response is Meter-In Circuit more than Meter-Out one before cushion zone. ii) we conjectured that the collision of piston and head cover is ease to collide Meter-In Circuit more than Meter-Out one at the stroke end part.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.12
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• pp.75-84
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• 2001

Due to the high density of integration in current integrated circuit layouts, circuit elements must be designed to minimize the effect of parasitic elements and thereby minimize the factors which can degrade circuit performance. Thus, before making a chip, circuit designers should check whether the extracted netlist is correct, and verify from a simulation whether the circuit performance satisfies the design specifications. In this paper, we propose a new block disassembly technique which can extract the geometric parameters of stacked MOSFETs and the distributed RCs of layout blocks. After applying this to the layout of a folded-cascode CMOS operational amplifier, we verified the connectivity and the effect of the components by simulating the extracted netlist with HSPICE.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.6
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• pp.1343-1348
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• 2011

A modified capacitive detection circuit of charge sharing scheme is proposed, which reduces the static power dissipation and increases the voltage difference between a ridge and valley more than a conventional circuit. The detection circuit is designed and simulated in 3.3V, $0.35{\mu}m$ standard CMOS process, 40MHz condition. The result shows about 47% power dissipation reduction and 90% improvement of difference between a ridge and valley sensing voltage. The proposed circuit is layout without area increasing of a one pixel.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.12
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• pp.234-241
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• 2012

This paper proposes a novel design methodology considering transistor layout variation. The proposed design technique is to improve the transistor's electrical characteristics without performing a circuit simulation to extract transistor layout variation. There are three advantages in the proposed method. Firstly, there is no need to change the normal design flow used in layout designs. Secondly, there is no need to perform simulation in order to extract the transistor layout variation. Thirdly, early warnings in layout design lead to decreasing the number of post layout simulations. Less post layout simulations will decrease the number of iterations in the design cycle and shorten design period. The number of bad transistors in the early design phase were reduced from 17.8% to 2.9% by applying eDRC environment for layout designers to develop Standard Cell Library.