• Proceedings of the KIEE Conference
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• 2007.11b
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• pp.319-321
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• 2007

사회에서 지대한 관심과 논란의 대상이 되고 있는 한전의 고압전력 설비 중 송전선에서 발생하는 ELF(Extremely Low Frequency)전자계 저감을 위한 사회적비용의 계량화에 관한 연구를 하였다. 송전선로에서 발생되는 극저주파 전자계와 토지가격 사이의 관계론 규명하는 본 연구는 분서의 틀로서 극저주파 전자계 저감을 위한 다양한 기법에 대해서 제시하였다. 또한 다양한 황경가치 평가기법을 비교 분석한 결과, 헤도닉가격법이 가장 적정한 것으로 판단되어 이 분석법을 본 연구의 주된 분석도구로 삼고자 한다. 최근 환경질의 가치평가 기법으로 가장 광범위하게 사용되고 있는 기법중 하나인 헤도닉가격법은 기본적으로 주택, 토시 같은 재화는 그 자체가 가진 물리적 특성뿐만 아니라 외적인 환경 등 다양한 특성으로 이루어진 차별적 재화(differentiated product)라는 헤도닉가설(hedonic hypothesis)을 전제로 한다.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1031_1032
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• 2009

The voltages of unit cells of a fuel cell stack are one of the most significant factors to detect failure conditions and thereof safely control and operate the fuel cell system. In this paper, we describe two methods to monitor the voltages of the unit cells of a stack in consideration of data accuracy, circuit extensibility to various numbers of cells, and cost. The reported methods are approached by (i) the power isolation of cell voltage monitoring part from the communications part and (ii) the utilization of a commercially available cell monitoring integrated circuit IC of a Li-ion battery.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.2
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• pp.540-552
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• 1996

In this paper, a compensation method of disturbance using a disturbance observer is proposed for a force control of a pneumatic robot manipulator. The generated torque by a pneumatic actuator can be estimated based on the pressure signals. The inner torque control system is constructed by feeding back the generated torque to improve the dynamic characteristics of the actuator. In order to reduce the influence of disturbances comprising friction torque, parameter variations of plant and environment and so on, the reaction torque control system is constructed with a disturbance observer which estimates the disturbances based on the reference input to the inner torque control system and the reaction torque sensed with a forced sensor. From some simulations and experiments, it is confirmed that the proposed control system is effective to improve the robustness for the friction torque and the parameter change of object in the force control of a pneumatic robot manupulator.

• Environmental Analysis Health and Toxicology
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• v.9 no.1_2
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• pp.19-23
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• 1994

The tetrazolium dye, 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT), is reduced by live but not dead cell, and this reaction is used as the end point in a rapid drug screening assay. It can also be used for accurate determinations of drug sensitivity but only if a quantative relationship is established between cell number and MTT-formazan production. Several conditions were examined to devise an in vitro assay method in primary cultured hepatocytes, such as optimum wavelength, optimal MTT concentration, optimal incubation time, and cell density.

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2278-2280
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• 2004

이 논문은 이동식 수레형 도립진자 제어에 있어서 비선형적인 특성을 발생시키는 원인중의 하나인 마찰력을 보상하는 방법에 대하여 고찰한다. 여기에 사용된 방법은 모터에 전압을 인가하였을 때의 이동식 수레형 도립진자의 위치와 속도에 대한 데이터를 가지고, 가우시안 반복을 적용한 비선형 최소 자승법을 이용하여 마찰력을 추정하고, 모델링을 하여, 모델링 된 파라미터를 이용하여 비선형적인 특성을 최소화하는 것이다. 이 논문의 주된 결과는 수학적으로 모델링 한 마찰력이 실제의 마찰력과 유사하며, 이 마찰력을 보상함으로서, 이동식 수레형 도립진자의 제어 성능이 향상되었음을 보여준다. 따라서 이 결과는 기존의 마찰력을 무시하고, 이동식 수레형 도립진자를 제어하였을 때보다 마찰력을 보상하였을 때가 더욱 안정된 시스템이 됨을 실험적으로 확인한다.

• Proceedings of the KIEE Conference
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• 1992.07a
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• pp.411-413
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• 1992

This paper proposes a simple and high performance hybrid position/force control of robots based on disturbance compensation by using the disturbance observer in task coordinate space. The disturbance observer linealizes system of robot manipulators in task coordinate space and realizes acceleration control. To realize the strict acceleration control, the disturbance observer whose input is a position signal by simple computation, works as if it were a disturbance detector. The inverse kinematics can be simplified, because the disturbance observer in task coordinate space compensates not only the disturbance but also the error due to the simplification of the inverse kinematics. The new strategy is applied to a three-degrees-of freedom direct drive robot. The robust and simple hybrid position/force control is realized experimentally.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.586-591
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• 2003

The present study addresses experimental results to investigate the effect of the jet supply chamber configuration on the sonic/supersonic swirling jets, as the case study. The experiment is carried out using the convergent nozzle with a various different chamber configurations upstream the nozzle throat, which is composed of four tangential inlet holes for the swirling flows. The jet pressure ratio is varied between 3.0 and 7.0. The sonic/supersonic swirling jet flows are specified by the pitot impact and static pressure measurements and visualized using the Shadowgraph method. The results show that the major structures of the sonic/supersonic swirling jet are strongly influenced by the jet supply chamber.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.869-874
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• 2003

The atomization characteristics were investigated through the influence of the change of GLR and the change of working fluid on droplet size distribution and mean diameter of drop produced by effervescent atomizer. For simultaneous injection of water and high viscous waste vegetable oil, effervescent atomizer with two aerator tubes was specially designed. From the experimental results, regardless of mass fraction of vegetable oil in working fluids, it is expected that effervescent atomizer will exhibit excellent atomization performance at the high GLR conditions.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.04a
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• pp.173-174
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• 2002

2000년 후반을 기준으로 서울시는 인구 1,030만명(남한 전체인구의 25%), 가구 수 350만 가구, 자동차 등록대수는 240만대(남한 전체등록대수의 20%)인 반면, 서울시 전체면적은 605.5 $\textrm{km}^2$으로서 전체 남한 면적의 약 0.6%에 해당하는 거대도시이다 또한 대기오염측면에서 볼 때, 대기오염물질이 확산되기 어려운 분지형태이고, '88-'92년 동안의 대기안정도를 산출한 결과, 약한 안정 및 안정상태가 45% 정도로 대기오염 확산이란 측면에서 매우 불리한 특성을 지니고 있다(어수미 등, 1997) 이러한 토시에서 빈번하게 일어날 수 있는 대기오염현상이 Haze(or smog)이며, 시정장애가 동반된다. (중략)

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.168-171
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• 2002

A neural network model for predicting the quality or soundness of the injected plastic aspherical lens based on process parameters has been developed. The approach uses a Real Time Recurrent Neural Network 4-5-2 (RTRN) trained based on input/output data that were taken from FE analysis worts carried out through a CAE software. The system has been developed to search an optimum set of process parameters and reduce the time required for planning the conditions of plastic injection molding at the design stage.