• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.3
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• pp.86-91
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• 2020

An important factor of rough road modeling is analyzing the shear behavior properties of the rough road. These properties influence the drawbar pull of the tool when interacting with the soil used in agriculture. Furthermore, shear behavior properties are important because sinkage and shear stress are generated when wheels drive on rough roads. In this study, we performed a direct shear test to investigate the shear behavior properties of soils and compare with the direct shear simulation; shear force derived by the coupled analysis of discrete element method; and multi-body dynamics. Soil contact parameters were measured in a wheel and soil contact simulation followed by comparison of the simulated and experimentally measured shear force.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.821-822
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• 2013

• 전기의세계
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• v.39 no.9
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• pp.39-45
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• 1990

전자 액츄에이터의 일종인 LPM(linear pulse motor)은 직선왕복 운동을 필요로 하는 모든 응용기기의 구동에 적합한 선형 전동기로서 직접구동(direct drive)방식을 채택함으로써 회전형 전동기를 사용하는것과는 달리 감속장치, 동력전달 기구가 불필요하여 전체시스템의 구성에서 부품의 수를 줄일 수 있기 때문에 제품의 신뢰성이 향상되고 소형경량화 할 수 있다. 또한 LPM은 기계적 구조가 간단하고 비접속 직접구동이 가능하므로 기기의 특성 변화가 적고 보수성이 우수한 성능을 가지고 있다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.109-110
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• 2011

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.96.1-96.1
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• 2008

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.237.2-237.2
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• 2010

Although oscillating water column type wave energy devices are nearing the stage of commercial exploitation, there is still much to be learnt about many facets of their hydrodynamic performance. The techniques of Computational Fluid Dynamics (CFD) are applied to simulate a wave energy conversion device in free surface such as waves. This research uses the commercially available ANSYS CFX computational fluid dynamics flow solver to model a complete oscillating water column system with savonius turbine incorporated at the rear bottom of the OWC chamber in a three dimensional numerical wave tank. The purpose of the present study is to investigate the effect of an average wave condition on the performance and internal flow of a newly developed direct drive turbine (DDT) model for wave energy conversion numerically. The effects of blade angle and front lip shape on the hydrodynamic efficiency are investigated. The results indicated that the developed models are suitable to analyze the water flow characteristics both in the chamber and in the turbine. For the turbine, the numerical results of torque were compared for the all cases. The results of the testing have also illustrated that simple changes to the front wall aperture shape can provide marked improvements in the efficiency of energy capture for OWC type devices.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.7
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• pp.56-65
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• 1997

In this paper, we propose a reference input odification-type iterative learning control law for a class of discrete-time nonlinear systems and prove the convergence of the output error. We can get the high-precision in case of the trajectroy control when the proposed control law is properly combined with a feedback controller, and we can easily implement the learning control law compared to the control input modification-type learning control law. To show the validity and the convergence perfodrmance of the proposed control law, we perform experimentations on the trajectroy control and rejection of periodic disturbance for a 2-axis SCARA-type direct drive robot.

• Journal of the Korean Home Economics Association
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• v.42 no.2
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• pp.83-98
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• 2004

The purpose of this study was to investigate the effects of body image, body dissatisfaction, and drive for slimness, as mediated by self-esteem and depression, on eating disorder behavior according to gender The subjects of this study were 243 male and 323 female university students from Chungbuk National university in Cheonju. On the basis of previous literature, the theoretical model was specified and estimated for the adequacy of statistical fit for male and female students separately. The proposed theoretical model was supported by the data and fitted adequately. As expected, body image, body dissatisfaction, and desire for thinness had a direct effect on self-esteem for female students. However, whereas body image and body dissatisfaction directly influenced on male students' self-esteem, while desire for gaining weight had no direct effect. Eating disorder behavior in female students was predicted by body dissatisfaction, body image, and self-esteem. For male students, desire for gaining weight and self-esteem strongly predicted eating disorder behavior. The results indicate that the influence of body image, body dissatisfaction, and desire for thinness on eating disorder behavior can be mediated not by depression but by self-esteem.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.76-79
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• 2005

포항풍력에너지연구소와 (주)보국전기는 에너지 관리공단의 지원으로 2002년부터 직접구동형 풍력터빈( KBP-750D) 에 사용될 발전기 개발을 시작하여 2005년 3월 개발을 완료하였다. KBP-750D에 사용되는 발전기는 증속을 위한 gearbox를 사용하지 않는 직접 구동형이고, 영구자석을 사용하여 여자하는 형식이다. 이런 특징은 풍력발전에서 요구하는 주요 요구조건인 고 효율, 고 신뢰성을 만족시키기 위해서 매우 중요하다. 개발된 발전기는 25 rpm 에서 800 kW의 정격을 가지도록 설계되었다. 공극 직경은 3,320mm 이며, stator의 길이는 705mm, 공극은 4.5mm 이고, 극수는 84이다. 또한 전체 중량은 약 22 ton이다. 이 논문에서는 발전기의 물리설계, 공학설계, 제작 및 시험결과에 관해서 기술한다.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.630-631
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• 2009

Recent developments such as concern over global warming, depletion of fossil fuels and increase in energy demands by the increasing world population has eventually lead to mass production of electricity using renewable sources. Apart from wind and solar, ocean holds tremendous amount of untapped energy in forms such as geothermal vents, tides and waves. The current study looks at generating power using waves and the focus is on the primary energy conversion (first stage conversion) of incoming waves for two different models. Observation of flow characteristics, pressure and the velocity in the augmentation channel as well as the front guide nozzle are presented in the paper. A numerical wave tank was utilized to generate waves of desired properties and later the turbine section was integrated. The augmentation channel consisted of a front nozzle, rear nozzle and an internal fluid region representing the turbine housing. The analysis was performed using the commercial CFD code.