• The Korean Publising Journal, Monthly
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• s.338
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• pp.18-21
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• 2004

• Electrical & Electronic Materials
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• v.26 no.10
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• pp.10-16
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• 2013

• Electrical & Electronic Materials
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• v.30 no.5
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• pp.3-8
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• 2017

• Proceedings of the Korean Fiber Society Conference
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• 1997.10a
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• pp.234-237
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• 1997

• Electrical & Electronic Materials
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• v.28 no.6
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• pp.10-19
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• 2015

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.09a
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• pp.41-48
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• 2005

• The Korean Journal of Rheology
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• v.2 no.2
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• pp.19-27
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• 1990

레이저와 타이머장치를 설치한 낙구식 점도계에서 구와 니들이 주어진 구간을 통과 하는 시간을 측정하여 종말속도를 정확히 결정하였고 점성이 작은유체와 낮은 전단률 점성 과 영전단률 점성은 속이 빈 알루미늄 구와 니들이 이용하여 측정하였다. 알루미늄 구와 니 들의 속에 철분을 삽입하여 밀도를 다양하게 변화시켰다. 낙구식 점도계에서 측정한 낮은 전단률 점성과 영 전단률 점성 그리고 모세관점도계에서 측정한 높은전단률 점성과 무한 전 단률 점성을 이용하여 점탄성 유체의 특성이완시간을 결정하였다. 실린더 속의 시험용 유체 를 교란시키지 않고 밑면에 떨어진 구를 회수하는 장치를 설치하였다. 이 장치는 하나의 구 로써 점탄성유체의 특성확산시간을 측정하는데 대단히 효과적이었다. Polyacrylamide Separan AP-273 용액(농도 500-200 wppm)의 특성이안시간과 특성화산시간을 낙구식 점도 계와 모세관 점도계의 실험결과를 이용하여 결정하고 폴리며 용액의 퇴화 현상을 실험적으 로 분석하였다.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.05a
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• pp.184-187
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• 2002

Compression molding was specifically developed for replacement of metal components with composites. As the mechanical properties of the products are dependent on the separation and orientation, it is important to research the fiber mat structure and molding conditions. In this study, the effects of the fiber mat structure(NP: 5, 10, 25punches/$\textrm{cm}^2$) and the mold closure speed($\dot{\textrm{h}}$=0.1, 1, 10mm/min) on the viscosity of composites were discussed. The composites is treated as a Non-Newtonian power-law fluid. The parallel-plate plastometer is used and the viscosity is obtained from the relationship between the compression load and the thickness of the specimen.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.1
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• pp.59-66
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• 2002

This paper presents the process of the needle lift estimation ova common-rail injector fur HSDI(High Speed Direct Injection) diesel engines. A nonlinear mathematical model of dynamic behaviors of common-rail injector is established at first. Based on the mathematical model of the common-rail injector, the methodology of estimating the injector needle lift is introduced. A sliding mode observer is applied to overcome the model uncertainties. The common-rail injector model and the needle lift estimator are verified by simulations and experiments. The simulation and experimental results indicate that the model outputs are in a good agreement with experimental data, and the proposed nonlinear sliding observer can effectively estimate the needle lift.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.11a
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• pp.174-177
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• 2007

In this work, we researched static and dynamic characteristics concern to hydraulic regulator control process and parameter setting, which is used on liquid rocket engine regulation. The hydraulic regulator of 8K14 "SCUD" 9D21 engine is analyzed and on the basis of the developed mathematical modeling the analysis of response time and certification on automatic control accuracy is carried out. In this process, we find out specific design configuration of needle valve flow section that effects on pressure regulation performance.