• Elastomers and Composites
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• v.2 no.1
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• pp.31-36
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• 1967

As a series of the studies of thin rubber coated fabrics, the experiments were concentrated on the investigation of the physical properties of the surface and back coated fabrics with natural and synthetic rubber. Cotton poplin and nine other cotton shootings were used as a base fabric and both sides of fabric, face and back, were coated by means of topping or spreading process. The physical properties of finished material were broadly investigated especially in view of the quality requirements of the poncho.

• Elastomers and Composites
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• v.4 no.1
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• pp.83-88
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• 1969

As a part of a series of previous studies, physical properties of various portions of a tire made of NR-Syn. R bloods were studied. 1. It was found, in general, most effective for tire tread when 50 parts of HAF black was blended with NR and Syn. R with a ratio of 70/30. 2. It was found that the use of SBR 1712 has an advantage in price, easy processing and physical properties than other synthetic rubber. 3. A technical compounding of various portions of a tire has to be determined for optimum cure conditions.

• Elastomers and Composites
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• v.4 no.1
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• pp.89-93
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• 1969

1. Physical properties of various nylon cords in a tire, both of home and foreign products are studied. The experimental data for home nylon cords appeared to be quite satisfactory for use in a tire compared with foreign nylon cords with respect to its tenacity, elongation, shrinkage and contraction. 2. Excellent results have been obtained with 50 phr carbon in butyl-carbon compounding.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.253-255
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• 2003

디지털 및 정보통신 기술의 급속한 발전은 전력계통 안정화를 위한 전력계통 운영의 제반 환경에 혁명적인 변화를 예고하고 있다. 이미 선진국에서는 이러한 디지털 및 정보통신 기술에 기반하여 IED 및 변전 시스템을 개발 설치 운영하고 있다. 본 논문에서는 우리나라의 현재 전력자동화시스템 및 변전시스템을 살펴보고, 차세대 전력자동화시스템을 구축하기 위해 필요한 SCC 운영시스템, 변전시스템, IED의 개발 및 구축 방향에 대해 고찰한다.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2000.10a
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• pp.90-100
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• 2000

The present paper investigates the elasto-plastic buckling of ball-jointed single layer latticed domes considering the connection characteristics. The domes are composed of tubular member elements, ball joints and connectors. To judge yielding of the member, the ends and central part of tubular member elements are assumed as five elasto-plastic springs. Elasto-plastic buckling load can be identified the yielding load of estimated member As a numerical analysis technique, loading incremental method based on the Newton-Raphson method is used. The effects of connection characteristics are investigated by the following points; (1) the length of rigid zone, (2) looseness of screw, (3) diameter of connector Finally, it is emphasized that the connection characteristics as well as the material non-linearity have significant effects upon the buckling toad of domes.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.10
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• pp.130-140
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• 2003

This paper presents an $H_\infty$controller synthesis based on disturbance observer for the trajectory control of a hydraulic excavator. Compared to conventional robot manipulators driven by electrical motors, hydraulic excavator have more nonlinear and coupled dynamics. In particular, the interactions between an excavation tool and the materials being excavated are unstructured and complex. In addition, its operating modes depend on working conditions, which make it difficult to not only derive the exact mathematical model but also design a controller systematically. In this study, the approximated linear model obtained through off-line system identification is used as nominal plant model for a disturbance observer. A disturbance observer based tracking controller which considers the effect of disturbance and model uncertainty is synthesized in $H_\infty$frameworks. Simulation results are used to demonstrate the applicability of the proposed control scheme.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.745-748
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• 2006

This study investigates the fundamental properties and examines spalling appearances and residual compressive strength of high strength concrete containing hybrid organic fibers subjected to fire. Test showed that overall, an increase of fiber content decreased the fluidity of concrete, but specimens containing polyvinyl alcoho(PVA)+polypropylene(PP) fiber and nylon(NY)+PP fiber had improved flow. In addition, the air content of all specimens was properly ranged in target value, regardless of fiber content. As for the spalling properties when completed the fire test, control concrete exhibited spalling occurrence due to sudden elevated temperature. However, specimens containing more than 0.1 vol% of PP fiber prevented the spalling, while specimens containing PP+CL and PVA+PP fiber can protected from fire in more than 0.15vol% of the fiber content. Importantly, a specimen containing only 0.05vol% of NY+PP showed the favorable spalling resistance performance.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.11a
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• pp.81-84
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• 2006

특징점 추출 기반의 지문인식 알고리즘에서 방향정보는 이진화 과정 및 지문 분류, 인증에 쓰이므로 매우 중요하다. 모델기반의 방향정보를 추정하는 방법은 영상 전체에 있는 노이즈에 대하여 매우 강건하지만, 상처와 같이 국부적으로 존재하는 노이즈 정보의 추출에는 취약하다. Sobel Operator의 경우에는 국부적인 노이즈 요소에는 민감한 특정을 보인다. 따라서 본 논문에서는 모델링된 방향정보와 Sobel Operator 의 방향 정보를 백터에 의한 상호 결합하여 영상의 방향 정보를 개선하고 노이즈 블록을 추정하는 방법을 제안한다.

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.156-158
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• 1993

This paper presents several techniques of power spectrum estimation for high impedance fault detection. High impedance faults are those faults with current too low to be reliably cleared by conventional overcurrent protection. So power spectrum estimation is required. AR and MA techniques require optimal order for good performance of power spectrum estimation because these techniques are unstable for order selection. ARMA and Extended techniches are stable for order selection and have very sharp response. So ARMA and Extended Prony techniques are suitable for our purpose.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.180-183
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• 2010

본 연구에서는 개선된 영역기반의 패턴매칭 기법을 사용하여 이동물체의 탐색과 검출을 수행하였다. 시간에 따라 변화하는 이동물체의 안정된 추적을 위해 매 영상 프레임마다 이동물체의 윤곽선을 탐지하여 다음 영상에서의 템플릿으로 사용하기 위해 갱신하였으며, 패턴매칭의 연산속도 향상을 위해 패턴 정합률에 따라 영상을 다른 비율로 압축하여 추적하는 방법을 제안하였다. 기존의 영상파일을 사용하여 시뮬레이션 한 결과 이동물체의 검출과 추적에 양호한 동작을 보여주었으며 제안된 방법의 실시간 동작 가능성을 조사하였다.