• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.260-264
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• 1996

In this study, the dieiectric breakdown of epoxy composites used for transformers was experimented and then its data were simulated by Weibull distribution probability . As a result. first of all, speaking of dielectric breakdown properties, the more hardener increased the stronger breakdown strength at low temperature, and the breakdown strength of specimens because it is believed that the adding filler farms interface and charge is accumulated in it, therefore the molecular motility is raised, the electric field is concentrated, and the acceleration of electron and the growth of electron avalanche are early accomplished. In the case of filled specimens with treating silane, the breakdown strength become much higher since the suggests that silane coupling agent improves interfacial combination and relays electric field concentration. Finally, from the analysis 7f weibull distribution. it was confirmed that as the allowed breakdown probability was given by 0.11[%].

• Journal of Plant Biology
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• v.38 no.1
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• pp.33-38
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• 1995

Hydroxyurea (HU), a DNA synthesis inhibitor, was tested as synchronizing agent in root-tip meristem of Allium wakegi. Roots were treated with 2.5mM HU for 14 h to accumulate meristem root-tip cells at the G1/S interface. After release from HU block, the cells re-entered the cell cycle with a high degree of synchrony. Synchronized mitotic frequency of A. wakegi was 22.7%, which was about 3.9 times as high as that of the control. The highest metaphase index(23.0%) was obtained when, 6 h after release from the HU block, the roots were treated with 0.05% colchicine for 2 h. Modifying various Giemsa staining protocols defined for animals and a few plant species, G-bands were visualized at prometaphase and metaphase chromosomes of A. wakegi. The higher degree of chromosome condensation, the less differential bands could be resolved. This is the first demonstration introduced partial mitotic synchronization into G-banding in plant.

• Macromolecular Research
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• v.10 no.1
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• pp.24-33
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• 2002

Interfacial and microfailure properties of carbon fiber/epoxy composites were evaluated using both tensile fragmentation and compressive Broutman tests. A monomeric and two polymeric coupling agents were applied via the electrodeposition (ED) and the dipping applications. A monomeric and a polymeric coupling agent showed significant and comparable improvements in interfacial shear strength (IFSS) compared to the untreated case under both tensile and compressive tests. Typical microfailure modes including cone-shaped fiber break, matrix cracking, and partial interlayer failure were observed under tension, whereas the diagonal slipped failure at both ends of the fractured fiber appeared under compression. Adsorption and shear displacement mechanisms at the interface were described in terms of electrical attraction and primary and secondary bonding forces.

• Journal of The Korean Association of Information Education
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• v.1 no.2
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• pp.45-56
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• 1997

A design of Advisory Tutoring Agent(ATA) is proposed to help a student on the basis of a student-oriented discovery learning, The agents adaptively build a student model and interact with a student as well as each other to give a piece of advice at a proper time. The appropriateness of advice depends on the agents' reasoning sod interaction performed based on the student model. domain knowledge, teaching strategy, and user-friendly interface. The design has been applied to a simple English learning environment.

• 한국정보교육학회:학술대회논문집
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• 2008.01a
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• pp.275-280
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• 2008

교수 학습용 디지털 콘텐츠에서 상호작용은 매우 중요하며 이와 관련된 다양한 연구가 진행되고 있다. 그러나 이러한 상호작용을 제공하기 위해서는 하위단계의 프로그래밍 및 시스템 설계를 위한 시간적 경제적 비용이 반드시 요구된다. 본 연구에서는 사용자에게 프로그래밍이 요구되지 않는 친숙한 'Pencil & Paper' 방식의 인터페이스를 제안한다. 제안 인터페이스에서는 디지털 잉크 인터페이스를 기반으로 교수자가 프레젠테이션 하기 위한 상호작용을 분석한다. 또한 교수자를 대신할 가상 프레젠터의 애니메이션 효과를 적용하여 교수자와 학습자간의 활발한 상호작용을 제공한다. 본 연구의 결과는 온라인 교육이나 전자 책, 지능형 교육 시스템 등 상호작용이 가능한 교육용 컨텐츠 개발에 확대 적용될 수 있을 것으로 기대한다.

• JSTS:Journal of Semiconductor Technology and Science
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• v.5 no.4
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• pp.243-248
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• 2005

The UAV (Unmanned Aerial Vehicle) systems like unmanned autonomous helicopters are used in various missions of flight navigation and used to collect the environmental information of the surroundings. To realize the full functionalities of the UAV, the software part becomes a challenging problem. In this paper embedded real-time software architecture for unmanned autonomous helicopter is proposed that guarantee real-time performance of hard-real time tasks and re-configurability of soft-real time and non-real time tasks. The proposed software architecture has four layers: hardware, execution, service agent and remote user interface layer according to the reactiveness level for external events. In addition, the layered separation of concurrent tasks makes different kinds of mission reconfiguration possible in the system. An Unmanned autonomous helicopter system was implemented (Kyosho RC Helicopter) in our lab to test and evaluate the performance of the proposed system.

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.1
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• pp.127-132
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• 2008

This study proposes a Natural Language Query Framework (NLQF) for the semantic web. It supports an intelligent inference at a semantic level. Most of previous researches focused on the knowledge representation on the semantic web. However, to revitalize the intelligent e-business on the semantic web, there is a need for semantic level inference to the web information. To satisfy the need, we will review the knowledge/resource representation on the semantic web such as RDF, Ontology and Conceptual Graph (CG), and then discuss about the natural language (NL) inference. The result of this research could support a natural interface for the semantic web. Furthermore, we expect that the NLQF can be used in the semantic web-based business communications.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11b
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• pp.1427-1430
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• 2002

SNMP(Simple Network Management protocol) 기반 망 관리 에이전트 기능을 구현하기 위해서는 에이전트 시스템 특성에 따른 표준 MIB(Management Information Base)을 구현하여 SNMP가 사용할 수 있도록 하여야 한다. 이때, SNMP 망 관리 에이전트 기능에 구현된 MIB은 망 관리를 위해 해당 객체(object)에 접근할 수 있는 가상의 정보일 뿐 MIB에 정의된 각 객체에 대한 값은 해당 MIB 정보를 제공하는 시스템 기능(이하 시스템 기능이라 함.)에서 제공된다. 이때 SNMP 망 관리 에이전트 기능에서는 시스템 기능과 어떠한 정합 방법으로 통신하는가 하는 문제는 시스템 구현 사항이다. 일반적으로 시스템 기능에서 각 객체별로 접근 가능한 API를 제공하여 SNMP 망 관리 에이전트 기능에서 이를 이용하도록 구현되어 있다. 본 논문에서는 이러한 방식의 문제점을 살펴보고, 테라 라우터에 구현하는 SMUX(SNMP Multiplexing) 프로토콜 정합 방법 및 IPC 정합 방법을 설명한다. 또한 IPC통신시 재사용 가능한 메시지 구조를 제안한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.05c
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• pp.2061-2064
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• 2003

PKI(Public Key Infrastructure)기반의 발전으로 인터넷뱅킹, 증권거래시스템, 전자메일, 전자입찰, 전자민원 등 신원확인이 요구되는 어플리케이션에 전자서명과 암호가 적용되고 있다. 각 어플리케이션은 라이브러리를 호출하여 전자서명과 검증, 암호와 복호를 수행한다. PKI기반의 어플리케이션 개발자는 상이한 인증, 암호API(Application Programming Interface)를 호출해야 하며, 이는 프로그램의 복잡도를 증가시킨다. 개발언어와 환경에 따라서 상의한 라이브러리를 사용해야 한다. 제안하는 PKI 에이전트는 개발언어와 어플리케이션에 독립적으로 인증, 암호기능을 수행하고 견과만을 리턴한다. 따라서 어플리케이션은 인증과 암호가 필요한 시점에 검증 에이전트를 호출하게 됨으로써 프로그램의 복잡도를 줄이고 어플리케이션의 안정성을 향상시킨다.

• Korean Journal of Computational Design and Engineering
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• v.11 no.5
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• pp.365-374
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• 2006

The ubiquitous environment is to support people in their everyday life in an inconspicuous and unobtrusive way. This environment requires information such as the person, his/her preferences, and habits which is available in the ubiquitous system. In this paper, we propose the context aware system that can provide the tailored information service for user in ubiquitous computing environment. Our system architecture is divided into 4 domain models such as context awareness, presentation, interface and inference domain. Each domain model can perform some predefined tasks independently. And we suggest the hybrid algorithm combined with fuzzy and Bayesian method in order to reason what is the suitable information for user. We show the possibility for the real application through applying the system to the TGA (Tour Guide Assistant) for Kyoungju historical site.