• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.293-293
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• 2006

Self-assembled nanostructures of block copolymer thin films have gathered significant attention due to their potential applications as templates for nanofabrication. However the lack of a robust strategy to control the structure formation in thin film geometries has been considered a major obstacle for the practical application. In this presentation 'epitaxial self-assembly' will be introduced as a successful strategy to control the self-assembled nanostructure of block copolymer. Chemically patterned surfaces prepared by advanced lithographic techniques successfully registered nanodomains in block copolymer thin film without any single defect over an arbitrarily large area.

• 한국과학교육학회지
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• 제12권3호
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• pp.77-89
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• 1992

According to many previous researches on the students' physics conceptions, in spite of school science learning the students' preconceptions were either not changed or reinforced. Although many researchers argued that the presentation of conflict situations which can not be explained by the students' preconceptions is prerequisite to their conceptual changes, some other researchers argued that such a presentation could be useless. In this study, a model of students' conceptual change in physics, which encourages students to recognize actively the conflicting situations and to control the process of their conceptual changes, was developed. In this model, the critical discussion on rival concepts and the reflective thinking were regarded as two important factors for students' conceptual changes.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2010년도 제42차 하계학술발표논문집 18권2호
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• pp.241-244
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• 2010

본 논문은 모바일 환경에서 Handoff 상에서 부드러운 스트림(stream) 재생(presentation)을 위한 멀티미디어 동기화 기법을 제안한다. 모바일 환경에서 자주 발생되는 Handoff는 베이스스테이션이 변경되므로 해서 베이스스테이션에 저장되어 있는 멀티미디어 스트림을 잃어버리게 된다. 이러한 단점은 스트림의 재생시 끊기게 되어 멀티미디어 스트림이 낮은 QoS를 갖게 된다. 본 논문에서는 멀티미디어 동기화 기법으로 핸드오프를 제어하는 방법을 제안하였다. 분석결과, 제안된 기법은 기존의 기법보다 미디어 스트림의 끊김없는 재생(stream of continuous play-out)을 제공하는 것뿐만 아니라 패킷의 높은 재생률(play-out rate)과 낮은 손실률(loss rate)을 보였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전력기술부문
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• pp.144-147
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• 2006

A proportional intergral (PI) control strategy is commonly used for constant current and extinction angle control in a HVDC (High Voltage Direct Current) system. A PI control strategy is based on a stactic design where the gains of a PI controller are fixed. Since the response of a HVDC plant dynamically changes with variations in the operation point a PI controller performance is far from optimum. The contribution of this paper is the presentation of the design of a rough set based, fuzzy adaptive control scheme. Experimental results that compare the performance of the adaptive control and PI control schemes are also given.

• 대한전기학회논문지
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• 제40권6호
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• pp.567-573
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• 1991

Full direct digital control of induction motor driver is implemented with a minimal hardware structure. This paper deals with the presentation of a low-cost single-chip microprocessor-based control system for three-phase PWM generation and vector control that control speed of the induction motor using the field-oriented control method. Rotor flux is estimated using the indirect sensing method based on the rotor circuit equation in the synchronously rotation reference frame, and slip angle and rotor position are calculated from rotor angular velocity and stator current. Through simulation and experiment, it is shown that the proposed scheme gives good static and dynamic performance to the induction motor drive.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1599-1600
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• 2007

The DTL water skid cooling system and Resonant Control Cooling Systems (RCCS) will employ a control system that can be operated by a local, programmable logic controller (PLC), interfaced through a touch screen interface, mobile alarm SMS server system, or it can be operated through the PEFP global control system network. The RCCS is implemented using Experimental Physics and Control System (EPICS) based hardware and software and is integrated with other networked PEFP EPICS systems. This presentation discusses the features of the local control system.

• Journal of Electrical Engineering and Technology
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• 제5권1호
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• pp.61-69
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• 2010

This paper presents a study of a DFIG wind power generation system for real-time simulations. For real-time simulations, the Real-Time Digital Simulator (RTDS) and its user friendly interface simulation software RSCAD are used. A 2.2MW grid-connected variable speed DFIG wind power generation system is modeled and analyzed in this study. The stator-flux oriented vector control scheme is applied to the stator/rotor side converter control, and the back-to-back PWM converters are implemented for the decoupled control. The real-wind speed signal extracted by an anemometer is used for a realistic, reliable and accurate simulation analysis. Block diagrams, a mathematical presentation of the DFIG and a control scheme of the stator/rotor-side are introduced. Real-time simulation cases are carried out and analyzed for the validity of this work.

• 한국환경교육학회지:환경교육
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• 제20권2호
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• pp.25-35
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• 2007

The purpose of this study was to investigate the effect on the achievement of knowledge by animation-based learning program(ALP) in environmental education. The topic covered by ALP was "meaning and kinds of alien animals and plants". Four classes were selected and divided into two groups. The one was control group, and the other was treatment. 121 female the eighth graders(60 control and 61 ALP students) were piloted. Whereas control students learned using Powerpoint presentation-based materials, ALP students learned using web-based flash animations and animated database with images and movie clips. The score of knowledge achievement of ALP students was compared to control group students using ANCOVA, and then the score of ALP students was significantly higher than that of control group students(p<0.05). The ALP using animations and animated database was effective on the understanding of the alien animals and plants.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.3113-3113
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• 2001

Some two years ago our company undertook a project on manufacturing network rationalization to maximize competitiveness through continuous improvement in manufacturing efficiency. One key outcome was the recognition of the benefits that could be derived from timely application of new technology or novel use of existing technologies and even more importantly the need to develop company wide strategies to maximize the impact of such applications. As a direct result an exercise was undertaken to identify the ten most promising technologies from a list of literally hundreds seen as having the capability of making a rapid impact on the manufacturing initiative. One of the outcomes of this exercise was the identification of Near Infrared Spectroscopy as a pivotal technology for improving process understanding, performance, and control to deliver consistent product quality cost effectively with broad applicability across our product range. While NIR had been in use in targeted areas on some of our sites for some years our new challenge was to develop a strategy to extend NIRs application, initially over 17 manufacturing sites, while concurrently expanding the NIR skill base company wide to ensure that the return on initial investment could be further maximized as shared applications across the remaining sites as required. This presentation will provide an overview of how life cycle based user requirement specifications were developed covering: ㆍSpectrophotometers ㆍSample interfaces ㆍSoftware ㆍEquipment and Software qualification ㆍCalibration transfer ㆍ Ease of developing effective user interfaces and control for applications transferred to a production area ㆍUser training ㆍWorld wide support The presentation will also describe the process adopted for vendor selection to ensure maximum utilization of the existing company wide NIR skill base and its future development to expedite applications of the technology in development, quality control and production areas.

• Journal of Oral Medicine and Pain
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• 제32권1호
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• pp.81-90
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• 2007

2005년 9월부터 2006년 8월까지 부산대학교병원 구강내과 구강안면통증 클리닉에 측두하악장애를 주소로 내원한 재발환자 33명과 초진환자 32명(대조군)을 대상으로 사회적 재적응 평정척도 설문지를 이용하여 생활변화를 조사 분석한 결과 다음과 같은 결론을 얻었다. 1. TMD 재발환자와 대조군의 생활변화량, 즉 LCU 총점은 $7{\sim}12$개월 이내에는 각각 평균 51.61점과 20.38점으로 재발군이 대조군에 비해 유의한 차이를 나타냈다(P<0.05). 2. TMD 재발환자군은 최근 1년간 생활상의 변화를 대조군에 비해 좀 더 많이 경험하는 경향을 보였다. 3. 연령 및 학령에 따른 TMD 재발군과 대조군의 차이와 고령층과 저령층간 생활변화의 차이는 인정할 수 없었다. 4. 미혼자군과 기혼자군간 생활상의 변화에 유의한 차이는 인정할 수 없었다.