• 대한안전경영과학회지
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• 제12권4호
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• pp.61-66
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• 2010

Organic light emitting diode(OLED) has been developed fast from 1963 when electric light emitting phenomenon was discovered. PMOLED(passive matrix OLED) is producted earlier than AMOLED(active matrix OLED). PMOLED is mainly mounted at sub display, but AMOLED is mounted at main display. Nowadays AMOLED is expanded to PMP(portable multimedia players), navigation and TV market. Even thought OLED's market is opening to many applications, OLED's life is worried until now. If we know about OLED's real life, we need time to test so much time over 20,000hrs. Realistically, there is difficult to test such as long time with products from the information-technology sector having a short life cycle. In this paper, we study about OLED's accelerated test to reduce life test by current. We can design OLED's accelerated life model by the result of test. The model consists of design variables like ratio of light emitting, organic material structure, condition of aging, etc. In conclusion, this model can be applied to study about organic material, machine and manufacturing process etc, and also it's possible to develop a method of manufacturing process & materials, so we need to study on the subject of this paper continuously.

• 한국통신학회논문지
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• 제22권5호
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• pp.956-966
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• 1997

단일 스테이지 스위칭 구조를 갖는 홀로그래픽 크로스바에 의한 동적인 자유공간 광연결을 실험하였다. 동적인 동작을 위해 전기적인 주소지정방식의 액정 공간광변조기와 회절격자가 매트릭스-매트릭스 크로스바에서의 고정적인 홀로그램을 대신하여 사용되었다. 회절격자는 규칙적인 셀들로 이루어졌으며 각 셀마다 서로 다른 위상지연 정도를 갖는다. 이러한 화소형 위상격자 배열을 공간광변조기에 띄어 입력빔의 방향으로 편향시키거나 여러 빔으로 분리한 후 원하는 위치로 빔의 방향을 조종한다. 이러한 실험결과 컴퓨터와 공간광변조기, 위상형 회절격자를 이용하여 자유공간 광연결이 동적으로 수행됨을 보였다.

• 세라미스트
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• 제10권3호
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• pp.48-54
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• 2007

Glass-ceramics transparent above $10\;{\mu}m$ in the infrared, have been synthesized. They are based on germanium and antimony sulphides or selenides associated to alkali halides. They are prepared by heating glass samples at temperatures above the glass transition, as a function of time. Ceramisation can be controlled, so that sub-100 nm crystals are generated in the glass matrix. Then, low light scattering is achieved and the transparency window of the original glass is maintained. When gallium sulphide is added, glass ceramics can be doped with rare-earth ions. Emissions from the $^4F_{3/2}$ and $^4I_{13/2}$ of $Nd^{3+}$ and $Er^{3+}$ ions, respectively, are more intense in glass-ceramics, as compared to their vitreous counterpart. Examination of band profiles and decaytimes show that rare-earth ions are embedded in both crystalline and glassy environments.

• 대한전기학회논문지:시스템및제어부문D
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• 제53권1호
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• pp.10-15
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• 2004

We present a state-space approach to make non-square linear systems strictly passive by using an input-dimensional parallel feedforward compensator. A necessary and sufficient condition for the existence of the parallel feedforward compensator is given by the static output feedback formulation, which enables to utilize linear matrix inequality. By modifying the structure of the compensator the additional technical assumption in the previous result [1] is removed. The effectiveness of the proposed method is illustrated by some numerical examples which can be stabilized by the proportional-derivative (PD) and proportional-derivative-integral (PID) control laws. The proposed control scheme can successfully replace the measurements of derivative terms in the control laws.

• 제어로봇시스템학회논문지
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• 제5권3호
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• pp.314-323
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• 1999

This paper introduces a methodology of active calibration of a camera pose (orientation and position) using the images of cylindrical objects that are going to be manipulated. This active calibration method is different from the passive calibration where a specific pattern needs to be located at a certain position. In the active calibration, a camera attached on the robot captures images of objects that are going to be manipulated. That is, the prespecified position and orientation data of the cylindrical object are transformed into the camera pose through the two consecutive image frames. An ellipse can be extracted from each image frame, which is defined as a circular-feature matrix. Therefore, two circular-feature matrices and motion parameters between the two ellipses are enough for the active calibration process. This active calibration scheme is very effective for the precise control of a mobile/task robot that needs to be calibrated dynamically. To verify the effectiveness of active calibration, fundamental experiments are peformed.

• Journal of Information Display
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• 제3권4호
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• pp.1-3
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• 2002

The antiferroelectric liquid crystal display (AFLCD) is a unique display that can at demonstrate a moving image perfectly the passive matrix driving scheme. We optimised driving the waveform and introduced a dual-driving method. Also, by improving this driving method and using line inversion method, we realize the AFLC display of high image quality with $160(RGB){\times}240$, 32768 colors, crosstalk free and flicker free contrast ratio is greater than 60:1, and the brightness is above 200 $cd/m^2$.

• 조명전기설비학회논문지
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• 제27권7호
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• pp.76-81
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• 2013

This paper presents an effective pedagogical method for nodal analysis in linear circuit. In the proposed method, basic equations are built only for passive elements and independent current sources. And then, the basic equations are modified by considering other sources such as voltage sources and dependent current sources. In the proposed method, the equations are presented in form of a matrix and a vector of which elements are built systematically by considering every element in a circuit one by one. This make the proposed method easy to apply to intricately composed circuit and easy to solve the final simultaneous equations and easy to realize as computer program for nodal analysis and easy to memorize compared to the conventional method.

• KIEAE Journal
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• 제16권1호
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• pp.95-101
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• 2016

This study aims to analyze the satisfaction targeted community space for public rental housing tenants a real community space. and community space is analyzed only through the factor analysis of the effects of satisfaction, multiple regression analysis etc. As a result, the space community and public rental housing will only affect the satisfaction, factors affecting such analysis was 'common space', 'exercise place', 'resting place'. Thus, a variety of political and institutional efforts and practical research for interactive spatial planning public rental housing estates satisfaction for the improvement and community activation moving away from passive concept of the one-way ever to supply that community space in the past, provider centers and considering the tenant characteristics is required.

• 반도체디스플레이기술학회지
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• 제4권1호
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• pp.17-21
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• 2005

We presented a new method to obtain four speckle interferograms with relative phase shift of $\pi$/2 by passive devices such as waveplate and polarizer, calculate the phase at each point of the speckle interferogram in shearography using Wollaston prism, which can be applied to the deformation evaluation of semiconductor devices, and theoretically demonstrated the feasibility of the proposed method by Jones matrix.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.871-875
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• 1996

The Output feedback linear quadratic regulator control is applied to the design of active suspension system using 7 DOF full car model. The performance index reflects the vehicle vertical movement, pitch and roll motion, and minimization of suspension stroke displacements in the rattle space. The elements of gain matrix are approximately decoupled so that each suspension requires only local information to generate the control force. The simulation results indicates that the output feedback LQ controller is more effective than purely passive or full state feedback active LQ controllers in following the road profile at the low frequency range and suppressing the road disturbance at the high frequency ranges.