• Title/Summary/Keyword: brightness control

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DEINKING OF COLORED OFFSET NEWSPRINT WITH ENZYME TREA TMENT IN COOPERATION WITH ULTRASONIC WAVE

  • Yimin XIE;U, Hong-W;Yanming LAI
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 1999.11b
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    • pp.149-152
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    • 1999
  • A new process for deinking of colored offset newsprint, i.e. enzyme treatment in cooperation with ultrasonic wave was developed in the present study. The physical characteristics such as fiber length, coarseness, crystallinity index of the deinked pulps were investigated and the sugar residues released from the treatment were analyzed. It was found that colored offset newsprint could be deinked effectively by cellulase treatment when ultrasonic wave was applied. The brightness increased by 5% ISO over that of control experiment and the pigment content was reduced markedly. Though the ultrasonic wave had little effect on the strength and crystallinity of the pulp, the treatment of enzyme combined with ultrasonic wave reduced the coarseness and fiber length to some extent. It was also found that ultrasonic wave could accelerate the hydrolysis of cellulose and hemicellulose during the cellulase treatment.

Development of Auto-hydrolysis Method for Preparing Cotton Linter Regenerated Fibers of Textile Fabrics (방직용 재생펄프 제조를 위한 면 린터의 자기가수분해 공정 개발)

  • Sohn, Ha Neul;Park, Hee Jung;Seo, Yung Bum
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.47 no.6
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    • pp.81-88
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    • 2015
  • The molecular weight (MW) and crystallinity of cotton linter need to be controlled to be dissolved well in N-methylmorpholine N-oxide (NMMO) solvent for manufacturing regenerated fibers of clothing fabrics. Electron beam irradiation or sulfuric acid pre-treatment followed by alkaline peroxide bleaching has been used to control MW effectively and to improve brightness of cotton linter. Auto-hydrolysis of cotton linter without electron beam irradiation or chemical pre-treatment was found to be effective as an alternative pre-treatment method. Removal of metal ions, that hampered dissolution of cotton linter by NMMO, was also investigated when the auto-hydrolysis was accompanied with ionic polymers and chelating agent.

A Study on Lighting Emergency Lamp using Photovoltaic Generation System (태양광발전시스템을 이용한 유도등용 헝광램프의 점등에 관한 연구)

  • 이상집;성낙규;이승환;오봉환;백동현;이훈구;한경희
    • Fire Science and Engineering
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    • v.14 no.1
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    • pp.22-26
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    • 2000
  • Emergency lamp is installation usage on an emergency situation or firing. It's an offer at least of brightness. It's lighting to common source usually. It's transferred to reserve battery on power stoppage. This emergency lamp is lighted from solar cell system. The solar cell should be operated at the maximum power point. This paper proposes the new control method that half-bridge inverter using the solar cell can operate emergency lamp.

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Technology Trend and Requirement of Mobile Displays Using Low-Temperature Poly-Si (LTPS) Technologies

  • Kwon, Oh-Kyong
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.409-412
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    • 2007
  • A lot of research for system-on-panel(SOP) have been done to integrate display systems including data driver, gate driver, timing controller, DC-DC converter, and smart functions such as embedded touch screen, ambient brightness sensing and luminance control, finger printing on the glass. Recently, the cost of an one-chip driver IC with various functions has decreased rapidly, and new mobile display interface technologies have been introduced. So it is necessary to examine the feasibility of SOP for practical mobile applications. In this paper, we will re-examine LTPS technologies for mobile displays in terms of various aspects and discuss the practical limitations on SOP technology and future technology trend of mobile displays.

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Design and Implementation of Automatic System in Car Based on Zigbee (지그비 기반 차량 자동화 시스템의 설계 및 구현)

  • Kim, Nam-Hee;Lee, Jong-Chan
    • Convergence Security Journal
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    • v.8 no.2
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    • pp.27-34
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    • 2008
  • In this paper, we designed and implemented mobile object automatic system based on senor networks for telematics. For developing this system, we gather the various sensing data through wireless communication method using zigbee sensor networks and analyze them in monitoring equipment. And we enable the driver to recognize the car state information on the whole by interfacing analyzed data to telematics unit. And, we implemented automatic controller that can control temperature and humidity in car automatically by actuating air conditioner based on the data that was monitored throughout temperature sensor, humidity sensor and brightness sensor based on sensor networks.

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The Enhanced LED Dispensing Processing System (개선된 LED 토출 공정 시스템)

  • Cho, Do-Hyeoun;Lee, Jong-Yong
    • 전자공학회논문지 IE
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    • v.45 no.4
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    • pp.42-46
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    • 2008
  • LED's production does Die bonding and Wire bonding on L/F board, and do epoxy dispensing to protect LED Chip and improve brightness. In this paper, we propose and realize a x-y-z axis robot mechanism detecting automatically eopxy's amount being filled, control data of pressure and time by the quantity automatic revision, and epoxy of the schedule amount dispensing.

A Study on the Optical Arrangement and Color Control of LED Lamps for illumination Applications (LED 조명 광원의 광학적 배치 및 광색 제어에 관한 연구)

  • 박준석;김광헌;여인선
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.15 no.2
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    • pp.7-12
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    • 2001
  • In this paper, the optical arrangement of LED lamps was studied using an optical design software for illumination applications. A standard source was constructed, and then simulated its light distribution characteristics of the basic arrangements by shape, by angle, and by displacement. And the color variation circuit was constructed to obtain stabilized light and color output in consideration of the electrical and optical characteristics of high brightness RGB LEDs.

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Inverter Design and Control for Driving Electro-Luminescence Sheet (EL 시트 구동을 위한 인버터의 설계 및 제어)

  • Lee, Seung-Yo
    • The Transactions of the Korean Institute of Power Electronics
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    • v.14 no.5
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    • pp.355-364
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    • 2009
  • Electro-Luminescence (EL) sheets have been widely used in lighting displays, mainly used as advertisement panels. To drive the ELs in optimal conditions, it is required to understand the load profile of the EL. Hence, in this paper, a modeling for an EL sheet was performed to analyze the load characteristics of the EL. Based on the extracted model of the EL, a topology for inverter system was chosen and the optimal design parameters were obtained. The validity of the designed EL driver system was verified through computer simulations and experiments.

Characteristic Analysis of RGB-LED Backlight for Current and Temperature Variations (RGB형 LED Backlight의 전류 및 온도 변화에 따른 특성 분석)

  • Lim, S.H.;Lim, J.G.;Shin, H.B.;Chung, S.K.;Shin, M.J.;Sohn, S.G.
    • Proceedings of the KIPE Conference
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    • 2007.07a
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    • pp.244-246
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    • 2007
  • The LCD backlight technique using light-emitting diode(LED) has been studied in the recent backlight market. The white light is need for LCD backlight and it is generally implemented by combining the RGB-LEDs to obtain the high brightness. However, RGB-LEDs have different color characteristics for the current and temperature variations, which results in the color shift problem. The color shift characteristics of RGB-LEDs for the current and temperature variations are investigated in this paper. This result can be used to control the color of backlight system using RGB-LEDs.

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A New PCM Inverter for Brightness Control of 32inch LCD Backlight (32인치 LCD Backlight의 휘도 제어를 위한 새로운 PCM 방식 인버터)

  • Lee, Jae-Kwang;Han, Sang-Kyoo;Roh, Chung-Wook;Hong, Sung-Soo;SaKong, Sung-Soo;Kim, Jin-Wook;Lee, Hyo-Bum
    • Proceedings of the KIPE Conference
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    • 2007.07a
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    • pp.372-374
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    • 2007
  • 본 논문에서는 LCD Backlight를 위한 기존 Phase shift Full bridge 인버터 방식을 검토하여, 이를 바탕으로 기존의 Full bridge Inverter 토폴로지와 전력 시스템은 동일하게 가져가고 좀 더 나은 성능을 위해 독자 기술의 새로운 구동 및 제어 방식을 구현하고자 한다. 인버터 부의 최적 동작을 위해 인버터 구동 신호의 주파수와 시비율을 고정하는 대신 펄스 개수를 제어하는 새로운 Pulse Count Modulation (PCM) 방식을 제안하며 이론적 및 실험적 검증을 통해 제안된 방식의 우수성을 확인한다.

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