• Title/Summary/Keyword: brightness control

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A study on lighting system for LED color temperature control using wireless communication and smartphone (무선 통신과 스마트폰을 이용한 LED 색온도 제어 조명 시스템에 관한 연구)

  • Hong, Young-Jin;Lim, Soon-Ja;Lee, Wan-Bum
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.11
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    • pp.72-77
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    • 2017
  • Lighting systems in modern society has been developed using a combination of IT technology and LED lighting for the purpose of bringing about changes in human-centered natural lighting and to take advantage of the efficient management and energy saving of LED lighting. In this paper, we propose an LED lighting control system that can control the color temperature and brightness of LED lighting composed of 3000K Warm LEDs and 6000K Cool LEDs by using an Arduino Due and wireless communication technology such as Bluetooth and Zigbee. The Arduino Due allows the color temperature of the lighting to be adjusted in several steps by controlling the duty rate and enables many lights to be controlled using Zigbee communication capable of 1: N multiple communication. By using Bluetooth communication, it is possible to easily control the LED lighting by means of a smartphone application, thereby enhancing the convenience for the user. The wireless communication based LED lighting control system implemented in this study cannot only provide human-centered lighting through its color temperature control from 3067K to 5960K and illumination control, but can also reduce the power consumption and be used as a natural-friendly lighting system.

New Approach to Low NOx Combustion by Changing Combustor Pressure (연소실 압력변동을 이용한 저 NOx 연소의 새로운 접근)

  • Kim Jong Ryul;Choi Gyung-Min;Kim Duck-Jool
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.29 no.10 s.241
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    • pp.1148-1155
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    • 2005
  • In this study, the influence of changing combustor pressure on nitric oxide emission was investigated. Expansion of reaction region was more clear in the P$^{*}$ <1 conditions compared to the P$^{*}\geq1$ conditions, and it could be observed that flames are distinct in the P$^{*}\geq1$ conditions and that brightness is relative low and wide distribution is shown in the P$^{*}$ <1 conditions. In the respect of temperature distribution, narrow and high-temperature region was shown in the P$^{*}\geq1$ conditions. On the other hands, overall uniform temperature distributions were shown in the P$^{*}$ <1 conditions. Nitric oxide emission decreased with decreasing combustor pressure. This tendency was explained by the mean flame temperature distribution. Low NOx combustion is ascribed to wide-spread reaction region in the low combustor Pressure and oscillation were shown P$^{*}\leq0.97$, and strength and sizes of oscillation were more increased with lower pressure index. These results demonstrate that flame shape and nitric oxide emission can be controlled with changing combustor pressure.

Proximate Composition and Quality Characteristics of White Bread with Lentinus edodes Powder (표고버섯가루 분말 첨가 식빵의 일반성분 및 품질 특성)

  • Kim, Young-Mo
    • The Korean Journal of Food And Nutrition
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    • v.30 no.6
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    • pp.1319-1331
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    • 2017
  • The quality properties of bread with Lentinula edodes powder were investigated to find the most adequate ratio of the Lentinula edodes powder. The protein and crude fat were increased in proportion to the added quantity of Lentinula edodes powder. The amount of ash was found the most in the bread with 1% Lentinula edodes powder. It was confirmed that the volume of bread with Lentinula edodes powder decreased as the amount of the Lentinula edodes powder increased. The brightness was the highest in the control and was inversely proportional to the added amount of Lentinula edodes powder. The yellowness and redness of the dough were proportional to the added amount of Lentinula edodes powder. Total amino acids and free amino acids were found. The dough with 3% Lentinula edodes powder contained the highest amounts of both, followed by 2%, and 1%. When evaluating the length of storage, the bread's springiness and cohesiveness decreased. Regarding the taste, preference was given to the bread with 2% Lentinula edodes powder, which had the lowest value of bad odors and odd texture in the sensory test.

Chemical Properties of Artificially Buried Wood in an Intertidal Zone during the Deterioration Period

  • SEO, Sujin;KIM, Taekjoon;LEE, Jae-Won
    • Journal of the Korean Wood Science and Technology
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    • v.48 no.6
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    • pp.896-906
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    • 2020
  • Wood deterioration experiments were carried out for 6 months in an intertidal zone of South Korea to monitor the changes in the chemical properties of two types of species, Korean red pine and sawtooth oak. The results of FT-IR spectra and XRD patterns have shown that the chemical properties of the wood did not change significantly during the 6-month burial period. However, the brightness of the surface decreased after burial; the value of the sawtooth oak sample was lower than that of the Korean red pine sample owing to an accumulation of inorganic compounds in cell lumen as observed by ICP analysis. Among the inorganic compounds, sodium and sulfur concentrations increased significantly over the burial period compared with the control. Further, the maximum moisture content decreased from 199% to 136% in the Korean red pine and 62% to 60% for the sawtooth oak. Nevertheless, the major chemical composition of both the wood species did not change significantly during the 6-month burial period, whereas, the crystallinity decreased with an increasing burial period owing to an accumulation of inorganic compounds in the lumen.

Reliability Assessment Criteria of Module for the LED traffic signal (LED 교통신호등용 모듈의 신뢰성평가기준)

  • Kim, Jin-Sheon;Park, Chang-Kyu;Kim, Dae-Kyung;Jeong, Hai-Sung
    • Journal of Applied Reliability
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    • v.10 no.4
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    • pp.265-278
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    • 2010
  • Module of the LED traffic signal is the core component for the care of driver and walker. Also it is important one to control the traffic. If it is against the criteria of brightness, it is the source of the people's death and traffic congestion. Therefore, it is a list of articles desired the security of stability. However, there is not the analysis of failure and not preserve the uniformity of quality. Therefore, it is necessary to establish the criteria of appreciation for the module of the LED traffic signal to analysis the data of failure. In this paper, we investigate the performance test, environment field test and test of reliability appreciation to improve the reliability. We also set up the criteria of success decision using the real measurement data.

Development of a Measurement System for Axial-symmetric Objects Using Vision Sensor (시각센서를 이용한 축대칭 물체 측정 시스템 개발)

  • Lee, S.R.;Kim, C.S.
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.5
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    • pp.34-41
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    • 1997
  • The dimension measurement problem of products has been a major concern in the quality control in the industrial fields. A non-contacting measurement system using the vision sensor is proposed in this paper. The system consists of a CCD camera for the image capture, a frame grabber for the acquired image processing, a laser unit for the illumination, scanning unit for the measurement, and a personal computer for the geometry computation. The slit beam which is generated by passing the laser beam through a cylin- drical lens is fired to the axial-symmetric object on the rotating plate. The image of objects reflected by the laser slit beam, acquired by the CCD camera, becomes much brighter than the other parts of objects. After the histogram of brightness for the captured image is calculated, low intensity pixels are filtered out by threshold method. The performance of proposed measurement system is obtained for several different axial symmetric objects. The proposed system is verified as a good tool for measuring axial-symmetric parts in a limited condition with a minor investment cost.

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The Dimming Methods of LED Lamps to Minimize Flicker for the Broadcasting Lighting (방송조명용 LED 램프를 위한 플리커 저감 조광방식)

  • Kim, Doyoung;Yun, Janghee;Ryeom, Jeongduk
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.27 no.7
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    • pp.1-7
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    • 2013
  • LED lamps are appropriate to the light source for use in broadcasting lighting. When the lighting frequency of LED lamp is different from the shutter frequency of camera, however, the flicker appears on the moving image which is taken by the camera under the dimmed light of LED lamp with conventional dimming methods. In this study, a new dimming method for the LED lamps used as the broadcasting lighting is proposed to minimize the flicker. A lighting period in the proposed dimming method is divided into the several sub-periods which have weight of the bits. Also, the proposed dimming method has characteristics that are optimizing the turn-on timings of two LED lamps to reduce the turn-off periods of the lamps and not to overlap the turn-on periods of the lamps. In the experiments, the incidence of the flicker is taken by the camera under several lighting conditions of the conventional dimming methods and the proposed dimming method. In addition, the brightness values of the frames are obtained in the moving image, and incidence of the flicker is evaluated and compared with conventional methods. From the results, the incidence of the flicker in the proposed method is more improved than the conventional methods.

LED Driving Circuit Design of Ultrasonic Speaker System for Sign Board (싸인 보드용 초음파 스피커 상태표시를 위한 LED 구동 회로의 설계)

  • Lee, Kyung-Ryang;Yeo, Sung-Dae;Jang, Young-Jin;Cha, Jae-Sang;Kim, Jin-Tae;Shin, Jae-Kwon;Kim, Seong-Kweon
    • Journal of Satellite, Information and Communications
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    • v.8 no.4
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    • pp.17-20
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    • 2013
  • In this study, we introduce an LED Driving circuit in order that the information state can indicate audio signal gain and radiate pattern of ultrasonic speaker system for a sign board. Ultrasonic speaker system decreases energy loss and transmits the sound farther. Ultrasonic speaker having such characteristics is useful in that it can be widely used in daily life. Additionally, Proposed LED circuit indicates the information state as linear LED brightness taken from interface of ultrasonic speaker system. Designed circuit is confirmed through $0.35{\mu}m$ CMOS process by Dong-bu.

Real-Time Monitoring of Catheter-Related Biofilm Infection in Mice

  • Liu, Xu;Yin, Hong;Xu, Xianxing;Cheng, Yuanguo;Cai, Yun;Wang, Rui
    • Journal of Microbiology and Biotechnology
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    • v.25 no.10
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    • pp.1728-1733
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    • 2015
  • This study was done to establish a mouse model for catheter-related biofilm infection suitable to bioluminescence imaging (BLI). Biofilm formation of Pseudomonas aeruginosa (P. aeruginosa) Xen5 grown on catheter disks in vitro and in an implanted mouse model was real-time monitored during a 7-day study period using BLI. The numbers of integrated brightness (IB) and viable bacterial count (VBC) in the biofilm disks in vitro were highest at 24 h after inoculation; the IB of biofilm in vivo was increased until 24 h after implantation. A statistical correlation was observed between IB and VBC in vitro by linear regression analysis. The actual VBC value in vivo can be estimated accurately by IB without sacrifice. In addition, we monitored the change in white blood cells (WBCs) during infection. The number of WBCs on day 7 was significantly higher in the infection group than in the control group. This study indicates that BLI is a simple, fast, and sensitive method to measure catheter biofilm infection in mice.

The High-Reliable Image Authentication Technique using Histogram Compensation (히스토그램 보정을 이용한 고신뢰성 영상 인증 기법)

  • Kim, Hyo-Chul
    • Journal of Korea Multimedia Society
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    • v.13 no.7
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    • pp.1088-1094
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    • 2010
  • Image authentication algorithms have to discriminate forged contents in the various critical fields of military, medical services, digital documents. They must ensure perceptual invisibility and fragility against malicious attacks. It is desirable that watermarking algorithms support sufficient insertion capacity and blind feature. And, high reliable algorithms that can eliminate false-positive and false-negative errors are needed in the watermark extraction process. In this paper, we control coefficients of high frequency band in a DCT domain and compensate brightness histogram for high reliability. As a result, we found that the proposed algorithm guarantee various requirements such as perceptual invisibility with high PSNR values, fragility, high reliability and blind feature. In addition, experiment results show that the proposed algorithm can be used steganographic applications by sufficient capacity of watermark.