• Title/Summary/Keyword: Ambient Light

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Elimination of the Red-Eye Area using Skin Color Information

  • Kim, Kwang-Baek;Song, Doo-Heon
    • Journal of information and communication convergence engineering
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    • v.7 no.2
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    • pp.131-134
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    • 2009
  • The red-eye effect in photography occurs when using a photographic flash very close to the camera lens, in ambient low light due to in experience. Once occurred, the photographer needs to remove it with image tool that requires time consuming, skillful process. In this paper, we propose a new method to extract and remove such red-eye area automatically. Our method starts with transforming ROB space to YCbCr and HSI space and it extracts the face area by using skin color information. The target red-eye area is then extracted by applying 8-direction contour tracking algorithm and removed. The experiment shows our method's effectiveness.

LED array design for optimal combination of plant grown (식물재배를 위한 최적LED 배열조합설계)

  • Lee, Sungwon;Park, Sekwang
    • Journal of Plant Biotechnology
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    • v.41 no.3
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    • pp.123-126
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    • 2014
  • This paper is suitable for household plant factory by design and using both energy-saving LED and solar technology. Conventional household plant factory only depending on natural sunlight is sensitive for the change of external environment. Another a big problem of conventional common household plant factory is large power consumption. Recently interest in wellbeing food such as chemical-free is increased abruptly. To solve these two problems, this paper describes hybrid type of household plant. In particular, reducing the power photosynthesis photon flux density (PPFD) is kept uniform to enhance the growth of the plant. Ambient light sensor is adopted for the control of proper combination of sunlight and LED to keep PPFD constant.

Droplet size measurement using image processing method (이미지프로세싱 기법을 이용한 액적크기 측정)

  • Lim Byoungjik;Jung Kihoon;Khil Taeock;Yoon Youngbin
    • Journal of the Korean Society of Visualization
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    • v.2 no.1
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    • pp.25-31
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    • 2004
  • Droplet size is one of the most important parameter which controls the performance of the combustion system using liquid fuel or oxidizer. Droplet formation and its size are mainly affected by the injection velocity and ambient gas density. Recently, droplet size measurement was conducted by PDPA or Malvern particle analyzer using laser light. But at this paper image processing method was developed to measure droplet size. And its validation was investigated with reticle.

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Analysis for fire suppression efficiency of intermittent water spray pattern with FDS (FDS를 이용한 교번식 미분무방식의 소화 성능 분석)

  • Jee, Moon-Hak;Lee, Byung-Kon
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2008.04a
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    • pp.200-203
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    • 2008
  • Water mist fire suppression system utilizes the fire suppression features such as cooling of fire source, dilution of ambient oxygen, and shielding of radiation heat with the evaporation of microscopic water droplets. The momentum of water mist is relatively low and the infiltration of water mist to the fire source is not effective. In addition to lower penetration force, the evaporated water vapor is liable to decline to limited portion of fire source due to its light weight and sparse density. On the other hand, the cycling water mist system is expected to improve the penetration force of water mist as well as the dilution coverage capability with the stratified spray characteristics. At this paper we present the analyzed fire suppression capability of intermittent water spray pattern by use of FDS which is computational fire dynamics fire model. We expect this analysis shall be supportive to the development of the prototype of water mist nozzle.

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Study of Photocatalytic Activity and Phostability of ZnO Particles Coated with UV-stable Polydimethylsiloxane

  • Jeong, Myung-Geun;Seo, Hyun-Ook;Kim, Kwang-Dae;Kim, Dae-Han;Kim, Young-Dok;Lim, Dong-Chan
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.188-188
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    • 2012
  • ZnO particles with a size range of 50-150 nm were coated with polydimethylsiloxane (PDMS) with a thin film thickness of 3-4 nm using a simple ambient-pressure chemical vapor deposition methods. Surfaces consisting of the PDMS-coated ZnO nanoparticles were found to be superhydrophobic with a water contact angle higher than $160^{\circ}$. The superhydrophobicity was sustained in the presence of UV light. Photocatalytic activity and photocorrosion of ZnO were nearly completely quenched in the presence of PDMS coating. It is suggested that our PDMS-coating can be of potential interest for the application of ZnO in UV protection agents and energy and electronic devices.

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Properties of the Electrodeless Discharge Lamp Using H-Discharge (H-방전을 이용한 무전극 방전 램프의 특성)

  • Kim, Tae-Hyoun;Park, Tong-Wha
    • Proceedings of the KIEE Conference
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    • 1998.07e
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    • pp.1708-1710
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    • 1998
  • In this study, several experiment is executed to analyze properties of Electrodeless Discharge Lamp using H-Discharge. 1. The operating frequency of this lamp is $2.45{\sim}2.65$[MHz] 2. The color of light is mild-white. And, it is shifted in the direction of red in low temperature. 3. In ambient temperature under $10^{\circ}C$, luminous efficiency is decreased precipitously. Therefore, research for improvement discharge-characteristic in low temperature need. 4. Discharge-characteristic stable between $160{\sim}240$[V]. And, luminous output is inverse proportion to coil-voltage. 5. When input-voltage is decreased continuously unstable section exist.

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A Three-dimensional Transparent Display with Enhanced Transmittance and Resolution Using an Active Parallax Barrier with See-through Areas on an LCD Panel

  • Park, Minyoung;Choi, Hee-Jin
    • Current Optics and Photonics
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    • v.1 no.2
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    • pp.95-100
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    • 2017
  • The transmittance of the three dimensional (3D) transparent display is an important factor and can be enhanced by adding a see-through area to the displayed 3D image in order to transmit an ambient light with maximum transparency. However, there is a side effect that the perceived 3D resolution can be degraded due to the see-through area. In this paper, we propose an advanced method to resolve the above trade-off relation between the transparency and the 3D resolution by using an active parallax barrier (PB) with a see-through area. The experimental results are also presented to prove the proposed principle.

Trends on Non-contact Haptic Display Technology (비접촉식 촉감 디스플레이 기술 동향)

  • Hwang, I.;Kim, J.R.;Yun, S.
    • Electronics and Telecommunications Trends
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    • v.33 no.5
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    • pp.95-102
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    • 2018
  • With the widespread use of multifunctional devices, haptic sensation is a promising type of sensory channel because it can be applied as an additional channel for transferring information for traditional audiovisual user interfaces. Many researchers have shed new light on non-contact haptic displays for their potential use on ambient and natural user interfaces. This paper introduces several of the latest schemes for creating a mid-air haptic sensation based on their transfer medium: ultrasonic phased arrays, air nozzles, thermal and plasmonic lasers, and electromagnets. We describe the principles used in delivering haptic sensation in each technology, as well as state-of-the-art technologies from leading research groups, and brief forecasts for further research directions.

Luminescence Characteristics of Red Light Emitting (YVO4:Eu Thin-Film Phosphors Deposited on Si Substrate Using Pulsed Laser Deposition

  • Kim, Dong-Kuk;Kang, Wee-Kyung
    • Bulletin of the Korean Chemical Society
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    • v.25 no.12
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    • pp.1859-1862
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    • 2004
  • Europium doped yttrium vanadate ($YVO_4$:Eu) phosphor thin films were grown using a pulsed laser deposition (PLD) technique on silicon substrate. The structural characterization carried out on a series of ($YVO_4$:Eu films at post annealing temperature in the range of 550 $^{\circ}C$-1150 $^{\circ}C$ indicating that films were preferentially (200) oriented at post annealing temperature above 950 $^{\circ}C.$ Photoluminescence of thin film increased with the increase of post annealing temperature and ambient oxygen pressure though the thin film has the powder-like surface morphology at oxygen pressure above 200 mTorr. Photoluminescence decay from $^5D_1$ level of $Eu^{3+}$ show the great concentration dependency, which can be used as a good parameter to control the composition of ($YVO_4$:Eu thin film.

A study on the anti-freezing of light weight electric traction system testing road (경량전철 시스템 선로 결빙방지에 관한 연구)

  • Woo, Jae-Ho;Han, Kyu-Il;Kim, Jong-Soo
    • Proceedings of the KSME Conference
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    • 2008.11b
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    • pp.2256-2261
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    • 2008
  • The electric snow melting and deicing system by electric heating cable which is adopted in this study is a part of road facilities to keep surface temperature of the road higher than freezing point of water for melting the snow or ice accumulated on it. The electric heating cables are buried under paved road at a certain depth and a certain pitch and operated automatically and manually. Design theory, amount of heating, and installation standard vary according to economic situation, weather condition, and installation place. A main purpose of this study is figuring out the appropriate range of required heat capacity and installation depth and pitches for solving snowdrifts and freezing problems with minimum electric power consumption. This study was performed under the ambient air temperature($-2^{\circ}C$, $-5^{\circ}C$), the pitches of the electric heating cables (200 mm, 300 mm), heating value ($250\;W/m^2$, $300\;W/m^2$, $350\;W/m^2$).

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