• Title/Summary/Keyword: Radiant Energy

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Light Pollution of Outdoor Lighting in Mokpo-si (건강한 야간환경 조성을 위한 목포시 옥외조명의 빛공해 평가)

  • Kong, Hyo Joo;Lee, Jin Seoung;Kim, Jeong Tai
    • KIEAE Journal
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    • v.9 no.6
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    • pp.45-50
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    • 2009
  • Nowadays, the lighting of urban nightscape has become important for improvement in city. Lighting the outdoor is different that lighting an interior. Outdoor lighting designs should be designed to minimize glare, light trespass, light clutter and energy conservation to avoid light pollution. Mokpo city launched into a large scale project of the city beautification using outdoor lighting. However, outcomes of outdoor lighting project have faced strong opposition from environmental groups. This study aims to analyze the light pollution of outdoor lighting in Mokpo-si for creating a health night environment. The Radiant Imaging Prometric-1400 was used to measure the luminance of Yudal Mountain, Goha Island and Luminarie Street. The result showed that the all the outdoor lighting produce light pollution and some places like mountain and island did not need a lot of lighting all the time.

Improving Electromagnetic Compatibility of the Infrared Flame Detector (적외선식 불꽃감지기의 전자파 적합성 개선)

  • Song, Hyun-Seon;Lee, Yeu-Yong
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.28 no.1
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    • pp.88-95
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    • 2014
  • The infrared, flame detector uses to detect fire situation from the characteristics of fire sources radiant energy. But it is able to malfunction on account of susceptible to interference of various surrounding waves. This paper is designed 6 independent PCB-boards to minimize the closed loops of siginal circuit. Also considering the interaction of electric and magnetic fields, this paper is designed protecting circuit of current and voltage output to reduced electromagnetic interference. And this paper is improving electromagnetic susceptibility by ferrite bid, capacitor filter and grounding circuits.

A MATLAB-based Approach for Visualization of Human Thermal Psychology (MATLAB 기반 열심리 가시화 기법)

  • Gineesh Gopi;Mohammad F. B. Suhaimi;Seong Eun Yoon;Hyunjin Lee;Jung Kyung Kim
    • Journal of the Korean Society of Visualization
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    • v.21 no.2
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    • pp.72-82
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    • 2023
  • Effective thermal management in a battery electric vehicle (BEV) is crucial for reducing energy consumption and maximizing driving range in cold climates. Consequently, original equipment manufacturers are actively investing in the development of local heating systems. Visualizing occupant thermal behaviors or comfort can readily provide valuable insights that would substantially impact the design and control strategies of such microclimate systems. This study uses MATLAB for three-dimensional visualization of human thermal psychology. The developed program enables qualitative assessment of occupant comfort in BEVs.

Analysis of Passive Cooling Effect of the Tree by Field Observations in the Summer (하절기 단일 수목의 열 환경 관측을 통한 서열완화 효과 해석)

  • Choi, Dong-Ho;Lee, By-Yong
    • Journal of the Korean Solar Energy Society
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    • v.26 no.4
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    • pp.109-118
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    • 2006
  • The tree is regarded as an sustainable architectural outdoor design element which reduce urban heat island effect by its solar shading and evapotranspiration. This study carried out field observations of measuring thermal environment of selected tree and its ambience to determine passive cooling effects. Results from the field observations are as below; Tree-shading effect to the thermal environment can not be properly evaluated by merely measuring air temperature differences between tree-shaded space and unshaded space for the maximum temperature difference is less than $1.5^{\circ}C$. The differences of longwave radiation and shortwave radiation between tree-shaded space and unshaded space are measured. Shortwave radiation is considered as a main thermal comfort determining factor for the difference of the shortwave radiation is much bigger than that of longwave radiation. By thermal infrared image analysis, the surface temperature of the tree under strong solar radiation is measured same as ambient air temperature. By which the evapotranspiration is considered to retard tree surface temperature raising effectively.

Drying Characteristics of Red Peppers by Infrared Heating (원적외선 가열에 의한 고추의 건조특성)

  • Bae, Nae Kyung;Lee, Jong Bung;Sang, Hie Sun
    • Journal of the Korean Society of Industry Convergence
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    • v.6 no.1
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    • pp.65-71
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    • 2003
  • Infrared heating has been traditionally used in industrial applications for processes such as dehydration of food industrial. This heating method involves the application of radiation in the wavelength range of 5~50 micrometers. In this work, simultaneous heat balance equations were developed to simulate the infrared radiation heating of red peppers. The equations assume that moisture diffuses to the outer boundaries of the material in liquid form and evaporation occurs at the surface of the red peppers. Energy for moisture evaporation is supplied by the infrared radiant energy. The equations were validated with experimental data on surface temperature and average moisture content of red peppers. Average deviations of predicted surface red peppers temperature and average red peppers moisture from experimental data were 323~353K and 50~80%, respectively. The spectral extinction coefficients in the wavelength range $1.5<{\lambda}<27$ micrometer at 293K for Red Peppers were determined from results of reflection measurements and the four flux radiative heat transfer calculation. The radiation extinction coefficients were obtained from effective drying factor the temperature 373K.

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Ignition of a Vertically Positioned Fuel Plate by Thermal Radiation (열복사에 의한 수직연료면의 점화현상 해석)

  • 한조영;백승욱
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.9
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    • pp.2353-2364
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    • 1995
  • The ignition phenomena of a solid fuel plate of polymethyl-methacrylate(PMMA), which is vertically positioned and exposed to a thermal radiation source, is numerically studied here. A two-dimensional transient model includes such various aspects as thermal decomposition of PMMA, gas phase radiation absorption, gas phase chemical reaction and air entrainment by natural convection. Whereas the previous studies considers the problem approximately in a one-dimensional form by neglecting the natural convection, the present model takes account of the two-dimensional effect of radiation and air entrainment. The inert heating of the solid fuel is also taken into consideration. Radiative heat transfer is incorporated by th Discrete Ordinates Method(DOM) with the absorption coefficient evaluated using gas species concentration. The thermal history of the solid fuel plate shows a good agreement compared with experimental results. Despite of induced natural convective flow that induces heat loss from the fuel surface, the locally absorbed radiant energy, which is converted to the internal energy, is found to play an important role in the onset of gas phase ignition. The ignition is considered to occur when the rate of variation of gas phase reaction rate reaches its maximum value. Once the ignition takes place, the flame propagates downward.

Comparison of Radiation Characteristics and Radiant Quantities per unit Electrical Power between High Luminance Light Emitting Diode and Fishing Lamp light Source (고휘도 발광다이오우드와 집어등 광원의 방사특성 및 단위 전력당 방사량 비교)

  • Choi, Sok-Jin
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.41 no.6
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    • pp.511-517
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    • 2008
  • The radiation characteristics and economic efficiency of high - luminance light - emitting diodes (LEDs), a metal halide lamp, and a halogen lamp were studied to evaluate their potential as an energy-saving light source for fishing lamps. The wavelengths at which irradiance was maximum were 709, 613, 473, 501, 525, 465, 578, and 973 nm for red, orange, blue, peacock blue, green, and white LEDs, the metal halide lamp, and the halogen lamp, respectively. If the irradiance characteristics at 300-1,100 nm wavelengths are set as 100%, the irradiance rates at 381-780 nm were 99-78%, 82%, and 24% for the LEDs, metal halide lamp, and halogen lamp, respectively. The economic efficiency was superior in the order metal halide lamp, halogen lamp, peacock blue LED, and blue LED at 381-780 nm and metal halide lamp, peacock blue LED, blue LED, and halogen lamp at 480-520 nm. Based on the radiation characteristics and economic efficiency evaluated at 480-520 nm, the blue and peacock blue LED light sources can be used as energy-saving light sources for fishing lamps.

The Design of Fuse in High Efficient Inverter Control System using Ceramic Radiant Heat and Metal Film Laminated Plating (세라믹 방열과 박막 적층 도금을 이용한 고효율 인버터 제어 회로용 퓨즈 설계)

  • Kim, Eun-Min;Kim, Shin-Hyo;Cho, Dae-Kweon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.11
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    • pp.1538-1544
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    • 2014
  • In recent years, The electronic and energy industries demand low power consumption and high efficiency, so under their demands, the white goods industries which are represented for refrigerator and air conditioner system be implemented energy-saving power suppling structure with inverter control system. As inverter control system is different from step control type, when switching system is optimizing temperature control during short period, the inrush plus current can be flown in the circuit. In despite of these characteristics, there is no fuse which can be applied to this type until now. For this reason, we suggest the method of manufacturing protector in the high efficient inverter control system using the alumina-based ceramic radiated heat characteristics and metal films laminated plating. And through the evaluating electrical characteristics, we make a possible to utilize the method when designing overall fuses.

A Study on Comparison of Capacity between Wet.Dry Floor Heating Systems Using Geothermal Heat Pump (지열히트펌프를 이용한 습식.건식 바닥난방 성능평가 연구)

  • Lee, Byoung-Doo;Lee, Se-Jin;Lee, Dae-Woo;Oh, Sung-Hae;Nam, Woo-Dong
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.567-570
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    • 2009
  • The present study conducted comparative evaluation of wet dry floor heating systems using geothermal heat pump. Circulation hot water from geothermal heat pump which is $10{\sim}15^{\circ}C$ lower than that from boiler was used. In order to access indoor temperature ($25^{\circ}C$) it took 74 minutes for dry type and 247 minutes for wet type. Average floor temperature was $23.89^{\circ}C$ for wet type and $32.66^{\circ}C$ for dry type. Energy saving rate gradually increased by 66% after 138 minutes. In the results, for floor heating system using low temperature circulation water, wet type was not enough to meet stable and comfortable radiant floor heating due to low floor temperature and access time to indoor set temperature. While dry type was practicable for stable floor heating due to fast rise of indoor set temperature and comfortable floor temperature.

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A Study on the protection of false alarm in the UV/IR flame detector (불꽃 감지기에서 오동작 방지에 관한 연구)

  • Lim, Byung-Hyun;Park, Sung-Jin;Lim, Jong-Yeon;Hwang, Jong-Sun;Kim, Young-Min
    • Proceedings of the KIEE Conference
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    • 2001.04a
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    • pp.209-212
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    • 2001
  • A flame detector responds either to radiant energy visible to the human eye or outside the range of human vision. Such a detector is sensitive to glowing embers, coals, or flames which radiate energy of sufficient intensity and spectral quality to actuate the alarm. An infra-red detectors can respond to the total IR component of the flame alone or in combination with flame flicker in the frequency range of 5 to 30 Hz. A major problem in the use of infrared detectors receiving total IR radiation is the possible interference of solar radiation in the infrared region. When detectors are located in places shielded from the sun, such as vaults, filtering or shielding the unit from the sun's rays is unnecessary. In this study, we proposed method for redue a false alarm with using filtering & sensor technology for distinguish of causes of raise a false alarm and pure flame.

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