• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.9
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• pp.604-609
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• 2011

The increased quality of life requires indoor illumination environment to have illumination with higher intensity. The increase in indoor illumination goes hand in hand with increase in indoor heat load. Of late, the internal heat in the cooling load has been growing gradually and the proportion of the lighting load has been bigger in the cooling load. The objective of the experiment here is to estimate the proper exhaust air flow displacement to remove heat from different types of lighting equipment. The heat causing the cooling load in lighting equipment is the ratio of heat per watt and the ratio of space for heat. Experimental measurements of the constant temperature and humidity in chambers that exhaust air flow by changing the exhaust calorific value was measured. Using the Airflow exhaust heat from lighting fixture of this study should help to reduce House cooling load.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.9
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• pp.1-7
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• 2012

In this paper, we present a new lighting control method considering ambient light in addition to the required lighting illumination for efficient energy saving of a LED stand. We estimate accurate environmental illuminance using a cheap illuminance sensor by modeling measured- and actual-illuminance using quadratic polynomial approximation. The relation between PWM(Pulse Width Modulation) duty ratio and illuminance intensity is modeled by a linear model. Illumination of the LED stand is controlled by estimating the difference of required illumination and the estimated ambient illumination. The developed LED stand has reduced electric energy consumption compared with a conventional manually controlled LED stand with the same lighting source. In addition, human subject evaluation shows that the LED stand, which is applied the proposed method, is more satisfactory than conventional ones since the proposed automatic controlled illumination produce more accurately required lighting and it is convenient.

• Current Optics and Photonics
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• v.7 no.6
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• pp.755-760
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• 2023

In this paper, an illumination optical system that can mitigate the saturation phenomenon in the center of an image (caused by the typical flexible-endoscope illumination system using LEDs with Lambertian light distribution) is designed. When an LED with Lambertian light distribution is used as a light source, the amount of light in the center of the endoscopic illumination system is relatively high, compared to the periphery, causing saturation in the image. Since this phenomenon causes difficulty in detecting the patient's lesion, it is necessary to find a lighting-system design that can alleviate the saturation phenomenon. Therefore, in this paper a lighting system with bat-wing light distribution, which can lower the intensity at the center and secure the maximum amount of light at the maximum light distribution angle, is designed. In addition, to check the performance of the designed lighting system, a simulation of illumination and luminance is conducted for a system using a common aspherical lens with otherwise the same components. As a result, it is confirmed that the lighting system designed in this paper effectively reduces the luminance value at the center and secures more luminance values at the periphery than the familiar lighting system.

• Korean Journal of Environmental Agriculture
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• v.30 no.4
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• pp.382-389
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• 2011

BACKGROUND: Light-emitting diodes (LEDs) with lower electric cost and the specific wavelength have been considering as a novel light source for plant production in greenhouse conditions as well as in a closed culture system. Supplementary lighting for day-length extension was considered as light intensity, light quality, and/or photoperiod control on plant growth and development. Effects of supplementary blue or red LED radiation with lower light intensity on growth of Ageratum (Ageratum houstonianum Mill., cv. Blue Field), African marigold (Tagetes erecta L., cv. Orange Boy), and Salvia (Salvia splendens F. Sello ex Ruem & Schult., cv. Red Vista) were discussed during sunrise and sunset twilight in the experiment. METHODS AND RESULTS: Supplementary lighting by blue and red LEDs for 30 (Treatment B30; R30) or 60 (Treatment B60; R60) min. per day were established in greenhouse conditions. Photosynthetic photon flux for supplementary radiation was kept at $15{\mu}mol\;m^{-2}\;s^{-1}$ on the culture bed. Natural condition without supplementary light was considered as a control. The highest shoot and root dry weights were shown in African marigold exposed by red light for 60 min. per day. Supplementary blue and red lighting regardless of the radiation time significantly stimulated development of lateral branches in African marigold. Stem growth in Ageratum and Salvia seedlings was significantly promoted by red radiation as well as natural light. CONCLUSIONS: Extending of the radiation time at sunrise and sunset twilight using LEDs stimulated reproductive growth of flowering plant species. Different characteristics on growth under supplementary blue or red lighting conditions were also observed in the seedlings during supplementary radiation.

• Transactions on Electrical and Electronic Materials
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• v.12 no.6
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• pp.253-257
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• 2011

This study was carried out to solve problems such as radio frequency band depletion, confusion risk, and security loss in existing visible wireless communication systems, and to determine the applicability of next-generation networks. A light-emitting diode (LED) light communication system was implemented with a controlling switching light module using the ATmega16 micro-controller. To solve the existing modulation effect and disturbance in visible light communication, an integrated interface was evaluated with a driving light module and analyzes its reception property. A transmitter/receiver using the ATmel's micro-controller, high-intensity white LED-6 modules, and infrared sensor KSM60WLM and visible sensor TSL250RD were designed. An experiment from the initial value of distance to 2.5 m showed 0.46 V of the voltage loss, and if in long distance, external light interference occurred and light intensity was lost by external impact and thus data had to be modified or reset repeatedly. Additionally, when we used 6 modules through the remote controller's lighting dimming, data could be transmitted up to 1.76 m without any errors during the day and up to 2.29 m at night with around 2~3% communication error. If a special optical filter can reduce as much external light as possible in the integrated interface, the LED for lighting communication systems may be applied in next generation networks.

• Journal of Bio-Environment Control
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• v.17 no.4
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• pp.266-272
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• 2008

The aim of this study was to investigate the effect of supplemental lighting with different lighting intensity during growth on the sugar and pyruvic acid content of onion bulbs. As the result of comparison with growth, the content of pyruvic acid and sugar at harvest, supplemental lightening condition showed better growth, lower pyruvic acid content and higher sugar content than control. As to the growth at harvest according to lightening condition, 'Josaeng-ssundeobol' showed better growth as the lightening increased and 'Damrojunggab' had no difference above $12{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PAR. 'Josaeng-ssundeobol' contained much more content of pyruvic acid and sugar than 'Damrojunggab'. 'Josaeng-ssundeobol' had the lowest pyruvic acid content in $24{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PAR and 'Damrojunggab' had no difference above the $12{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PAR. The sugar content of 'Josaeng-ssundeobol' had no big difference above $18{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PAR and that of 'Damrojunggab' had no big difference above $12{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PAR. Desirable indicator to select individuals for the onion breeding is to select individuals that has low pyruvic acid content and high sweetness. Therefore, it will be possible to produce sweet onion conditioned on light supplement over $18{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PAR in 'Josaeng-ssundeobol' and over $12{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PAR in 'Damrojunggab'.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.363-366
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• 2005

In this paper, for detecting human faces under variations of lighting condition and facial expression, distance ranking feature and detection algorithm based on the feature are proposed. Distance ranking is the intensity ranking of a distance transformed image. Based on statistically consistent edge information, distance ranking is robust to lighting condition change. The proposed detection algorithm is a matching algorithm based on FFT and a solution of discretization problem in the sliding window methods. In experiments, face detection results in the situation of varying lighting condition, complex background, facial expression change and partial occlusion of face are shown

• Journal of Korea Multimedia Society
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• v.18 no.8
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• pp.988-995
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• 2015

In 2013, Academy Award for Best Animated Short Film was granted to Walt Disney's short animation, (2012). With various aspects of its excellence, I focus on the very effective use of digital lightings and underscores for storytelling as its success factors. In this respect, this paper aims at analyzing the roles of the visual factors, especially tone, contrast, etc. created by lightings, and audio factors, especially underscores, in the film's story development. I find that can be characterized by the well-built story structure with distinct three acts. The main stream of the story is expressed with the overall mood that is created by the fine adjustments of brightness of the main light, and contrast. And the direction and the intensity of the lighting successfully describe the emotions of the characters in each scene. In addition, I find that properly chosen and positioned underscores make the development of the story more dynamic and more harmonized.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11c
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• pp.632-638
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• 2000

This paper represents the characteristics of evapotranspiration rate (EVTR) and graft-taking of watermelon grafted seedlings in a graft-taking enhancement system using fluorescent lamps as artificial lighting source. Four air temperature levels of 23, 25, 27 and 29C, three humidity levels of 85, 90 and 95%R.H. and two photosynthetic photon flux (PPF) levels of 30 and 50 ${\mu}$mol m$\^$-2/ S$\^$-1/ were provided to investigate the effects of air temperature, relative humidity and light intensity on EVTR and graft-taking of grafted seedlings. EVTR of grafted seedlings increased with increasing air temperature and the passage of time after grafting. Also EVTR increased with decreasing relative humidity. As relative humidity decreased and air temperature increased, vapor pressure deficit increased and thus EVTR increased. It is required to maintain a low level vapor pressure deficit for suppressing EVTR of grafted seedlings during first 1-2 days after grafting. Therefore, less EVTR at initial stage after grafting would be adequate for smooth joining of the scion and rootstock.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.431-433
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• 2006

The goal of this paper is improvement of vision inspection accuracy by using histogram specification operation. The histogram is composed of horizontal axis of image intensity value and vertical axis of pixel number in image. In appearance vision inspection, the histogram of reference image and input image are different because of minutely lighting distinction. The minutely lighting distinction is main reason of vision inspection error in many cases. Therefore we made an effort for elevation of vision inspection accuracy by making the identical histogram of reference image and input image. As a result of this area separation histogram specification algorithm, we could increase the exactness of vision inspection and prevent system error from physical and spirit condition of human. Also this system has been developed only using PC, CCD Camera and Visual C++ for universal workplace.