• Journal of Animal Science and Technology
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• 제64권3호
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• pp.432-442
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• 2022

The purpose of this study was to analyse the effects of light colour on rabbit reproductive performance and the expression of key follicular development genes. Rabbits (n = 1,068, 5 months old, 3.6-4.4 kg live body weight) were divided randomly into four groups, housed individually in wire mesh cages and exposed to red, green, blue, and white light-emitting diode (LED) light (control). The lighting schedule was 16 L : 8 D-15 d / 150 lx / 6:00 am-22:00 pm (3 d preartificial insemination to 12 d postartificial insemination). Red light and white light affected the conception rate and kindling rate and increased the total litter size at birth (p < 0.05). The effects of red light on litter size at weaning, litter weight at weaning, and individual weight at weaning increased compared with the green and blue groups. The effects of red light on live litter size at birth were increased compared with those in the blue group (p < 0.05). Compared to white light, green and blue light reduced the number of secondary follicles (p < 0.05). Compared to red light, green and blue light reduced the number of tertiary follicles (p < 0.05). Compared with white light, red LED light resulted in greater ovarian follicle stimulating hormone receptor and luteinizing hormone receptor mRNA expression (p < 0.05). Compared with green and blue LED light, red LED light resulted in greater B-cell lymphom-2 mRNA expression (p < 0.05). Compared with green LED light, red LED light inhibited FOXO1 mRNA expression in rabbit ovaries (p < 0.05). Red light can affect the reproductive performance of female rabbits and the expression of key genes for follicular development.

• 한국멀티미디어학회논문지
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• 제20권11호
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• pp.1729-1740
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• 2017

This paper describes a vision-based method that effectively recognize a traffic light. The method consists of two steps of traffic light detection and discrimination. Many related studies have used color information to detect traffic light, but color information is not robust to the varying illumination environment. This paper proposes a new method of traffic light detection based on intensity and saturation. When a traffic light is turned on, the light region usually shows values with high saturation and high intensity. However, when the light region is oversaturated, the region shows values of low saturation and high intensity. So this study proposes a method to be able to detect a traffic light under these conditions. After detecting a traffic light, it estimates the size of the body region including the traffic light and extracts the body region. The body region is compared with five models which represent specific traffic signals, then the region is discriminated as one of the five models or rejected as none of them. Experimental results show the performance of traffic light detection reporting the precision of 97.2%, the recall of 95.8%, and correct recognition rate of 94.3%. These results shows that the proposed method is effective.

• 수면정신생리
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• 제15권1호
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• pp.12-16
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• 2008

Light therapy (also called light treatment or phototherapy) involves scheduled exposure to bright artificial light. Evidence-based treatments for sleep disorders especially for circadian rhythm sleep disorders include light therapy and pharmacotherapy. In clinical practice, many of patients with sleep problems tend to impair circadian rhythmicity. Considering that light is the most potent entraining agent of circadian rhythm, careful use of light therapy can be recommended for patients with several kinds of sleep disorders. I briefly review the possible therapeutic mechanisms and clinical applications of light therapy, focusing on circadian sleep disorders.

• 대한치과교정학회지
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• 제34권5호
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• pp.429-438
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• 2004

본 연구는 Plasma arc light를 이용하여 금속 브라켓의 부착시 광조사 방향, 중합시간 그리고 경화시간이 전단결합강도에 미치는 영향을 평가하기 위해서 시행되었다. 240개의 발거된 소구츠를 16군으로 나눈 후. 광중합기(Plasma arc light와 Halogen light), 중합시간(Plasma arc light 2. 4. 6초와 Halogen light 20초). 그리고 광조사 방향(Vertical 방향과 Oblique 방향)을 다르게 하여 브라켓을 부착하였다. 광증합 접착제는 Transbond XT를 이용하였으며 브라켓 부착 후 5분과 24시간 후에 만능물성시험기를 이용하여 전단결합강도를 측정하였다. 결과는 다음과 같다. 광중합기의 종류와 중합시간에 관계없이 Vertical군과 Oblique군간의 전단결합강도는 유의한 차이가 없었다.(p>0.05) Plasma arc light를 이용하여 2초 동안 광중합한 군들의 전단결합강도는 다른 중합시간의 군들보다 현저히 낮았다(P<0.05). 부착 5분 후의 전단결합강도는 24시간 후보다 현저히 낮았다(P<005), ARI 점수는 군들 간에 통계적으로 유의한 차이가 없었다. 이상의 결과는 plasma arc light를 사용한 금속 브라켓의 부착시 광조사 방향은 전단결합강도에 영향을 끼치지 않으며. Halogen light와 유사한 결합강도를 얻기 위해서는 4초 이상의 중합시간이 필요함을 시사한다.

• 한국환경과학회지
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• 제22권11호
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• pp.1499-1508
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• 2013

In the results of investigating the role of LED light quality in enhancing the ornamental value of indoor foliage plants, amber and red light increased plant height, leaf width, and leaf stalk, and the consequent tree shape decreased the ornamental value. The chlorophyll content increased significantly under white light and compound light. With regard to the effect of plant leaf color on ornamental value, the value of lightness was markedly enhanced by red light. As to the functionality of plants according to photosynthetic activity, plants such as Dieffenbachia, Clusia, and Dracaena were found favorable to those staying indoors for a longtime from morning to evening. Spathiphyllum, and Ficus were found to be recommendable for indoor spaces used actively during afternoon because their photosynthesis was activated in the afternoon. With regard to power consumption according to light quality, white light consumed 119 W/hour, around 45% lower than that of fluorescent lamps, so it is considered the optimal artificial light quality that can enhance energy efficiency. Red light consumed 72 W/hour, only 33% of that of fluorescent lamps, but it was not considered the optimal light quality because plant growth was poor under the light quality. White light and compound light were found to be the ideal light sources for improving the functionality and ornamental value of indoor plants and reducing the cost of maintenance, but because compound light hinders people from recognizing the original color of plants and makes their eyes easily tired, white light was considered the optimal light satisfying all of the ornamental value, economic efficiency and functionality resulting from plant growth.

• 수면정신생리
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• 제5권2호
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• pp.170-176
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• 1998

Nowadays light therapy is accepted practice in the treatment for Seasonal Affective Disorder. The author reviewed the practical aspects of light therapy, latest treatment research on optimal parameters of light therapy and the mechanisms of action of light therapy. Therapeutic efficacy of light therapy using light visors & dawn simulators has been suggested but further studies are needed to clarify the efficacy. The treatment most strongly supported by research studies is light therapy using a light box to administer bright white light (2500 lux for 2 hours or 10000 lux for 30 minutes). Although some patients may be selective responders to morning light exposure, the optimal timing of light exposure still remains controversial. In practice, generally the duration of exposure can be increased or decreased as necessary and also the timing of exposure can be splitted (e.g. AM/PM usage) if optimal response is obtained. For most, a positive response of light therapy is usually noted within $4{\sim}5\;days$ and optimal response is obtained within 2 weeks. Generally the relapse of symptom occurs within days of discontinuation of light therapy, so to prevent relapse, light therapy should be continued throughout the winter season for typical seasonal affective disorder. Side effects of light therapy appear to be mild and well tolerated. Several theories for the mechanisms of action of light therapy at the basis of seasonal affective disorder had been suggested but remain still controversial. Further studies on the optimal parameters and the mechanisms of light therapy help us to better understand and treat not only seasonal affective disorders but also chronobiological disorders and nonseasonal affective disorders.

• 자동차안전학회지
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• 제11권4호
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• pp.16-21
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• 2019

In recent years, most automobile manufacturers have been using slim light source images to imprint their own brand image and identity. A light guide type lamp is widely used for making these kinds of a slim light source image. A light guide lamp means using a light emitting diode light source at one end of a long cylindrical pipe. The light from the light emitting diode source moves through the pipe by total reflection principle. Moving light is sent forward by various optic structures which is applied in the cylindrical pipe. However, the light guide lamp has a problem that the image of the light differs depending on the viewing direction, and in some cases there is dark section. It means light guide has low quality about lighting image. In this paper, trying to improve the fundamental problems of the light guide mentioned above by using various triz methods. Through functional modeling, estimating the factors affecting the light in the light guide lamp and make various ideas to improve the lighting image using the chain effect cause analysis, function oriented search scientific database techniques. Using these kinds of various TRIZ methods, finally find solutions that can improve the brightness and lighting uniformity of the light guide lamp. The ideas obtained in this paper were applied to actual vehicle development, and several patents achievements were obtained. In conclusion, it is proved that TRIZ method is useful for making ideas in actual automobile industrial field and is also a useful method for acquiring patent.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.1956-1960
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• 1991

This paper describes the measured results upon monochromatic light, compound light, and light emanated from light emitting diodes by a simplified wavemeter with a semiconductor color sensor. Since a single unit element of a semiconductor color sensor with two PN junction photodiodes has been developed, the author has fabricated the simplified wave detector by using the element. The simplified wive detector has been measured results upon monochromatic light, compound light, and light emanated from light emitting diodes. Since luminescent color of each diode locates in luminosity region, comparison of measured values of PD-150 and PD-151 resulted no remarkable difference in averaged wave length. As for monochromatic light, PD-151 showed very cross value to the color filter peak value rather than PD-150. As for compound light, PD-150 has shown such influence of long wave length light which reaches to near infrared ray with respect to PD-151.

• KIEAE Journal
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• 제10권2호
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• pp.71-78
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• 2010

Spill light by street lighting is a kind of light pollution creating cozy night atmosphere, interfere visual private and cause insomnia at night. This study was to survey light trespass of the windows in residential buildings. According to outdoor lighting control guidance in Seoul, three different areas were selected to investigate the trespass light to windows. The results were as follows: 37% of the buildings of 386 buildings were influenced by street lighting, and 47% of windows were occurred light trespass. Therefore, the street lighting affected light trespass at night in survey area. The main reasons of light trespass were luminaire type, luminaire pole height, and street width. For protecting the light trespass to windows, it is necessary to non-cutoff fixture to full cutoff fixture by the street width.

• KIEAE Journal
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• 제2권1호
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• pp.49-54
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• 2002

Solar daylighting system provides free and comfort lighting, but its cost has been key issue due to difficult design and control of the heavy light collecting system. One of the solutions for the heavy design issues would be using a light framed film such fresnel and prism lens. Prism light guide luminaires have for some time been used to distribute light when it is desirable to have remote light sources. These systems are helpful when it is desirable to have fewer light sources, and/or to position light sources in places where lamp maintenance is easier, or electrical hazard is reduced. This proposed prototype system consists of light collector, light transformer and light pipe.