• Journal of Animal Science and Technology
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• 제64권5호
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• pp.985-996
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• 2022

This study investigated the effects of light intensity on growth performance, blood components, eye condition, and carcass characteristics of broiler chickens. Three hundred and fifty-two 1-day-old male chicks were assigned to one of four treatments (four repetitions per treatment, 22 birds per repetition) and reared in a floor pen for 5 weeks. From the second week, chicks were reared under four different levels of light intensity (5, 20, 35, and 50 lx) and the lighting duration was maintained at 18-hours light : 6-hours dark (18L : 6D). The feed intake and body weight were measured weekly. At 35 days of age, 12 birds per treatment were randomly selected for blood sampling, eye measurement, and carcass analysis. There were no significant differences in body weight gain, feed intake, and feed conversion ratio among treatments. Triglyceride levels in the serum were significantly higher in the 5 lx treatment, and creatinine was significantly lower in the 5 lx treatment (p < 0.05). The heterophil : lymphocyte ratios decreased significantly as light intensity increased (p < 0.05); however, other blood cell compositions were not affected by light intensity. Interleukin-6 content was significantly higher in the 5 lx treatment than in other treatments (p < 0.05), but the content of tumor necrosis factor-α was not significantly different among treatments. Serum corticosterone concentration was significantly higher at 5 lx than at 20, 35, and 50 lx (p < 0.05). The corneal diameter was the highest in 5 lx treatment (p < 0.05), and tended to increase as the light intensity decreased. Other eye parameters were not significantly different among treatments, but displayed a tendency to increase as the light intensity decreased. Carcass yield and part yields were not affected by light intensity. Meat quality parameters (pH, color, cooking loss, and water-holding capacity) did not show significant difference among the treatments. The results indicate that a light intensity of 5 lx may increase physiological stress or have a negative effect on broiler welfare, even if the performance and carcass characteristics are not affected. Therefore, a light intensity of 20 lx or above is recommended considering both the growth performance and welfare of broilers.

• 임산에너지
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• 제20권2호
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• pp.58-68
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• 2001

본 연구는 상대광도 차이에 따른 구상나무(Abies koreana Wilson) 유묘의 생장과 물질생산에 대하여 구명하고자 자연전광이 100, 50, 30, 10% 및 2%로 조절된 피음포지에서 구상나무 5년생 포트묘를 사용하여 24개월간 실시하였으며 다음과 같은 결과를 얻었다. 1. 3회의 수고생장을 측정한 결과, 가장 낮은 생장치를 기록한 2% 처리구를 제외하고 처리구 간에 큰 차이를 보이지 않았다. 2. 근원경생장은 상대광도가 낮아짐에 따라 단계적으로 감소하는 경향이 뚜렷하게 나타났다. 3. 상대적으로 낮은 광도에서 자란 유묘의 다음해 생장시작 시기가 늦어졌으며, 신엽의 갯수 및 신초의 갯수, 신초의 길이도 감소하였다. 4. 지상부와 지하부, 엽중량을 포함한 총 건물생산량은 광도가 감소할수록 점진적으로 감소하였다. 5. 구엽의 건물량에 대한 신엽의 건물량의 비율은 1년간 피음처리한 경우 0.99±0.25∼1.06±0.06으로서 100, 50, 30% 처리구에서 비슷하게 높았고, 10%와 2% 처리구에서 각각 0.60±0.04, 0.52±0.03으로서 그 비율이 상대적으로 낮았다. 2년간 피음처리한 경우에는 0.79±0.04∼1.00±0.03으로서 100, 50, 30, 10% 처리구에서 비슷하였고, 2% 처리구에서 0.29±0.03으로 매우 낮은 비율로 나타났다. 6. T/R율은 1년간 피음처리한 유묘의 경우 3.35±0.33∼4.61±0.25로서 100, 50, 30, 10% 처리구 간에 비슷하였으며, 2% 처리구에서는 7.36±0.15로서 다른 처리구에서보다 높게 나타났다. 2년간 피음처리한 유묘의 T/R율은 상대광도 2% 처리구의 2.01±0.14를 제외하고는 1.76±0.11∼3.12±0.19로서 상대광도가 감소할수록 높게 나타났다.

• 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.

• Journal of Biosystems Engineering
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• 제35권6호
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• pp.413-419
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• 2010

Plant growth was greatly affected by the spectral distribution and light intensity of artificial lighting sources. In this study, the spectral characteristics of high power sodium (HPS) lamps and metal halide (MH) lamps produced by three different manufacturers were measured. Even though the spectral distribution of HPS lamps with lamp wattage of 250 W and 400 W was very similar, but the spectral light intensity by the manufacturers was different. Difference in the spectral light intensity of MH lamps by the manufacturers was increased with the increasing lamps wattage. Light intensity at the region of blue (B), green (G), red (R) and far-red (FR) light of HPS and MH lamps was also analyzed. HPS lamps showed the light intensity in order of R, FR, B and G light. The ratio of G, B, R and FR to photosynthetic photon flux (PPF) of HPS lamps with the lamp wattage of 250 W was 3.0-3.2%, 5.5-5.9%, 17.3-19.2% and 6.5-7.8%, respectively. For MH lamps, it showed the light intensity in order of R, FR, B, and G. The ratio of B, G, R, and FR to PPF of MH lamps with 250 W was 14.0-15.5%, 22.6-27.5%, 7.5-9.5% and 2.7-4.2%, respectively. HPS and MH lamps with 400 W had a relatively smaller ratio of R and FR to PPF than those with 250 W. HPS lamps showed that the ratio of light intensity of B and FR to R was 0.15-0.28 and 0.36-0.4, respectively. For MH lamps, the ratio of light intensity of B and FR to R was 1.26-2.72 and 0.27-0.56, respectively. From these results, it was concluded that the portion of blue light of MH lamps was higher than those of HPS lamps.

• 한국광학회지
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• 제12권2호
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• pp.103-108
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• 2001

플라즈마 디스플레이 패널(plasma display panel :PDP)에서 방출되는 광의 3차원 분포를 측정하기 위한 scanned point-detecting system(SPDS)을 고안하여 제작하였으며 이 시스템을 이용하여 실제 PDP의 3차원 광 방출 특성을 측정하고 해석하였다. SPDS는 상면에 핀홀이 달려 있는 광검출기(point detector)를 위치시킴으로써 특정 지점으로부터 방출되는 광만을 검출할수 있다. 3차원 물체의 특정 지점으로부터 방출된 광은 핀홀을 지나 검출기로 모두 입사되지만 다른 지점으로부터 방출된 광은 핀홀 앞에서 미리 집속되거나 핀홀 뒤에서 집속될것이므로 이러한 광들은 핀홀에 의해 대부분 차단될 것이다. 그러므로 물체의 특정 지점으로부터 방출된 광만이 핀홀이 설치된 검출기에 의해 검출되어 진다. SPDS를 이용하여 PDP cell 내에서 측정된 3차원 광 intensity 분포로부터 cellso의 방전현상을 다음과 같이 유추해낼수 있었다. Z축 측정이 진행될수록광의 intensity는 증가하였고 ITO전극의 안쪽부분에서 검출되는 광의 intensity가 가장 컸고 Y축 scan시 나타나는 X-Z평면에서 광의 intensity가 격벽과 격벽의 중심부분에서 가장 크게 나타났다.

• 한국전기전자재료학회논문지
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• 제34권1호
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• pp.8-15
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• 2021

Micro-LEDs can be applied to various parts of a product. However, it has disadvantages compared to general LEDs in large displays such as low efficiency, intensity, and contrast ratio, among others, owing to their short history of study. The simulations were carried out using ray-tracing software to investigate the change in light intensity and light distribution according to pattern shapes on the sapphire substrate of the flip-chip micro-LED (FC μ-LED) array. Three patterns-concave square patterns, convex square patterns, and Ag coated convex patterns-which existed on the opposite side of FC μ-LEDs (115 ㎛ × 115 ㎛) array, were applied. The intensity of FC μ-LEDs on the center of the receivers depends on the pattern depth with shape. The concave square patterns having FC μ-LEDs arrays show that decreasing intensity as the patterns depth. On the contrary, the convex square patterns having FC μ-LEDs arrays shows that increasing intensity as the patterns depth. In addition, the highest intensity shows that FC μ-LEDs having Ag-coated convex patterns on the opposite side of sapphire lead to a reduction in light crosstalk owing to the Ag film.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2020년도 추계국제학술대회
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• pp.61-61
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• 2020

This experiment was carried out using artificial bed soil and LED in the plastic film house(irradiation time: 07:00-17:00/day). Seedlings(n=63 per 3.3 m²) of ginseng was planted on May 17, 2018. LED was combined with red and blue light in a 3:1 ratio and irradiated with different light intensity(40-160 µmol/m²/s). Average air temperature from April to September according to the light intensity test was 20.4℃-20.9℃. Average artificial bed soil temperature was 20.1℃-21.7℃. The test area where fluorescent lamp was irradiated tended to be somewhat lower than the LED irradiation area. The chemical properties of the test soil was as follows. pH levels was 6.6-6.7, EC levels 0.9-1.3 dS/m and OM levels 30.6-32.0%. The available P₂O₅ contents was 73.3-302.3 mg/kg. Exchangeable cations K and Ca contents were higher than the allowable ranges and mg content was high in the fluorescent lamp treatment. The photometric characteristics of LED light intensity are as follows. The greater the light intensity, the higher the PPFD(Photosynthetic Photon Flux Density) value, illuminance and solar irradiation. Fluorescent lamp treatment had high illuminance value, but PPFD and solar irradiation were lower than LED intensity 40 µmol/m²/s treatment. The photosynthetic rate increased(2.0-3.8 µmolCO²/m²/s) as the amount of light intensity increased, peaking at 120 µmol/m²/s, and then decreasing. The SPAD (chlorophyll content) value decreased as the amount of light intensity increased, and was the highest at 36.1 in fluorescent lamp treatment. Ginseng germination started on April 5 and took 14-17 days to germinate. The overall germination rate was 68.8-73.6%. The growth of aerial parts(plant height etc.) were generally excellent in the treatment of light intensity of 120-160 µmol/m²/s. The plant height was 41.9 cm, stem length was 24.1 cm, leaf length was 9.8 cm and stem diameter was 5.6 mm. The growth of underground part (root length etc.) was the best in the treatment with 120 µmol/m²/s of light intensity. Due to the root length was long(24.8 cm) and diameter of taproot was thick(18.7 mm), the fresh root weight was the heaviest at 24.8 g. There were no disease incidence such as Alternaria blight, Gray mold and Anthracnose. Disease of Damping-off caused by Rhizoctonia solani occurred 0.6-1.5% and incidence ratio of rusty root ginseng was 30.8-62.3%. It is believed that the reason for the high incidence of rusty root ginseng is that the amount of field moisture capacity of artificial bed soil is larger than the soil. Leaf discoloration rate was 13.7-32.3%.

• 한국입자에어로졸학회지
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• 제4권1호
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• pp.9-20
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• 2008

The effect of light intensity on the ozone formation and the aerosol number concentration during the photochemical reactions of ambient air was investigated in an indoor smog chamber. The smog chamber consists of a housing, 64 blacklights, and a $2.5-m^3$ reaction bag made of Teflon film. The bag was filled with the unfiltered ambient air in Seoul from January 10 to March 18, 2002. In this work, the photolysis rate of $NO_2$, $k_1$ was used as an index of light intensity. Three levels of light intensity were controlled by changing the number of blacklights turned on among 64 blacklights: $0.29min^{-1}$ (50%), $0.44min^{-1}$ (75%), $0.57min^{-1}$ (100%). The ozone concentration increased rapidly within 10 minutes after irradiation irrespective of light intensity, thereafter it increased linearly during the irradiation. The ozone production rate seems to be dependent on both the light intensity and the quality of ambient air introduced into the reaction bag. The change in aerosol number concentration also depended on both the light intensity and the ambient air quality, especially aerosol size distribution. Based on the initial ambient aerosol size distributions, the photochemical potential for aerosol formation and growth is classified into two cases. One is the case showing aerosol formation and growth processes, and the other is the case showing no apparent change in particle size distribution.

• Restorative Dentistry and Endodontics
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• 제25권2호
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• pp.299-308
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• 2000

The purpose of this in vitro study was to evaluate the microleakage of 5 curing methods in class V composite restorations which are composed of two-step light curing, pulse-delay cure, low curing-light intensity, moderate curing-light intensity and high curing-light intensity. In this study, class V cavities were prepared on buccal and lingual surfaces of 50 extracted human upper or lower molars on cementum margin. Single Bond adhesive and Z-100 shade A2 were applied for each group following the manufacture's instruction. The experimental teeth were randomly divided into 5 groups of 10 samples (20 surfaces) each. Group 1: two-step light curing; Group 2: pulse-delay cure; Group 3: low curing-light intensity; Group 4: moderate curing-light intensity; Group 5: high curing-light intensity. After 500 thermocycling between $5^{\circ}C$ and $55^{\circ}C$, the 60 teeth were placed in 2% methylene blue dye for 24 hours, then rinsed with tab water. The specimens were embedded in clear resin, then sectioned buccolingually through the center of restoration with a low speed diamond saw. The dye penetration on each of the specimen was then observed with a stereomicroscope at ${\times}20$. The composite resin/tooth interfaces were examined under Scanning Electron Microscopy. The results were statistically analyzed using the Kruskal-Wallis One Way ANOVA and Dunn's Method. The results of this study were as follows. 1. In all groups, the leakage values seen at the enamel margin were significantly lower than those seen at the dentin margin(P<0.05). 2. No group in this study showed significant differences in leakage values at both the enamel and the dentin margins(P<0.05). 3. In all groups, the gaps seen at the enamel margin were significantly lower than those seen at the dentin margin(P<0.05). 4. The gaps in this study showed significant differences and two-step light-curing and low curing-light intensity produced significant less gap than high curing-light intensity(P<0.05).

• 전기학회논문지
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• 제56권1호
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• pp.222-226
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• 2007

We suggest the fluorescence endoscope system that has light source apparatus providing selectable white or excitation light. White light source generates normal color images and is easily switched over to excitation light with the wide spectrum range from 380 nm to 580 nm. 5-ALA is deposited selectively in the abnormal tissue like cancer and causes fluorescence in the red spectrum range when excited by blue spectrum range. In addition, the others of excitation light make the color background image by reflected light to allow accurate orientation and visualization of the abnormal tissue and around. According to clinical studies, the fluorescence intensity contrast that defines the fluorescence intensity of lesion over the fluorescence intensity of around has more than 2 in tumour. Proposed system is useful and objective way in early diagnosis. Furthermore, it can be used in the biopsy for tumour classification at the highest fluorescence intensity point.