• Journal of the Optical Society of Korea
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• v.19 no.2
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• pp.159-164
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• 2015

In the injection-molded light guide plate the replication quality, i.e. the reproduction accuracy, of micro-patterns should be high and uniform over the entire surface area. However technical difficulty in meeting the necessary replication quality arises as the plate size becomes large for TV applications. We propose a simulation technique to optimize the distribution of micro-patterns on a 55-inch injection molded light guide plate considering non-ideal replication quality of micro-patterns. The luminance uniformity could be improved by more than 16% by optimizing the pattern distribution in spite of the same replication quality.

• Journal of Environmental Science International
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• v.23 no.9
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• pp.1573-1581
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• 2014

This study was conducted to examine the effect of LED light quality and supplemental LED light on growth and flowering for potted flowering plant of Kalanchoe. 1. Plant height of Kalanchoe was enhanced under Red, regardless of treatment time. 2. Root length and stem diameter of Kalanchoe were enhanced by Red+Blue. 3. The number of internodes was not influenced by LED light quality. Length of flower stalk of Kalanchoe increased under Red+Blue, but treatment time did not result in statistically significant differences. 4. Leaf area was not influenced by LED light quality in Kalanchoe. 5. The number of flower buds and open flowers was decreased by LED light treatment, but days to flowering was reduced by Red+Blue for 4 hr after sunset in Kalanchoe. 6. Chlorophyll and anthocyanin content was not significantly affected by LED light treatment, but anthocyanin content tended to increase by Blue 4 hr after sunset. 7. Fresh and dry weight did not increased by LED light treatment in Kalanchoe.

• ETRI Journal
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• v.46 no.2
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• pp.165-174
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• 2024

We propose a method to suppress the speckle noise and blur effects of the light field extracted from a hologram using a deep-learning technique. The light field can be extracted by bandpass filtering in the hologram's frequency domain. The extracted light field has reduced spatial resolution owing to the limited passband size of the bandpass filter and the blurring that occurs when the object is far from the hologram plane and also contains speckle noise caused by the random phase distribution of the three-dimensional object surface. These limitations degrade the reconstruction quality of the hologram resynthesized using the extracted light field. In the proposed method, a deep-learning model based on a generative adversarial network is designed to suppress speckle noise and blurring, resulting in improved quality of the light field extracted from the hologram. The model is trained using pairs of original two-dimensional images and their corresponding light-field data extracted from the complex field generated by the images. Validation of the proposed method is performed using light-field data extracted from holograms of objects with single and multiple depths and mesh-based computer-generated holograms.

• Journal of Nutrition and Health
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• v.39 no.6
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• pp.572-584
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• 2006

The purpose of this study was to compare the nutrient intake and diet quality of male college student according to smoking groups. Subjects were recruited and divided into three groups according to the smoking, which included non-smoker (n = 100), light-smoker (n = 78; packyear < 5), and heavy-smoker (n = 76; packyear ${\geq}$ 5). Subjects were interviewed using a general questionnaire, 24-hour recall method for dietary intake and diet quality. The average age of the subjects were 22.7 years for non-smoker, 23.5 years for light-smoker, and 23.4 years for heavy-smoker. Also the results showed that the heavy-smoker was significantly more often to drink coffee and alcohol compared with the other two groups (p<0.001, p<0.05). The mean daily energy intake was 2278.1 kcal in non-smoker, 2148.3 kcal in light-smoker, and 2144.4 kcal in heavy-smoker. The heavy-smoker consumed significantly lower intakes of vitamin C (p<0.001), calcium (p<0.01), animal calcium (p<0.01), and potassium (p<0.05) compared to the non-smoker and light-smoker. Also NAR (Nutrient Adequacy Ratio), ND (Nutrient Density), and INQ (Index of Nutritional Quality) of these nutrients in heavy-smoker were lower than the other two groups. Mean adequacy ratio (MAR) was 0.78 in non-smoker, 0.78 in light-smoker, and 0.74 in heavy smoker (p<0.05). The heavy-smoker consumed significantly lower intakes of fruits (p<0.001) compared to the non-smoker and light-smoker. The DVS (Dietary Variety Score) of heavy-smoker (26.8) was significantly lower than that 30.4 of non-smoker and 31.5 of light-smoker (p<0.01). In conclusion, heavy-smoker man have low intake status of vitamin C, calcium and potassium, and partly low diet quality. Therefore it was needed that well planed diet to replace the nutrients supplied from excluded food groups in heavy- smoker.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.4
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• pp.384-391
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• 1997

In the cultivation of Bupleurum falcatum, one of the problems to surmount is long-term germination period and unstable germination. This experiment was done to examine the effect of $GA_3$ concentration [0(water), 0.01, 0.lmM], chilling, their treatment period [2, 4, 8 days ($GA_3$) : 0, 2, 4 weeks (chilling)] and light quality (red, white, dark) given during the period as pretreatment before sowing on the seed germination of its two cultivars (cv. Jaerae, cv. Jangsu). Light treatment was given during all the periods of $GA_3$ treatment or for 0, 2, 4 days at the end of the chilling treatment. There was no difference in the mean germination rate between the levels of all the treatments except the $GA_3$ concentration meaning that water imbibition and $GA_3$ treatment had the same effect. As light quality treatment during the water imbibition was forced, the mean germination rate of Jaerae, 2 to 4 days imbibition period or red light was more increased or accelerated compared to the other levels of the same treatment, respectively. The rate of Jaerae not affected by the light quality was the greatest in the 2 days water imbibition while the rate of Jangsu was the greatest when water-imbibed for 4 days or treated by red light. No chilling before sowing showed the highest rate due to the light quality and white light forced after sowing had greater rate than the dark treatment. Although there was no difference between the rates of light quality treatment levels in the condition of no chilling before sowing and white light treatment after sowing, the rate of Jangsu was enhanced or accelerated only under illumination during 2 days water imbibition before sowing.

• Journal of information and communication convergence engineering
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• v.4 no.2
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• pp.92-96
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• 2006

Hardware for monitoring the water quality using water fleas is developed. Water flea is a frequently used biological sensor for monitoring the water quality. Water fleas quickly respond to the incoming toxic water by changing their activity when they are exposed. By measuring the activity of water fleas, the incoming toxic water is instantly detected. So far the measurement of activity of water fleas has been done with a system equipped with both a light source of LED and a light detector of photo transistor. Water flea itself is, however, sensitive to light resulting in incorrect response and the system has two inconvenient separate parts of the light source and the detector. This paper suggests a system using a CCD camera instead of a light source and a detector. The suggested system processes the image data from the CCD camera in real time without any delay. The developed system becomes a part of the remote water monitoring embedded system.

• Journal of Biosystems Engineering
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• v.31 no.5 s.118
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• pp.449-453
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• 2006

Effect of light quality on plant temperatures at joining parts of grafted watermelon seedlings was investigated using a thermal imaging system in this study. Plant temperatures at joining parts lowered than those at stem region during graft-taking. However, difference in plant temperatures at joining parts and at stem region decreased by days after graft-taking. Plant temperatures of grafted seedlings graft-taken under white, blue, red, and blue + red fluorescent lamps repeatedly fluctuated high at photoperiod and low at dark period. Considering the variation of plant temperatures at joining pa퍼5, the illumination of blue and red light as well as white light will be effective for grafting of grafted watermelon seedlings. It is recommended that air temperature around grafted seedlings should be maintained at 27 to $29^{\circ}C$ for enhancing the physiological reaction of callus and for the smooth joining of scion and rootstock.

• ALGAE
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• v.38 no.2
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• pp.141-150
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• 2023

Light quality is a common environmental factor which influences the metabolism of biochemical substances in algae and leads to the response of algal growth and development. Pyropia yezoensis is a kind of economic macroalgae that naturally grows in the intertidal zone where the light environment changes dramatically. In the present study, P. yezoensis thalli were treated under white light (control) and monochromatic lights with primary colors (blue, green, and red) for 14 days to explore their physiological response to light quality. During the first 3 days of treatment, P. yezoensis grew faster under blue light than other light qualities. In the next 11 days, it showed better adaptation to green light, with higher growth rate and photosynthetic capacity (reflected by a higher rETR_max = 61.58 and E_k = 237.78). A higher non-photochemical quenching was observed in the treatment of red light than others for 14 days. Furthermore, the response of P. yezoensis to light quality also results in the difference of photosynthetic pigment contents. The monochromatic light could reduce the synthesis of all pigments, but the reduction degree was different, which may relate to the spectral absorption characteristics of pigments. It was speculated that P. yezoensis adapted to a specific or changing light environments by regulating the synthesis of pigments to achieve the best use of light energy in photosynthesis and premium growth and metabolism.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.6
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• pp.175-182
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• 2012

Light characteristics of the monochromatic red(R), blue(B), green(G) and white(W) and the mixed LED (B-R LED) were investigated by light control a Spectrometer-MMS1 and an illuminometer. The power consumption of each LED was 1W and R LED has five wavelength bands(600nm, 640nm, 660nm, 680nm, 750nm). The light intensity of each LED was changed in a range 10~100%. As a results, the wavelength and the spectrum distribution of R LED increase with increasing light intensity but the wavelength of B, G, W LED decreases. It was found that illumination of each mononochromatic and B-R LED increases linearly with increasing light intensity. It was confirmed that the illumination intensity of R-B light has greater values than those obtained by monochromatic light at the same conditions.

• Journal of Bio-Environment Control
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• v.22 no.3
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• pp.214-219
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• 2013

This study was conducted to examine the effect of LED light quality and treatment time on the growth and flowering in potted plants of Impatiens (Impatiens hawkerihybrid). Plant height of Impatiens was enhanced under Blue light, regardless of treatment time. Root length and stem diameter of Impatiens were enhanced by Red light or Blue light. The number of internodes was not influenced by LED light quality. The number of branches of Impatiens was increased under Blue light, but treatment time did not result in statistically significant differences. Leaf area was increased by all LED lights in Impatiens. The number of flower buds and open flowers was decreased by LED light, but days to flowering were reduced by Red light in Impatiens. Chlorophyll and anthocyanin content were not significantly affected by LED light, but anthocyanin content tended to increase by Blue light for 4 h after sunset. Fresh and dry weights were enhanced by Blue light in Impatiens.