• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.10a
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• pp.427-428
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• 2013

The Lighthouses and light beacons are representative structures of Aids to Navigation(AtoN) facilities. Incheon had been the region where they were constructed actively in early moden era. This study is targeting the lighthouse and light beacon which are managed by Regional Maritime Affairs. They will be organized by the research from field investigation. And conservation and management method for long-term preservation on the objects that has cultural and historical values will be suggested through this study.

• Journal of Aquaculture
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• v.7 no.1
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• pp.1-7
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• 1994

The effects of temperature and light intensity on the photosynthesis were investigated in fronds and cultivated filaments of Porphyra pseudolinearis Ueda. The optimum temperatures for total photosynthesis of fronds and filaments were $25\~30^{\circ}C\;and\;20^{\circ}C$, respectively. The photosynthetic rates of fronds and filaments based on light intensity were shown in a typical light saturation curve where the rates were constant over the light intensity of approximately 10,000 lux. The compensation points were 2,100 lux in fronds and 900 lux in filaments. The photosynthetic rate of filaments was 5 to 10 times greater than that of fronds. This would be very advantageous for filaments to conduct photosynthesis in the condition of dim light.

• Journal of Biosystems Engineering
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• v.35 no.2
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• pp.124-131
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• 2010

Chlorophyll fluorescence has been researched for assessing fruit post-harvest quality and condition. The objective of this preliminary research was to investigate the potential of fluorescence spectroscopy for measuring apple fruit quality. Ultraviolet (UV) and blue light was used as an excitation source for inducing fluorescence in apples. Fluorescence spectra were measured from 'Golden Delicious' (GD) and 'Red Delicious' (RD) apples using a visible/near-infrared spectrometer after one, three, and five minutes of continuous UV/blue light illumination. Standard destructive tests were performed to measure fruit firmness, skin and flesh color, soluble solids and acid content from the apples. Calibration models for each of the three illumination time periods were developed to predict fruit quality indexes. The results showed that fluorescence emission decreased steadily during the first three minutes of UV/blue light illumination and was stable within five minutes. The differences were minimal in the model prediction results based on fluorescence data at one, three or five minutes of illumination. Overall, better predictions were obtained for apple skin chroma and hue and flesh hue with values for the correlation coefficient of validation between 0.80 and 0.90 for both GD and RD. Relatively poor predictions were obtained for fruit firmness, soluble solids content, titrational acid, and flesh chroma. This research has demonstrated that fluorescence spectroscopy is potentially useful for assessing selected quality attributes of apple fruit and further research is needed to improve fluorescence measurements so that better predictions of fruit quality can be achieved.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.115-115
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• 2011

Biodiesel (BD) was made from animal-fats reacting with methanol and potassium hydroxide in the laboratory. The biodiesel made in the laboratory was sent to K-petro, the government agency, to inspect the quality of animal-fats biodiesel, of which generally the quality was acceptable for heating oil for agricultural hot air heater. Kinematic viscosity and calorific values of the biodiesels were measured. BD20(K), kerosene based biodiesel, showed 18cSt at $-20^{\circ}C$. It seems that BD100 can not be suitable for heating fuel under some temperature. As BD content increased calorific value decreased, up to 40,000J/g for 100% BD, while light oil calorific value was 45,567J/g, showing difference of 5,567J/g, about 12% difference. Several different fuels, BD20, BD50, BD100 and light oil, were prepared and tested for fuel combustion qualities for agricultural hot air heater and their combustion performances were compared and analyzed. Flame dimensions of biodiesels and light oil were almost same shape at the same combustion condition in the burner of the hot air heater. Generally $CO_2$ amounts of BDs are greater than light oil. But,the differences are so small that it is hard to tell there was significant difference existed between the BDs combustion and light oil.

• Textile Coloration and Finishing
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• v.27 no.4
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• pp.288-300
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• 2015

This study was executed to substitute Carbon-arc method, which is a method currently used for testing light-fastness of military textile products, with Xenon arc method. Specimens used in the study were classified according to the fabric material and color of military textile products and were composed of 11 items of 42 kinds with different colors. Light-fatness test was done by comparing the result of Carbon-arc(KS K 0700) and Xenon arc(KS K ISO 105-B02) method. In Xenon arc method, blue wool reference materials of 1~8 was used, and exposure condition preferred in American continent and light exposure method 3 were applied. After testing with both methods, grade of light-fastness, color difference, reflectance and color were examined. Even though there was a slight difference among 42 specimens used in the test, results exceeded the quality standard both in Carbon-arc-lamp and Xenon arc-lamp. Therefore, it was confirmed that applying KS K ISO 105-B02 together in the KS K 0700-regulated Ministry of National Defense standard and purchase order would also fit.

• Journal of the Korean Society of Safety
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• v.22 no.6
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• pp.13-19
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• 2007

Diesel car's smoke measurement equipment and method were investigated based on the exhaust gas regulations. Reflection photo method and light extinction method for measuring smoke were compared under conditions of both no load mode and Lug-down 3 mode. Free acceleration mode at no load condition was used for regular inspection of diesel car, and Lug-down 3 mode was used for fine inspection of the diesel car. A correlation between no load mode and Lug-down 3 mode was investigated in this research. The smoke measured with reflection photo method was 1.5${\sim}$2 times higher than that of light extinction method The correlation coefficient between reflection photo method and light extinction method for measuring smoke was 0.83, which shows comparatively high correlation between the two methods for measuring smoke in diesel engines.

• Journal of Sensor Science and Technology
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• v.31 no.1
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• pp.31-35
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• 2022

The efficacy improvement of the light emitting diode (LED) was studied for the realization of small-size, low power consumption, and highly sensitive bio-sensor instrument. The performance of the LED with Mg delta-doping at the interface of AlGaN/GaN super-lattice in p type cladding layer was simulated. The device with Mg delta-doping showed improved current, radiative recombination rate, electroluminescence, and light output power compared to the conventional LED structure. Under the bias condition of 5 V, the improved device exhibited 20.8% increase in the light output power. This is attributed to the increment of hole concentration from stable ionization of Mg in p type cladding layer. This result is expected to be used for the miniaturization, power saving, and sensitivity improvement of the bio-sensor system.

• Journal of Korea Foresty Energy
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• v.20 no.2
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• pp.58-68
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• 2001

This study was carried out to investigate the growth and biomass production of Abies koreana seedlings under different relative light intensity. The 5-year-old potted seedlings were grown for 24 months under different light intensity of 100%, 50%, 30%, 10% and 2% of the natural full light intensity. The results were as follows: 1. Height growth was similar in the seedlings under different light intensities except in 2% of the full sun light intensity, having shown the lowest height growth. 2. Root collar diameter growth was reduced gradually by decreasing of the relative light intensity. 3. The seedlings which were grown under relatively low light intensity showed the later starting date of the stem growth in the next spring and showed the smaller number of new needles, and the smarter number and the shorter length of new shoot of the seedlings. 4. Total dry mass including the dry mass of leaves, shoot and root was reduced by decreasing of the relative light intensity. 5. In case of the seedling grown in one year shading condition, the ratio of the dry mass of current-year needles and stem to that of the above one-year-old needles and stem was ranged from 0.99$\pm$0.25 to 1.06$\pm$0.06 and was not significally different among the seedlings grown under 100%, 50% and 30% of the relative light intensity. And the radio was ranged from 0.60$\pm$0.04 to 0.52$\pm$0.03 in the seedlings grown under 10% and 2% of the relative light intensity, respectively. In case of the seedling grown in two years shading, the ratio of the dry mass of current-year needles and stem to that of the above one-year-old needles and stem was ranged from 0.79$\pm$0.04 to 1.00$\pm$0.03 and was not significally different among the seedlings grown under 100, 50, 30% and 10% of the relative light intensity. And the ratio was 0.29$\pm$0.03 in the seedlings grown under 2% of the relative light intensity, respectively. 6. T/R ratio of the seedlings grown in one year shading condition was ranged from 3.35$\pm$0.33 to 4.61$\pm$0.25 and was not significantly different among the relative light intensities of 100%, 50%, 30% and 10%. The seedlings grown under 2% of relative light intensity showed the highest T/R ratio of 7.36$\pm$0.15. In case of the two years shadings the T/R ratio was ranged from 1.76$\pm$0.11 to 3.12$\pm$0.19 and increased as relative light intensity decreased except 2.01$\pm$0.14 in 2% of relative light intensity.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.8
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• pp.1289-1293
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• 1990

In this paper, the oscillation condition for the linear phase-conjugate oscillator which consists of one photorefractive crystal, two conventional mirrors, and two pump waves applied externally has been analyzed. In the result, it has been shown that the oscillation condition of this oscillator can be easily controlled by adjusting the various parameters such as the intensity ratio, polarization states, and light path difference of two pump waves, etc.

• Proceedings of the IEEK Conference
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• 2003.07e
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• pp.2028-2031
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• 2003

This paper proposes a face identification algorithm, robust on lighting condition and complex background. The proposed method estimates facial area under bad light condition by expanding face color boundaries and then finds a lip using the templates for lips. Then the eyes are found using their topological relationship with the long and short axes of lip area. The experimental results have shown that the proposed algorithm is robust on lighting conditions and complex background.