• Journal of Biosystems Engineering
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• v.38 no.4
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• pp.279-286
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• 2013

Purpose: This study was conducted to analyze the utilization efficiencies of electric energy and photosynthetically active radiation of lettuce grown under red LED, blue LED and fluorescent lamps with different photoperiods. Methods: Red LED with peak wavelength of 660 nm and blue LED with peak wavelength of 450 nm were used to analyze the effect of three levels of photoperiod (12/12 h, 16/8 h, 20/4 h) of LED illumination on light utilization efficiency of lettuce grown hydroponically in a closed plant production system (CPPS). Cool-white fluorescent lamps (FL) were used as the control. Photosynthetic photon flux, air temperature and relative humidity in CPPS were maintained at 230 ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, $22/18^{\circ}C$ (light/darkness), and 70%, respectively. Electric conductivity and pH were controlled at 1.5-1.8 $dS{\cdot}m^{-1}$ and 5.5-6.0, respectively. The light utilization efficiency based on the chemical energy converted by photosynthesis, the accumulated electric energy consumed by artificial lighting sources, and the accumulated photosynthetically active radiation illuminated from artificial lighting sources were calculated. Results: As compared to the control, we found that the accumulated electric energy consumption decreased by 75.6% for red LED and by 70.7% for blue LED. The accumulated photosynthetically active radiation illuminated from red LED and blue LED decreased by 43.8% and 33.5%, respectively, compared with the control. The electric energy utilization efficiency (EEUE) of lettuce at growth stage 2 was 1.29-2.06% for red LED, 0.76-1.53% for blue LED, and 0.25-0.41% for FL. The photosynthetically active radiation utilization efficiency (PARUE) of lettuce was 6.25-9.95% for red LED, 3.75-7.49% for blue LED, and 2.77-4.62% for FL. EEUE and PARUE significantly increased with the increasing light period. Conclusions: From these results, illumination time of 16-20 h in a day was proposed to improve the light utilization efficiency of lettuce grown in a plant factory.

• Journal of the Korean Society of Costume
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• v.64 no.7
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• pp.82-96
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• 2014

This study views the shadows cast by the light and a subject provides new interpretations rather than it simply being an additive product. Particularly in fashion photograph, light and shadows are often used as tools to convey meaning. Accordingly, this study aims to classify the utilization of the shadow created by light and deriving its expressive characteristics in fashion photograph. To achieve these research aims, literature and case studies were conducted. The results are as follows. First, the shadows were mainly focused on a subject. Secondly, shadows caused by lighting is casted directly into the inside of the main subject in a frame takes a role of omission or emphasis. Third, shadows caused by a second unseen object outside the frame are utilized with the main subject in the frame. Based on these results above, spatial third dimensionality, optical illusion and accentuation were derived as expressive characteristics of the shadow in fashion photograph. As such, in fashion photograph, shadow is an important element for photographers. The variability of the shadow makes it possible for creative changes as its amount, angle and direction can be altered by adjusting the light in accordance with the intention of the artist. Therefore, its utilization methods will be diversified hereafter. Accordingly, it is required to recognize that shadow may be recreated as an independent object in fashion photograph.

• KSBB Journal
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• v.19 no.4
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• pp.257-262
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• 2004

Recently, there is a growing interest in microalgae and the use of microalgae focused on the production of various high value metabolite used in food, pharmaceuticals and cosmetics. The key limiting factor in high density algal cultivation is the light and algal growth is defined by light intensity and light penetration depth into the culture medium. The effect of light with various light paths, S/V ratios, light intensities, and 50% duty cycle on the growth of microalgae was examined to enhance microalgal biomass productivity and photosynthetic efficiency. We confirmed that the utilization of efficient light energy was obtained from 4 cm of diameter, 57.6% of S/V ratio, 62 ${\mu}$mol/㎡/s of light intensity.

• Journal of Microbiology and Biotechnology
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• v.14 no.3
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• pp.442-449
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• 2004

Improving the light utilization efficiency of photosynthetic cells in photobioreactors (PBRs) is a major topic in algal biotechnology. Accordingly, in the current study we investigated the effect and suitability of photosynthetic pigment reduction for improving light utilization efficiency. The light-harvesting complex II (LH-II) genes of Rhodobacter sphaeroides were removed to construct a mutant strain with less pigment content. The mutant strain exhibited a slower growth rate than the wild-type under a low light intensity, while the mutant grew faster under a high light intensity. In addition, the specific absorption coefficient was lower in the mutant due to its reduced pigment content, thus it seemed that light penetrated deeper into its culture broth. However, the distance (light penetration depth) from the surface of the PBR to the compensation point did not increase, due to an increase in the compensation irradiance of the mutant strain. Experimental data showed that a reduced photosynthetic pigment content, which lessened the photoinhibition under high-intensity light, helped the volumetric productivity of photosynthetic microorganisms.

• Journal of Plant Biology
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• v.6 no.4
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• pp.1-4
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• 1963

Using conidia of Neurospora, changes in respiratory activities and the sensitivity to the ultraviolet light of the cells at different growing stages were measured by manometric methods, and the correlation between them was observed. Efficiency in the utilization of various carbon sources, such as, glucose, sucrose, maltose, starch and sodium acetate, in growth and exogenous respiration of N. crassa was also determined. Growth rate of N. crassa was decreased considerably in the medium containing sodium acetate than in the glucose medium and was almost zero in the lactose medium, whereas the utilization of sucrose, maltose and starch was ve교 high, as that of glucose. Respiratory activities of the cells veried considerably depending upon their different growing stages. Actively growing hyphae exhibited the greatest activity in exogenous glucose respiration, followed by germinating and activated conidia in decreasing order. There was no proportional relationship between the dose of ultraviolet light irradiated and its effect on the respiratory activity of the cells, though the more the dose of ultraviolet light, the more the injury. The sensitivity of the cells to ultraviolet light varied with the different respiratory activities of the cells linked to the developmental stages. In general, the more actively growing cells having high respiratory activities exhibited the more serious injury.

• Biotechnology and Bioprocess Engineering:BBE
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• v.4 no.1
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• pp.78-81
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• 1999

Light penetration depth in high-density Chlorella cultures can be successfully estimated by Beer-Lambert's law. The efficiency of light energy absorption algal cultures was so high that algal cells near the illuminating surface shade the cells deep in the culture. To exploit the potential of high-density algal cultures, this mutual shading should be eliminated or minimized. However, providing more light energy will not ease the situation and it will simply drop the overall light utilization efficiency.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2735-2744
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• 2011

Korean-Automated Guideway Transit (K-AGT) was successfully developed through Light Rail System Development Project. Since then, the domestic development rate of on-board signalling system of light rail has been improved up to 90% by Practical Utilization Project of Light Rail. After utilization project, furthermore, POSCO ICT has developed the wayside signalling system of CBTC, including wireless communication equipment. KRRI carried out the performance test of the wireless communication, interfacing and using the other CBTC equipments of KyungSan Test Line so as to see whether it conforms IEEE 802.11x, international communication standard in view of operational concept of CBTC. In this paper, we presents analysis results of roaming test while train runs.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2731-2734
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• 2011

Korean-Automated Guideway Transit (K-AGT) was successfully developed through Light Rail System Development Project. Since then, the domestic development rate of on-board signalling system of light rail has been improved up to 90% by Practical Utilization Project of Light Rail. After utilization project, furthermore, POSCO ICT has developed the wayside signalling system of CBTC, including wireless communication equipment. KRRI carried out the performance test of the wireless communication, interfacing and using the other CBTC equipments of KyungSan Test Line so as to see whether it conforms IEEE 802.11x, international communication standard in view of operational concept of CBTC. In this paper, we presents the test plan, test items, and the analysis results of maximum communication distance tests between on-board and wayside radio sets.

• Journal of the Korean Wood Science and Technology
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• v.41 no.5
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• pp.399-405
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• 2013

This study demonstrates the utilization of light microscopy and Fast Fourier Transform-Peak Finding (FPF) method for microfibril angle (MFA) measurement from unstained sections of red pine (Pinus densiflora). To obtain an image with optimal contrast and resolution for MFA measurement, effects of numerical aperture (NA) of condenser lens and color filters were investigated. About 60% of NA of the maximum condenser NA produced an image with optimal contrast, but a color filter with short wavelength range (DAPI) created images with improved resolution. Manual angle measurement and the FPF method were applied to the image with optimal contrast for MFA measurement. The experimental results from the FPF method were considered to be more repeatable and less subjective than those from the manual angle measurement.

• Korean Journal of Plant Resources
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• v.7 no.2
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• pp.137-141
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• 1994

In order to establish utilijzation of medicinal herb as vegetable by Hydroponics, the present studies were conducted to investigate the effect of temperature and light on the seed germination ofmedicinal herb. The results obtained are summaried as follows. The lower and upper temperaturelimit for herb germination was 10'c and 30'c within which the optimum was 20'C. Germinationof medicinal herb was similar in light and dark condition.