• Journal of Ocean Engineering and Technology
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• v.34 no.6
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• pp.442-453
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• 2020

Underwater color images suffer from low visibility and color cast effects caused by light attenuation by water and floating particles. This study applied single image enhancement techniques to enhance the quality of underwater images and compared their performance with real underwater images taken in Korean waters. Dark channel prior (DCP), gradient transform, image fusion, and generative adversarial networks (GAN), such as cycleGAN and underwater GAN (UGAN), were considered for single image enhancement. Their performance was evaluated in terms of underwater image quality measure, underwater color image quality evaluation, gray-world assumption, and blur metric. The DCP saturated the underwater images to a specific greenish or bluish color tone and reduced the brightness of the background signal. The gradient transform method with two transmission maps were sensitive to the light source and highlighted the region exposed to light. Although image fusion enabled reasonable color correction, the object details were lost due to the last fusion step. CycleGAN corrected overall color tone relatively well but generated artifacts in the background. UGAN showed good visual quality and obtained the highest scores against all figures of merit (FOMs) by compensating for the colors and visibility compared to the other single enhancement methods.

• Journal of the Korean Society of Clothing and Textiles
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• v.42 no.5
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• pp.871-883
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• 2018

This study tests consumer responses to online product recommendation service offered by a website. A product recommendation service refers to a filtering system that predicts and shows items that consumers would like to purchase based on their searches or pre-purchase information. The survey is conducted on 300 people in an age group between 20 and 40 years in a panel of an online survey firm. Data are analyzed using confirmatory factor analysis and structural equation modeling by AMOS 20.0. The results show that personalization quality does not have a significant effect on trust, but relationship quality and technology quality have a positive effect on trust. Three types of quality of recommendation service also have a positive effect on commitment. Trust and commitment are factors that increase service usage intentions. In addition, this study reveals the moderating effect of light users vs heavy users based on online shopping time. Light users show a negative effect of personalization quality on trust, indicating that they are likely to be uncomfortable to the service using personal information, compared to heavy users. This study also finds that trust vs commitment is an important factor increasing service usage intentions for heavy users vs light users.

• Journal of the Semiconductor & Display Technology
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• v.23 no.2
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• pp.100-106
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• 2024

To generate the plasma required in dry cleaning processes, the plasma chamber must be supplied with a high-quality AC voltage with a voltage of more than 1 kV and a frequency of 400 kHz. In the existing research, many methods to supply high power have been studied, but how to improve the quality of the power for high-quality plasma has been relatively little studied. In this paper, we propose a study to improve the quality of RF power circuit for high-quality plasma generation in dry cleaning method. Existing methods in the environment of full-bridge-based RF power circuits must perform PWM duty control in the light load region. This causes distortions in the waveform, resulting in poor power quality, which directly leads to poor plasma quality. To solve these problems, a half-bridge switching method is proposed and the improvement in waveform quality is verified. To verify the feasibility of the design and control algorithm proposed in this paper, an RF power circuit prototype is fabricated and the proposed design and control method is verified through simulation and actual experiments under dummy load.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.1117-1118
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• 2008

The LightScribe Technology is for printing images on the label side of recordable media using CD laser diode. By implementing Optimum Labeling Power Calibration for LightScribe, Labeling Quality can be improved. This paper proposes a new laser power calibration method using RFSUM signal. This function is implemented based on GH22LP20 of LG Electronics.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.314-316
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• 2005

Light flicker is a notorious phenomenon influencing light quality. The flicker of the light flux outputs from the light sources perceived by human eyes depends upon the lamp brightness fluctuations for projector display. This paper describes a ballast ignition control system, which makes the lamp strike frequency phase lock the blanking time period to minimize the flicker effect

• Journal of Environmental Science International
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• v.4 no.4
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• pp.21-21
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• 1995

The effects of plant hormones (NAA, $GA_3$ and BA) and light qualities (white, red, green and blue light) on the changes of reducing sugar contents and invertase isozyme activities in leaves of maize (Zea mars L.) and mung bean (Phseolw radiatus L.) seedlings were investigated. NAA accelerated the increase of reducing sugar contents and invertase isozyme activities, on the contrary, $GA_3$ had little effect in the accumulation of reducing sugar and in the increase of enzyme activities from the leaves of maize and mung bean seedlings. On the other hand, BA accelerated an increase in the activities of the invertase isozyme from the leaves of mung bean seedlings whereas it had little effect in the increase of the enzyme activities from those of maize seedlings. The accumulation of reducing sugar in leaves of both seedlings was promoted by red light irradiation compared to white light irradiation, while the activities of the enzyme were little affected by various light Qualities. In the simultaneous applications of plant hormone and light quality, NAA with white light was very effective in the increase of reducing sugar contents and the enzyme activities from the leaves of mung bean seedlings, whereas NAA application with blue light showed a prominent enhancement in the reducing sugar contents and the enzyme activities from those of maize seedlings. These results suggest that plant hormone, particularly NAA, may be a more important factor than various light Qualities in the stimulation of invertase activity.

• Journal of Environmental Science International
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• v.4 no.4
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• pp.323-333
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• 1995

The effects of plant hormones (NAA, $GA_3$ and BA) and light qualities (white, red, green and blue light) on the changes of reducing sugar contents and invertase isozyme activities in leaves of maize (Zea mars L.) and mung bean (Phseolw radiatus L.) seedlings were investigated. NAA accelerated the increase of reducing sugar contents and invertase isozyme activities, on the contrary, $GA_3$ had little effect in the accumulation of reducing sugar and in the increase of enzyme activities from the leaves of maize and mung bean seedlings. On the other hand, BA accelerated an increase in the activities of the invertase isozyme from the leaves of mung bean seedlings whereas it had little effect in the increase of the enzyme activities from those of maize seedlings. The accumulation of reducing sugar in leaves of both seedlings was promoted by red light irradiation compared to white light irradiation, while the activities of the enzyme were little affected by various light Qualities. In the simultaneous applications of plant hormone and light quality, NAA with white light was very effective in the increase of reducing sugar contents and the enzyme activities from the leaves of mung bean seedlings, whereas NAA application with blue light showed a prominent enhancement in the reducing sugar contents and the enzyme activities from those of maize seedlings. These results suggest that plant hormone, particularly NAA, may be a more important factor than various light Qualities in the stimulation of invertase activity.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.9
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• pp.424-433
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• 2014

The purpose of this study is to evaluate the effectiveness in the lighting performance of mixed type light-shelf, by comparing and analyzing the internal light-shelf, external light-shelf, and mixed-type light-shelf. The performance of light-shelf was evaluated according to the angle of light-shelf at summer solstice, winter solstice, vernal equinox, and autumn equinox. The comparative analysis between the internal light-shelf, external light-shelf, and mixed-type light-shelf was carried out using the performance evaluation and analysis method. The result of performance evaluation is shown as follows. The mixed type light-shelf showed the highest lighting performance all at summer solstice, winter solstice, vernal equinox, and autumn equinox, followed by the external light-shelf and the internal light-shelf in the same order. The mixed type light-shelf was the most favorable for bringing daylight to indoors by adjusting the angle of light-shelf, and it also showed the highest lighting performance in terms of uniformity ratio of illumination which indicates the quality of light.

• Agricultural and Biosystems Engineering
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• v.1 no.2
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• pp.81-87
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• 2000

Quality characteristics of tomatoes irradiated with light (red light of far-red light followed two days later with a red light treatment), treated with ethylene, and stored in darkness were evaluated by subjective sensory and objective physical and chemical evaluations. Overall and individual liking evaluations and sensory evaluations were made by an untrained panel of eighteen people. A rankin gof treatments for consumer (panelist) acceptability was also conducted by the panel. Physical and chemical evaluations included surface color measurement (L*, a*, and b*), mechanical puncturing (firmness), soluble solids content (SSC), titratable acidity(TA), and tomato juice pH. Sensory data showed that outside color, inside color, and flavor of tomatoes treated with red light (R) and far-red light/red light (FR/R) were scored significantly higher than those of tomatoes treated with ethylene and those kept in darkness. The L* values for tomatoes treated with R and FR/R were lower (more darkening) than those for tomatoes treated with ethylene and those stored in darkness. Tomatoes treated with FR/R had the highest A* values, followed by those irradiated with R, treated with ethylene, and kept in darkness, respectively. Sensory values for firmness were similar for tomatoes treated with R, FR/R, and ethylene. Treatments had no significantly different effects on sweetness and acidity. There were no significantly different effects between treatments for pH, SSC, TA, and SSC/TA. From observations made during the study, it was suggested that R irradiation stimulated red color development in tomatoes after it had been delayed by FR irradiation. Consumer acceptability for tomatoes with either R or FR/R treatment was significantly higher than that for tomatoes treated with ethylene or stored in darkness. panelists' overall liking scores correlated well with all sensory variables except acidity, and also correlated highly with inside color, flavor, and sweetness (P<0.001). Overall liking versus flavor had the most pronounced relationship (r=0.78, P<0.001).

• Journal of Bio-Environment Control
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• v.10 no.1
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• pp.55-60
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• 2001

To investigate the effect of red light (R) and far-red light(FR) on controlling the growth of tomato transplants, height, length of 1st internode, and stem diameter of plant were measured every 12 days during 24 days of light treatment. At the end of experiment, fresh and dry weights of roots and shoots were measured. Generally, it was shown that the height of plant was suppressed by the treatment of FR. However, the effect of light-treatment time (10 or 20 min) on plant height was not significant. Stem diameter of the plant treated with R was greater than that of the plant treated with FR or the control. Dry weight ratio of shoot to root of the plant treated with R was smaller that of the plant treated with FR. R was more effective than the control, which was more effective than FR, in making the transplant compact.