• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.45 no.3
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• pp.135-143
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• 2009

To study the behavioral reaction of common squid Todarodes pacificus, to different colors of LED light, individual distribution in the dark condition without LED light stimuli, individual distribution when four colors of light stimuli were at the sections of end and middle of water tank and the changes of gathering rates as the elapse of illuminating time were examined. When it was dark, the distribution of the fish in each section of the tank was U-shape regardless of the investigating time intervals, which means that Todarodes pacificus gathered at the both ends of the tank. The individual distribution when light stimuli were at the one end of the tank showed the tendency of gathering at the illuminated section and decreasing at the opposite section. There were 448 of them at the end of the tank when the light was blue, 352 when white, 302 when green and 132 when red. Thus the fish liked blue light the most, followed by white light. The variations of gathering rate at the both ends of tank as illuminating time elapsed showed the tendency of increasing at the light section (A section), however, it showed the tendency of decreasing at the darkest section (F section). The individual distribution showed the tendency of letter $\wedge$ of gathering at the center and decreasing at the both ends mostly when the light stimuli were at the middle section of tank. The gathering rates at the lighting section were 80.4% when red, 76.4% when white, 69.6% when green and 56.7% when blue. The fishes showed the affinity for the red light mostly, followed by the white light source. The red light and blue light showed the opposite when the light stimuli were at the one end of water tank. The variations of gathering rates as the elapse of time at the lighted section showed the tendency of gradual increasing in the four light sources. The color of light source showing the highest gathering rate within 25-30 minutes of light stimuli was the white, followed by the red.

• Fire Science and Engineering
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• v.24 no.5
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• pp.136-141
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• 2010

The purpose of this study is to examine the structure and heat generation mechanism of low voltage switches used to turn on or off the power supply to an indoor lighting system and investigate how the fixtures and movable contacts of the switches are damaged depending on the types of energy sources in order to secure the judgment base for expected PL disputes. Based on the Korean Standard (KS) testing method for incombustibility, this study applied a general flame to the switch. In addition, current was supplied to the switch using the PCITS (Primary Current Injection Test System). The ambient temperature and humidity were maintained at $22{\pm}2^{\circ}C$ and 40~60% respectively while performing the test. It is thought that the switch generated heat due to a defective connection of the wire and clip, insulation deterioration and defective contact of the movable contact, etc. The surface of the switch damaged by the general flame was uniformly carbonized. When the flame source was removed, the fire on the switch was extinguished naturally. From the result obtained by disassembling the switch carbonized by the general flame, it could be seen that fixtures and movable contacts remained in comparatively good shape but the enclosure, clip support, movable contact, indicating lamp, etc. showed carbonization and discoloration. In the case of the switch damaged by overcurrent, the clip connecting the wires, clip support, etc. showed almost no trace of damage, but the fixtures, movable contact, indicating lamp, etc. were severely carbonized. That is, the sections with high contact resistance were intensively damaged and showed a damage pattern indicating that carbonization progressed from the inside to the outside. Therefore, it is possible to judge the initial energy source by analyzing the characteristics of the carbonization pattern and the metal fixtures of damaged switches.

• Design & Manufacturing
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• v.14 no.1
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• pp.8-14
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• 2020

In general, auto parts production assembly line is assembled and produced by automatic mounting by an automated robot. In such a production site, quality problems such as misalignment of parts (doors, trunks, roofs, etc.) to be assembled with the vehicle body or collision between assembly robots and components are often caused. In order to solve such a problem, the quality of parts is manually inspected by using mechanical jig devices outside the automated production line. Automotive inspection technology is the most commonly used field of vision, which includes surface inspection such as mounting hole spacing and defect detection, body panel dents and bends. It is used for guiding, providing location information to the robot controller to adjust the robot's path to improve process productivity and manufacturing flexibility. The most difficult weighing and measuring technology is to calibrate the surface analysis and position and characteristics between parts by storing images of the part to be measured that enters the camera's field of view mounted on the side or top of the part. The problem of the machine vision device applied to the automobile production line is that the lighting conditions inside the factory are severely changed due to various weather changes such as morning-evening, rainy days and sunny days through the exterior window of the assembly production plant. In addition, since the material of the vehicle body parts is a steel sheet, the reflection of light is very severe, which causes a problem in that the quality of the captured image is greatly changed even with a small light change. In this study, the distance between the car body and the door part and the door are acquired by the measuring device combining the laser slit light source and the LED pattern light source. The result is transferred to the joint robot for assembling parts at the optimum position between parts, and the assembly is done at the optimal position by changing the angle and step.

• Food Science and Preservation
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• v.20 no.1
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• pp.81-87
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• 2013

Agri-food garlic has been recognized as healthful because of its antibacterial, anticancer and antioxidant effects. As such, its consumption is steadily increasing. This study was conducted to amplify the healthful ingredient of garlic, allicin, using light irradiation. The following conclusions were drawn from the investigation of peeled garlic under various conditions like fluorescent lighting, color (green, yellow, blue and red) and ultraviolet light (UV-A, UV-B and UV-C). The allicin content increased most with the 15-second $0.129W/m^2$ (40 W) UV-B treatment of the garlic at a 700 mm distance from the light source. At the treatment of the garlic with 126 lx (40W) red light for 24 hours at a 700 mm distance from the light source, its allicin content increased from $15.15{\pm}0.25mg/g$ to $15.15{\pm}0.34mg/g$, for a 10-percent amplification effect. Therefore, it is believed that the healthfulness of garlic can be amplified through irradiation processing of its healthful ingredient, allicin, and the development of its processing unit.

• Journal of Bio-Environment Control
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• v.31 no.1
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• pp.14-21
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• 2022

Uniform scions and rootstocks should be produced to ensure grafting success. Light quality is an important environmental factor that regulates seedling growth. The effects of warm- and cool-white light emitting diode (LED) ratios on seedling growth were investigated. Scions and rootstocks of cucumber, tomato, and watermelon were grown in a closed transplant production system using LED as the sole lighting source. The LED treatments were W1C0 (only warm-white), W1C1 (warm-white: cool-white = 1:1), W3C1 (warm-white: cool-white = 3:1), and W5C2 (warm-white: cool-white = 5:2). The seedlings grown in W1C1 had the shortest hypocotyls, and the seedlings grown in W1C0 had the longest hypocotyls among the three tested vegetables. The hypocotyls of watermelon scions, watermelon rootstocks, and tomato rootstocks were shortest in W1C1, followed by those in W3C1, W5C2, and W1C0, but there was no significant difference between W3C1 and W5C2, which remained the same as the ratio of cool-white LEDs increased. In addition, tomato scions had the first and second longest hypocotyls in W1C0 and W3C1, respectively, and the shortest hypocotyls in W5C2 and W1C1, along with W5C2 and W1C1, although the difference was not significant. The stem diameter was highest in W1C0 except for tomato seedlings and rootstocks of watermelon. The shoot fresh weight of scions and rootstocks of cucumber and watermelon and the root fresh weight of cucumber scions were lowest in W1C1. These results indicated that different ratios of LED lighting sources had a strong effect on the hypocotyl elongation of seedlings.

• Journal of the Korean Vacuum Society
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• v.16 no.3
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• pp.172-180
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• 2007

A new diagnostics of plasma electron temperature and plasma density is introduced with the observation of the light emission along the tube of external electrode fluorescent lamps. With two different methods operating an external electrode fluorescent lamp of outer diameter 4.0 mm and length 860 mm for the back-light source of 37-inch LCD-TVs, the lighting modes and the plasma properties are investigated. In the center balance operation, the light-emission propagates simultaneously from both sides of the high voltage electrodes to the center of the lamp, while in conventional operation the light-emission propagates from the one end of a high voltage to the other ground electrode. In the operation value of luminance $10,000{\sim}15,000cd/m^2$, the electron plasma thermal energy $(kT_e)$ is about $1.3{\sim}2.7eV$ with the electron density $(n_e)$ is about $(1.6{\sim}3.6){\times}10^{16}m^{-3}$.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.10 no.6
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• pp.62-72
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• 1996

In this paper, ozonizer using U-type lamp(Olamp) has been designed and manufactured, which can perform a role of lighting source and ozonizer by using photo and chemical methods. The discharge, spectrum, illuminance, ozone concentration, ozone generation, ozone yield and sterilization characteristics of Olamp have been studied. The important conclusions obtained from this paper can be summa'||'&'||'not;rized as follows. As a result of spectrum characteristics for Olamp, ultraviolet ray of a short wave'||'&'||'not;lengths and a visible ray are radiated. The illuminance of Olamp was found to be useful for "color distinctive and intermittent works in the dark working spaces" in accordance with KS A 3011. The ozone concentration of gaseous phase is inversely proportional to quality of supplied gas. Also, ozone conce tration and generation of gaseous phase are rised more commercial oxygen gas than those trial air gas for constant quality of supplied gas. Ozone generation and ozone yield of gaseous phase are proportion'||'&'||'not;al to ozone concentration of gaseous phase. The characteristics of liquid ozone concentration at distilled water are proportional to circulating velocity of fermentation chamber and ozone concentration of gas'||'&'||'not;eous phase. As a result, the sterilization characteristics of Escherichia coli have been obtained more than 97[ % J.

• International Journal of Highway Engineering
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• v.13 no.4
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• pp.231-238
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• 2011

Variable message signs(VMS) in use are being displaying with the LED device as the luminous source, and it is a recent trend to be changed from the Lamp type to the Surface-Mount Devices(SMD) type. The LED device leads to get VMS display brightly and clearly, leading to have visibility and legibility better than the existing VMS. However, the lights which display off the road, the unnecessary energy, might have negative effect on ecosystem. This study developed the way of getting the lights be displayed only to drivers without the unnecessary energy and estimated the energy efficiency of the development by the optical testing. As a result, this study showed that the energy consumption of the developed display device appeared to decrease by about 36.1% compared to the existing device. Also the upward and downward angle of the lights changed from an angle of $24^{\circ}C$ to $0^{\circ}C$and from an angle of $-24^{\circ}C$ to $-11^{\circ}C$, respectively. Therefore, it anticipates that the developed device would benefit highway safety due to an improvement in visibility and legibility compared to the existing VMS and the energy consumption would be less lower than the existing VMS.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.1
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• pp.84-92
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• 2020

To supply a stable amount of standard material to detect paralytic shellfish toxin (PST), we examined possible increases in toxic content in Alexandrium catenella and A. pacificum using a light emitting diode (LED), which is one of the most eco-friendly and economical lighting method. When comparing the growth rates of organisms and wavelengths of light used, the half saturation constants (Ks) of red wavelength were higher than those of other wavelengths. In contrast, the Ks of blue wavelength were lower than those of other wavelengths. Moreover, when comparing the toxic contents and wavelengths of light used, red wavelength produced approximately 8 times more toxic content in A. catenella and approximately 3.2 times more toxic content in A. pacificum than other wavelengths. Thus, the toxic content present in the organism might be closely related to the Ks of light. The optimum light source to be used to ensure economically ef ective and productive growth in an Alexandrium culture system (photo-bioreactor) would likely consist of a two-phase culture, wherein a blue LED is used during the lag and exponential phases to increase growth rates, followed by the use of a red LED during late exponential and stationary phases to achieve increased PST yields.

• The Korean Journal of Ecology
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• v.17 no.1
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• pp.1-9
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• 1994

This study focuses on forest fires attributed to cigarette light, the main source of wild fires, by examining the characteristics of the fire types. It aims to present useful data for preventive measures. Statistics show that the average length of cigarette butts left after smoking is 30mm excluding filter for domestic cigarette smokers. Also the average thickness of litter layer in forests is 58.2mm throughout the nation. The value varies according to how often leaves were trodden by hikers : the accumulation amount of Mt. Sunchi. which is relatively protected from human disturbances, is 29.6% more than that of Mt. Kye-Ryong National Park. Aged trees such as Pznus rzgidu, Quercus acutissima and Larix leptolepis have relatively large inflammable contents, 2.43kg in 15 year-old stand and 2.55kg in 10 year-old stand. This study found out the following fact with regard to the start of lighting and the out-break of fire. Fire breaks out within five minutes in the sample(C), in which Zoysza gaponica and Populus X tomentiglandulosu has been tramped when the sample has 2~6 percent of moisture contents. Coniferous trees such as Pinus rigida and Larzx leptolepis do not burn easily while leaving charcoal. In contrast, deciduous trees with Zoysia japonzca and Populus X tomentiglandulosu are quick to catch fire. As a result of the experiments, it is proved that cigarette light is a very dangerous cause of wild fire especially for dry grass like Zoysia gaponica.