• Journal of the Korean Society of Earth Science Education
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• v.8 no.1
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• pp.35-44
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• 2015

The purpose of this paper is to identify the conceptions of middle school and high school students about visible light, Ultra violet(UV) and Infrared ray(IR). We administered questionnaire 40 people of middle school 3rd students and 43 people of high school 2nd students in Gyeonggi-do. Misconceptions about visible light, UV and Ir were observed in many students. The results of study are as follows: Firstly, Many students think that it is possible to see objects without visible light. The explanations given by students for the visiblity of objects in darkness indicates a heavy reliance on personal experiences. Secondly, we have confirmed that high school students well understand the fact that the object reflects the light. However, a significant number of students exhibited an eye-centered perspective of vision. Thirdly, students had a variety of ideas about the meaning of the term UV and IR. Analysis of questionnaire data indicates that many students believe that it is possible to see objects in the presence of UV light alone.

• Design & Manufacturing
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• v.2 no.5
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• pp.1-4
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• 2008

LCD-BLU (Liquid Crystal Display - Back Light Unit) is one of kernel parts of LCD unit and it consists of several optical sheets(such as prism, diffuser and protector sheets), LCP (Light Guide Plate), light source (CCFL or LED) and mold frame. The LGP of LCD-BLU is usually manufactured by forming numerous dots with $50-200{\mu}m$ in diameter on it by erosion method. But the surface of the erosion dots of LGP is very rough due to the characteristics of the erosion process during the mold fabrication, so that its light loss is high along with the dispersion of light into the surface. Accordingly, there is a limit in raising the luminance of LCD-BLU. Especially, the negative and positive micro-lens pattern fabricated by modified LiGA with thermal reflow process was applied to the optical design of LGP.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.492-497
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• 2008

The objective of this research is an investigation of engineering properties of weathered granite soil mixed with Phosphogypsum and recycled EPS beads as an light-weighted soil. A series of geotechnical laboratory tests including physical index test, compaction test, CBR test and direct shear test were performed for various mixing ratios. Based on the laboratory test results, it was found that the maximum dry unit weight of the light weight soil ranges $1.46{\sim}1.61g/cm^3$ and the maximum dry unit weight decreases about 11~19.3% with the increase of amount of the recycled EPS beads and the optimum moisture content increase. Since the CBR values of the light weight soil ranges 10.4~18.4%, the light weight soil mixed with Phosphogypsum and recycled EPS beads can be used as a light weight backfill material on the soft soil.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.9
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• pp.1290-1296
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• 2013

The light intensity which represents the relative amount of brightness and darkness is very important feature to discern the color hue and its relevant information. With this aim, we devise a new optical system and method to analyze the light intensity. Our suggested system including a phototransistor and white-high-brightness chip light-emitting diode intend estimate the contrast value utilizing Image Research Institute(I.R.I.) Hue & Tone samples which includes 120 color sheets arranged by the color hue and tone. As a result, we confirmed that the brightness of the color checker can be accurately estimated by a high-brightness light-emitting-diode optical system.

• Korean Journal of Human Ecology
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• v.15 no.4
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• pp.597-609
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• 2006

The purpose of the research was to compare the preference of coloration of traditional Korean dress according to tone variation of green jacket by Korean and American women college students. The results of research can be summarized as follows. Korean students preferred skirt of vivid red color and light green jacket, but American students did not like it. Korean students did not like the skirt and jacket of same color, but American students preferred it. Both Korean and American students preferred skirt and jacket of different tone. Korean students liked skirt of dull blue and jacket of light dull green, skirt of dark blue and jacket of vivid, dull green. American students liked skirt of vivid violet and jacket of vivid dull, dark green. They also liked skirt of light yellow and jacket of light green, light skirt of blue, violet and jacket of light, dull, dark green, skirt of dark blue and vivid, light, dull gueen, skirt of dark violet and jacket of dull, dark green.

• Aerospace Engineering and Technology
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• v.11 no.2
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• pp.12-18
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• 2012

In this paper, impacts on the COMS MI images during the COMS eclipse period were analyzed and the method to eliminate the contaminated area was investigated. Main effect on the meteorological images during the eclipse is a stripping effect due to a strong stray light. The quantitative analyses were conducted during the COMS In-Orbit-Test period and the impacts of the stray light on the four infrared channels of the COMS MI according to the distance with respect to the Sun were examined. Based on the typical case of the stray light influence on the infrared channel of the MI, the intensity of contamination due to the stray light was investigated for each channel using the computed COMS eclipse information. The effectiveness of removal of a contaminated area by replacing the SWIR with the combined WINDOW channels was promising.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.51.2-51.2
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• 2010

In recently, interests in the New & Renewable Energy are increasing because of exhaustion of fossil energy and limit of greenhouse gas emission all over the world. Furthermore, improvements in living standards and high-raise Buildings due to the industrial growth require a lot of sunlight in the interior space. Sunlight system gets the natural light into the indoor dark space. There are a lot of type of systems which are reflector type, duct type, optical fibers type and so on. And these systems consist of light-collection module, light-transporting module and light-emitting module. In this research, we installed optical fiber sunlight system in our head office building and tested the system's performance and efficiency. Optical fiber sunlight system is closely connected with hour of sunlight, due to the system have to chase the sun for the solar concentrating, and the system's light-collection and light- transporting efficiency is important factors in the system's performance. As a result of the test, system can be used about 5.66 hours on average in a day, and it has a about 3.21 times collection efficiency and 5.5% transmission loss.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.241-241
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• 2010

Recently high and persistent spontaneous buildup of a surface potential (SP) upon vacuum deposition of tris (8-hydroxyquinolinato) aluminum (III) ($Alq_3$), which is widely used for organic light emitting devices. The removal of the giant surface potential by visible light irradiation has also been reported. In this study, we coated $Alq_3$ on the FTO substrate and raise the capacity for absorbing sun light. The $Alq_3$ which is green light emitting diode emits light at wavelengths between 500 and 550nm. If we apply one's FTO/$Alq_3$ substrate in one's DSSC, we could get higher energy conversion efficiency because the N719 dye that we used for fabricating the DSSC emits light just at near 540nm. The energy conversion efficiency of approximately 4.8 % at the condition of irradiation of AM 1.5 (100 mW/$cm^2$) simulated sunlight, and the $J_{sc}$ is 12.0 mA/$cm^2$, $V_{oc}$ is 0.71 V, FF is 0.56, respectively.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.477-480
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• 2008

In this paper, we design the TCP-Light protocol for directly connecting a sensor network with Internet. When we are monitoring the data and controlling of the sensor node, the sensor network must be connected to Internet. But TCP in wireless networks has a number of performance problems which is high bit-error rates and a hardware constraint. Moreover, the end-to-end acknowledgment and retransmission scheme employed by TCP causes expensive retransmissions along every hop of the path between the sender and the receiver. This paper introduces The TCP-Light protocol which increases TCP performance in wireless sensor networks, decreases the number of end-to-end retransmissions and decreases memory consumption.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.05a
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• pp.106-108
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• 2004

We have investigated the photolithographic patterning method of light emitting polymer film for polymer light emitting diodes (PLED). Blue light emitting polymers based on polyfluorene, which can be cured photochemically to yield an insoluble form, have been synthesized using Ni(0) mediated Yamamoto polymerization. The relationship between patterning property and several variables such as the intensity of the exposed UV light, the concentrations of additives, has been studied by using optical microscope analysis, UV/visible spectroscopy, and photoluminescence. We have successfully fabricated PLEDs composed of the patterned emissive layer and their electroluminescence property has been also investigated. In this presentation, the detailed photolithographic patterning method and its application for polymer light emitting display will be discussed.