• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.49.1-49.1
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• 2014

The NISS (Near-infrared Imaging Spectrometer for Star formation history) onboard NEXTSat-1 is the near-infrared instrument onboard NEXTSat-1 which is being developed by KASI. The imaging low-resolution spectroscopic observation in the near-infrared range for nearby galaxies, low background regions, star-forming regions and so on will be performed on orbit. After the System Requirement Review, the optical design is changed from on-axis to the off-axis telescope which has a wide field of view (2 deg. ${\times}$ 2 deg.) as well as the wide wavelength range from 0.95 to $3.8{\mu}m$. The mechanical structure is considered to endure the launching condition as well as the space environment. The design of relay optics is optimized to maintain the uniform optical performance in the required wavelength range. The stray light analysis is being made to evade a light outside a field of view. The dewar is designed to operate the infrared detector at 80K stage. From the thermal analysis, we confirmed that the telescope can be cooled down to around 200K in order to reduce the large amount of thermal noise. Here, we report the current status of the NISS development.

• Korean Journal of Metals and Materials
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• v.48 no.5
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• pp.456-461
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• 2010

We investigated the In-based ohmic contacts on Nitrogen-face (N-face) n-type GaN, as well as Ga-face n-type GaN, for InGaN-based vertical Light Emitting Diodes (LEDs). For this purpose, we fabricated Circular Transfer Length Method (CTLM) patterns on the N-face n-GaN that were prepared by using a laser-lift off method, as well as on the Ga-face n-GaN that were prepared by using a dry etching method. Then, In/transparent conducting oxide (TCO) and In/TiW schemes were deposited on the CTLM in order for low resistance ohmic contacts to form. The In/TCO scheme on the Ga-face n-GaN showed high specific contact resistance, while the minimum specific contact resistance was only 3${\times}$10$^{-2}$ $\Omega$-cm$^{2}$ after annealing at 300${^{\circ}C}$, which can be attributed to the high sheet resistance of the TCO layer. In contrast, the In/TiW scheme on the Ga-face n-GaN produced low specific contact resistance of 2.1${\times}$10$^{5}$ $\Omega$-cm$^{2}$ after annealing at 500${^{\circ}C}$ for 1 min. In addition, the In/TiW scheme on the N-face n-GaN also resulted in a low specific contact resistance of 2.2${\times}$10$^{-4}$ $\Omega$-cm$^{2}$ after annealing at 300${^{\circ}C}$. These results suggest that both the Ga-face n-GaN and N-face n-GaN.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.1
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• pp.9-15
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• 1986

To establish an efficient light control method using three covering materials on tunnel shaped rice seed-bed at greening stage after seedling emergence, four rice cultivars, Nampungbyeo, Taebaegbyeo, Seonambyeo, and Seomjinbyeo were sown on 15 April and 10 May in 1983 and 1984 respectively. After seedling emergence by a simplified emerging methods the seedling boxes were moved onto tunnel shaped seed-bed which was covered with combined matrials of PE film, silverpoly sheet, and spunbonded polyester fabric. For machine transplanting of rice seedlings in cases of early season and optimum season seeding in central part of Korea, PE film tunnel with silverpoly mulched, and PE film tunnel methods with spunbonded polyester fabric mulched reduced injuries of non-parasitic seedling damping-off and a albinism as affected by it, protected rice seedlings from injuries by extremely low temperature in the night, and reduced less differences in diurnal temperature than those in the other covering methods. At late season seeding for double cropping system of paddy field in southern part of Korea, a single silver-poly or a single spunbonded polyester fabric-covered tunnel method showed good green seedlings, and prevent-ed extreme rising of diurnal temperature by light interception in the tunnel.

• Journal of IKEEE
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• v.13 no.1
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• pp.57-64
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• 2009

The optoelectrical characteristics of the ZnO nanoparticles (NPs) annealed in vacuum or oxygen condition from $200^{\circ}C$ to $600^{\circ}C$ were examined. Increased on-off ratio (or, the ratio of photocurrent to dark current) was observed when they were annealed at $300^{\circ}C$, $400^{\circ}C$ and $500^{\circ}C$ with the values enhanced about 4 orders compared to the as-prepared ZnO NPs in both annealing conditions, while the maximum efficiency was shown at the annealing temperature of $600^{\circ}C$ for the ZnO NPs annealed in vacuum with the value of 29.8 mA/W and at the temperature of $500^{\circ}C$ for those annealed in oxygen condition with the value of 40.3 mA/W. Photoresponse behavior of the ZnO NPs annealed in oxygen showed the sharp increase right after the ir exposure to the light followed by the slow decay and saturation during steady illumination, differing from the ZnO NPs annealed in vacuum which only exhibited the gradual increase. This difference occurred due to the curing effect of the oxygen vacancies. SEM images indicated no change in their morphologies with annealing, indicating the change in their internal structures by annealing, and most remarkably at $600^{\circ}C$. As for their photoluminescence(PL) spectra, the decrease of the deep-level(DL) emission was observed when they were annealed in oxygen at $400^{\circ}C$, and not at $200^{\circ}C$ and $600^{\circ}C$.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.10 no.2
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• pp.214-222
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• 2003

Purpose: This study was done to investigate sleep patterns and utilization of the charcoal eyepatch In high school students through a survey research. Method: The participants in this study were 80 students in a high school in Seoul. The period of data collection was from July 1, 2002 to 15, 2002. The research instruments used in this study were the measures of sleep and SPSSWIN 10.0 Program was used for data analysis. Result: The students went to bed after 12 p.m., but many of them easily fell asleep within 5 minutes. They woke up quite early at around 4 to 6 o'clock in the morning but remained in bed 1 hour. Satisfaction with their sleep was the response for 38.8% of the students. While 77% napped, they generally did so in the afternoon and 38.8% napped for half an hour. As for quality of sleep, 2.5% of the students could not sleep deeply, and 21.7% woke frequently during sleep. Their sleep environments were calm and comfortable, and they turned off the light when sleeping. The utilization of the charcoal eyepatch was effective for sleep, fatigue and powerlessness in high school students. Conclusion: Utilization of the charcoal eyepatch was effective for sleep in high school students and while the utilization of charcoal is recommended in life, the effect of charcoal must be testified through research.

• Journal of Fashion Business
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• v.24 no.5
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• pp.52-71
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• 2020

This study examines the color characteristics of the usage of the color pink in menswear by analyzing its usage status and method. It involves an empirical research method establishing the frame of the study through a document study centered on trend, gender neutral considerations, and the utilization of the color pink in men's fashion, by analyzing the characteristics of color and tone by extracting the pink color shown in menswear collections as well as analyzing and categorizing the fashion image and genderless characteristics. Analyzing the color and tone of the pink color shown indicate that bright, light and pale tones had higher proportions. Pink color can also be said to be utilized as a design element that gives off a younger and more vital color image in menswear. Further, the use of brighter and softer pink colors can be interpreted as reflecting modern society's demands of masculinity to change into a more sophisticated and soft image. To analyze the characteristics of the color pink utilized in gender neutral fashion, fashion images were presented as the analysis standard. An image grouping technique was used to classify pink while utilizing genderless types-fashion style. The result showed that even with the same pink color, the fashion image can vary with different methods of expression in terms of clothes and styling. The results of this study can serve as basic data for planning fashion design concepts as it analyzed pink-using fashion images and the genderless concept type.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.6 no.2
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• pp.198-210
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• 1999

This study is to investigate sleep patterns of rheumatoid arthritis patients through a survey research. The subjects for this study were 97 patients registered in Hanyang University Hospital Rheumatoid Arthritis Center, and the period of data collection was from July 15, 1998 to August 30, 1998. The research instruments used in this study were the measures of sleep, pain, and fatigue, and SPSSWIN 8.0 Program was used for data analysis. The research results are as follows ; The patients went to bed between 11 and 12 p.m., but many of them found difficulty in falling asleep within 5 minutes. They woke up quite early at around 4 to 6 o'clock in the morning and remained in bed about 1 hour. Only 39 percent of the subjects reported satisfaction with their sleep. Fifty six percent of the subjects took a nap, generally did in the afternoon and 22.7 percent of them napped for half an hour. They suffered sleep disturbance, but their sleep environments were calm and comfortable, and they turn off the light when they went to sleep. As for the quality of sleep, over 50 percent of the subjects reported not being able to sleep deeply, 30 percent of the subjects woke up frequently during sleep, 60 percent experienced frequent arousal after sleep onset. Over 90 subjects slept for 6 to 8 hours. This shows that even though they had rheumatoid arthritis, the patients remained in bed for a sufficient period of time. They also reported waking up or turning frequently during sleep. The sense of fatigue from sleep disturbance scored a relatively high 35.84 points on average against the possible score of 64 points. Behavior for sleep promotion was very active. Sleep disturbance occurred in proportion to the sense of fatigue and pain, and was negatively correlated with quality of sleep. The pain had positive correlations with the illness duration, sleep disturbance and had a negative correlation with the quality of sleep.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.12 s.354
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• pp.40-46
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• 2006

Latching optical switches and optical logic gates AND and OR are demonstrated, for the first time, by the monolithic integration of a vertical cavity lasers with depleted optical thyristor structure, which have not only a low threshold current with 0.65mA, but also a high on/off contrast ratio more than 50dB. By simple operating technique with changing a reference switching voltage, this single device operates as two logic functions, optical logic AND and OR. The thyristor laser fabricated using the oxidation process achieved a high optical output power efficiency and a high sensitivity to the optical input light.

• Journal of Astronomy and Space Sciences
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• v.31 no.1
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• pp.83-90
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• 2014

The NISS onboard NEXTSat-1 is being developed by Korea astronomy and space science institute (KASI). For the study of the cosmic star formation history, the NISS performs the imaging spectroscopic observation in the near-infrared range for nearby galaxies, low background regions, star-forming regions and so on. It is designed to cover a wide field of view ($2{\times}2$ deg) and a wide wavelength range from 0.95 to $3.8{\mu}m$ by using linear variable filters. In order to reduce the thermal noise, the telescope and the infrared sensor are cooled down to 200 K and 80 K, respectively. Evading a stray light outside the field of view and making the most use of limited space, the NISS adopts the off-axis reflective optical system. The primary and the secondary mirrors, the opto-mechanical part and the mechanical structure are designed to be made of aluminum material. It reduces the degradation of optical performance due to a thermal variation. This paper presents the study on the conceptual design of the NISS.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.391-391
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• 2016

The carrier transport is a key factor that determines the device performances of semiconductor devices such as solar cells and transistors [1]. Particularly, devices composed of in amorphous semiconductors, the transport is often restricted by carrier trapping, associated with various defects. So far, the trapping has been studied for as-grown films at room temperature; however it has not been studied during growth under plasma processing. Here, we demonstrate the detection of trapped carriers in hydrogenated amorphous silicon (a-Si:H) films during plasma processing, and discuss the carrier trapping and defect kinetics. Using an optically pump-probe technique, we detected the trapped carriers (electrons) in an a-Si:H films during growth by a hydrogen diluted silane discharge [2]. A device-grade intrinsic a-Si:H film growing on a glass substrate was illuminated with pump and probe light. The pump induced the photocurrent, whereas the pulsed probe induced an increment in the photocurrent. The photocurrent and its increment were separately measured using a lock-in technique. Because the increment in the photocurrent originates from emission of trapped carriers, and therefore the trapped carrier density was determined from this increment under the assumption of carrier generation and recombination dynamics [2]. We found that the trapped carrier density in device grade intrinsic a-Si:H was the order of 1e17 to 1e18 cm-3. It was highly dependent on the growth conditions, particularly on the growth temperature. At 473K, the trapped carrier density was minimized. Interestingly, the detected trapped carriers were homogeneously distributed in the direction of film growth, and they were decreased once the film growth was terminated by turning off the discharge.