• Journal of Astronomy and Space Sciences
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• v.15 no.2
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• pp.359-371
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• 1998

We present the design specifications and the performance estimation of the FUVS (Far Ultraviolet Spectrograph) proposed for the observations of aurora, day/night airglow and astronomical objects on small satelltes in the spectral range of $900~1750AA$. The design of FUVS is carried out with the full consideration of optical characteristics of the grating and the aspheric substrate. Two independent methods, ray-tracing and the wave front aberration theory, are employed to estimate the performance of the optical design and it is verified that both procedures yield the resolution of $2~5AA$ in the entire spectral range. MDF (Minimum Detectable Flux) is also estimated using the known characteristics of the reflecting material and MCP, to study the feasibility of detection for faint emission lines from the hot interstellar plasmas. The results give that the observations from 1 day to 1 week, depending on the line intensity, can detect such faint emission lines from diffuse interstellar plasmas.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.4
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• pp.2602-2608
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• 2015

The aim of this research was microbiological hazard analysis which is required to application of HACCP(Hazard Analysis Critical Control Point) system to chili powder. A processing had been conducted in Yong-Geum Agricultural Production located in Dongnyang-myeon, Chungju-si between January 10, 2014 to June 13, 2014. A manufacturing process chart was prepared by entire level of processing. A changes of microorganism was tested by changing sterilization time in ultraviolet ray sterilization processing which can control microbiological Hazard. As a result, critical Limits is decided as ultraviolet rays lamp $20W{\times}12EA$, sterilization $63{\pm}3$ min of each. The result of the microorganism test after ultraviolet ray sterilization was safe. On the other hand, a microorganism test of manufacturing environment and workers suggested that the microbiological hazard should be reduced through systematic cleaning and disinfection accompanied by personal hygiene based on hygiene education on workers.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.290.1-290.1
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• 2016

Grapehen, a single atomic layer of graphite, has been in the spotlight and researched in vaious fields, because its fine mechanical, electrical properties, flexibility and transparence. Synthesis methods for large-area graphene such as chemical vaper deposition (CVD) and mechanical, chemical exfoliation have been reported. In particular, chemical exfoliation method receive attention due to low cost process. Chemical exfoliation method require reduction of graphene oxide in the process of exfoliation such as chemical reduction by strong reductant, thermal reduction on high temperature, and optical reduction via ultraviolet light exposure. Among these reduction methods, optical reduction is free from damage by strong reductant and high temperature. However, optical reduction is economically infeasible because the high cost of short-wavelength ultraviolet light sorce. In this paper, we make graphene-oxide and lanthanoid ion mixture aqueous solution which has highly optical absorbency in selective wevelength region. Sequentially, we synthesize reduced graphene oxide (RGO) using the solution and visible laser beam. Concretely, graphene oxide is made by modified hummer's method and mix with 1 ml each ultraviolet ray absorbent Gd3+ ion, Green laser absorbent Tb3+ ion, Red laser absorbent Eu3+ ion. After that, we revivify graphene oxide by laser exposure of 300 ~ 800 nm layser 1mW/cm2 +. We demonstrate reproducibility and repeatability of RGO through FT-IR, UV-VIS, Low temperature PL, SEM, XPS and electrical measurement.

• Journal of the Korean Wood Science and Technology
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• v.15 no.3
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• pp.24-33
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• 1987

This study was executed to investigate scanning electron microscopic characteristics of Korean Rhus lacquer coats. With the unrefined coat, distilled water, sodium hydroxide, acetic acid, ethyl alcohol, cold-check test, and accelerated weathering were performed after refining treatment. These treated lacquer coats were discussed through observation by scanning electron microscope and the obtained results were summarized as follows: 1. Compared with unrefined coat, the refined coat of Korean Rhus lacquer showed more even surface with regular distribution of dispression. 2. Korean Rhus lacquer coat heated at $120^{\circ}C$ for 3 hours revealed no observable difference irrespective of refining and unrefining. 3. Korean Rhus lacquer coat treated by distilled water, sodium hydroxide, acetic acid. ethyl alcohol, cold-check test. and ultraviolet radiation showed significant characteristics compared with untreated coat. Especially. large deformation and checkings were observed by cold-check test and ultraviolet radiation respectively. 4. The Korean Rhus lacquer coat radiated by ultraviolet ray showed 0.11 duller and 1.41 brighter than non-radiated coat through color difference calculator.

• The Research Journal of the Costume Culture
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• v.11 no.6
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• pp.967-971
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• 2003

As the concerns over health increased in 1990's, research and development on the health material were also activated. The development of UV-cut textile became the hot issue, because the damage of W irradiation due to ozone depletion has become widely known. UV-cut effect is determined by the material, the color, the organization and the density of UV-cut fibers. UV-cut effect is very different according to the fibers. Polyester is known to have a better effect. Even in the same textile material, staple fiber has more effect than filament fiber. Different colors have different offsets. Although textiles have the same color, the effects can be different according to the depth of color. PET, PET/cotton blend, nylon and cotton fabrics were ultraviolet cutting finished with padding method using several absorbers. These UV-cut effect can be improved through the processing. Safety of UV-cut textile for the body must be considered future, Until now the figure of the UV-cut effects has been emphasized. There has been no experiment on the human body, although the textiles are directly on the human body. Futhermore there os no safety standard of UV-cut textiles. Therefore every effort will be made to set the standard UV-cut processing is established. The need of UV-cut products will be known to the consumers.

• Fibers and Polymers
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• v.5 no.3
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• pp.225-229
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• 2004

The effect of UV and $^60{Co}$ gamma radiations on the physical and mechanical properties of nylon 6 mono-filaments with different draw ratios has been studied. Specimens were exposed to either up to 25 Mrad of gamma or up to 168 hrs of intense UV irradiation. The results show that nylon mono-filaments exposed to gamma rays, with much higher quantum energy than UV, undergo a larger extent of molecular chain scission. Higher irradiation dose also results in the production of insoluble, macroscopic three-dimensional cross-linked network structure. The amorphous regions with a lower density of cohesive energy (lower molecular orientation) show a higher extent of cross linking reaction whereas amorphous regions with a higher density of cohesive energy (higher orientation) show higher extent of chain scission reaction, irrespective of UV ray or gamma ray irradiation.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1404-1406
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• 1998

The outdoor polymeric insulating materials such as silicone rubber, ethylene propylene diene monomer(EPDM), ethylene vinyl acetate(EVA) and epoxy are aged by various natural environment with the long-term performance in outdoor. In this paper, the effects of UV-ray on surface of silicone rubber were investigated by using the weather-Ometer. The accelerated aging stresses were simulated by UV radiation. high temperature and humidity as well as water spray. These the aging characteristics were examined through contact angle measurements, tracking resistance test, FT-IR and SEM/EDS analysis. the experimental results showed that tracking resistance decreases with increase in the UV-ray irradiation period. But the surface of silicone rubber kept hydrophobicity. It is found that the inorganic filler such as $Al(OH)_3$ improves tracking resistance and the $TiO_2$ is very effective in preventing degradation of silicone rubber surface from UV-ray.

• Journal of the Korean Vacuum Society
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• v.12 no.4
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• pp.275-280
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• 2003

Epitaxial Gd$_2O_3:Eu^{3+}$luminescent thin films have been grout on Si(III) substrates using ionized Cluster Beam Deposition (ICBD). After the film growing, they were implanted and post annealed to change the crystal structure. The initial growth stage was monitored by using in-situ Reflection High Energy Electron Diffraction (RHEED). The formed crystal structure was identified with X-ray diffraction (XRD) technique and Fourier transform infrared (FT-R) spectroscopy. The electronic states variations were investigated by Near Edge X-ray Absorption Fine Structure (NEXAFS). Photoluminescence (PL), Cathodoluminescence (CL). and Vacuum ultraviolet (VUV) spectrum were used for examining the optical properties. We report the optical property changes depending on crystal structure and the electronic states.

• Journal of Sensor Science and Technology
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• v.14 no.5
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• pp.362-367
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• 2005

ZnO films were deposited on MgO substrates (ZnO/MgO) by ultrasonic spray pyrolysis. Substrate temperature varied from $250^{\circ}C$ to $350^{\circ}C$. The crystallographic properties and surface morphologies of the ZnO/MgO films were studied by X-ray diffraction and scanning electron microscopy. The properties of photoluminescence (PL) for the films were investigated by dependence of PL spectra on the substrate temperature and the annealing temperature. The ZnO/MgO films prepared at $350^{\circ}C$ showed the strongest Ultraviolet light emission peak at 18 K and 300 K among the films in this study. The annealing process increases the visible light emission, which is due to the increased oxygen vacancies.

• Electronics and Telecommunications Trends
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• v.13 no.5 s.53
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• pp.38-52
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• 1998

Phase-shifting masks (PSM), optical proximity correction (OPC), off-axis illumination (OAI), annular illumination (AI)의 리소그래피 분해능 향상 기법과 deep ultraviolet photoresist의 개발 및 리소그래피의 최근 기술 동향을 요약 소개한다. DUV 리소그래피의 대안으로 관심을 끌고 있는 scattering with angular limitation projection electron-beam lithography (SCALPEL), extreme ultraviolet lithography (EUVL), X-ray lithography (XRL), ion projection lithography (IPL) 등의 새로운 리소그래피 기술들의 기본 원리와 최근 기술 동향도 소개하였다. 리소그래피는 반도체 공정에 있어서 가장 중요한 부분을 차지하기 때문에 리소그래피의 최근 기술 동향을 검토해 봄으로써 국내 리소그래피 장비 산업의 기술 개발을 위한 방향 설정에 도움이 될 것으로 생각한다.