• Journal of the Korean Crystal Growth and Crystal Technology
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• v.30 no.6
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• pp.251-257
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• 2020

In order to quickly and clearly recognize characters or images through display glass, glare of the glass must be suppressed. In this study, we tried to reduce glare by analyzing changes in glass surface shape and optical properties through etching process. The etching process was performed as a function of concentrations of the etching solutions, BOE and HF. During the etching process, a compound containing F ion was generated on the surface of the glass, forming an irregular pattern in the form of a projection, and thus various optical properties of the glass were changed; reflectance of 2.5~4.6 %, haze of 4.5~6.6 %, transmittance of 77~92 %, and gloss of 82~107 GU. As a result, optimum etching condition was obtained to minimize the loss of other optical properties while suppressing glare of the glass.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.6
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• pp.1313-1320
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• 2023

This paper presents the development of a smart mirror that allows control of its display through glove gestures and integrates voice recognition functionality. The hardware configuration of the smart mirror consists of an LCD monitor combined with an acrylic panel, onto which a semi-mirror film with a reflectance of 37% and transmittance of 36% is attached, enabling it to function as both a mirror and a display. The proposed smart mirror eliminates the need for users to physically touch the mirror or operate a keyboard, as it implements gesture control through glove gesture sensors. Additionally, it incorporates voice recognition capabilities and integrates Google Assistant to display results on the screen corresponding to voice commands issued by the user.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.38 no.1
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• pp.34-42
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• 2001

The new periodic array structure or frequency selective surface with polarizers characteristic is proposed. The present structure is constructed with two sheets or FSS material, spaced about one-eight wavelength apart, the dipole element orientations of the two sheets being almost perpendicular to each other. The methods of the spectral domain immittance and MoM are used to analyze electromagnetic scattering from this periodic array structure. To confirm the validity of the polrizer's functions or the new periodic array structure, frequency selective surfaces are fabricated, calculated values for the frequency response of the reflection and transmission loss are compared with measured values. Good correspondence has been observed between them. Good axial ratio has been also observed to be achieved in the proposed structure.

• Journal of the Korea Convergence Society
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• v.9 no.4
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• pp.93-98
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• 2018

This study was wanted to confirm ability for UV blocking according to its material. The lenses materials were Acryl, CR-39, NK-55, and MR-8. It was grouped: Group A consisting of anti-scratch hard coated lenses and anti-refractive multi coated lenses, Group B added UV blocking coating on the group A, and Group C consisting of only UV blocking lenses. The results measured UV transmittance, On the UV-A wavelength, Group A showed the UV transmittance of 7.726%, 0.043%, 0.007%, and 0.007% respectively. Group B showed 0.038%, 0.037%, 0.007%, and 0.007%, respectively. The UV-blocking performance of CR-39 has been greatly improved. Group C has shown the best UV blocking function; only 0.005% and 0.004% of UV transmittances.(1.60 and 1.67 index of refraction respectively). For the low power of lenses and sunglasses, the CR-39 lens is the most used. Therefore, to UV blocking from the lens, new materials or UV absorbers or UV coating technology and development of Converged Technologies are required.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.5
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• pp.672-679
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• 2014

To improve sensing capability of infrared, heat-resistance and mechanical properties, the $SiO_2$ and $TiO_2$ anti-reflective layers were coated on sapphire substrate by MOCVD. The standard wavelength was 4,600nm, and the thickness of anti-reflective layers were 379 and 758nm in case of ${\lambda}/4$ and ${\lambda}/2$ of incident angle($65^{\circ}$), respectively. The $SiO_2$ and $TiO_2$ anti-reflective layers were coated 12.6 and 9.7nm/min of deposition rates by increasing oxygen pressure to set the ideal refractive index of 1.283. In case of $SiO_2({\lambda}/2)$ coating, the transmittance increased from 55.0 to 62.7%. The transmittance of $TiO_2({\lambda}/2)$ anti-reflective layer also increased from 55.0 to 64.8%. The flexural strength of $SiO_2({\lambda}/2)$ and $TiO_2({\lambda}/2)$ layer coated sapphire increased from 337.8 to 362.9 and 371.8MPa, respectively. The flexural strength at $500^{\circ}C$ of these materials also increased respectively to 304.5, 358.2MPa from 265.9MPa. From these results, we confirmed these materials can be used as transmission window of infrared light.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.165-165
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• 2010

GaInZnO는 투명 비정질 산화물 반도체로서 태양전지, 평판 액정 디스플레이, 잡음방지 코팅, 터치 디스플레이 패널, 히터, 광학 코팅 등 여러 응용에 쓰인다. 이 논문에서는 투명전자소자로 관심을 모으고 있는 GaInZnO의 전자적 그리고 전기적 특성을 측정하였다. GaInZnO 박막은 $SiO_2$ (100)/Si 기판위에 RF 마그네트론 스퍼터링 증착법으로 $Ga_2O_3:In_2O_3:ZnO$의 조성이 2:2:1로 된 타겟을 가지고 박막을 성장시켰다. 성장한 후에 RTP를 이용하여 30분간 열처리 하였다. GaInZnO의 전자적 특성을 나타내는 띠틈 및 실리콘 기판과의 원자가 띠 오프셋 값을 측정하였으며, 이 값들을 통해 GaInZnO박막과 실리콘 기판과의 띠 정렬도 수행하였다. 띠틈은 반사 전자 에너지 손실 분광법(REELS)을 이용하여 측정하였고, 원자가 띠 오프셋은 광전자 분광법(XPS)을 이용하여 측정하였다. 열처리 온도가 $400^{\circ}C$까지는 띠틈의 변화 및 XPS 결합에너지의 변화가 없는 것으로 보아 열적안정성이 우수함을 알 수 있다. 반면 $450^{\circ}C$에서의 띠틈이 감소하는 것으로 보아 $450^{\circ}C$에서는 열적안정성이 깨지는 것을 알 수 있다. GaInZnO 박막을 채널 층으로 하고 전극은 알루미늄(Al)으로 된 TFT를 제작하여 전기적 특성을 조사하였다. TFT 특성 결과 이동도가 약, subthreshold swing(S.S)이 약 1.5 V/decade, 점멸비가 약 $10^7$으로 측정되었다. 유리 위에 증착시킨 GaInZnO 박막의 투과율을 측정해본 결과 모든 시료가 가시광선 영역에서 80%이상의 투과율을 갖는 것으로 보아 투명전극소자로 응용이 가능하다는 것을 알 수 있었다.

• Journal of the Korean Vacuum Society
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• v.15 no.1
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• pp.24-30
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• 2006

Integrated cavity output spectroscopy(ICOS) is a simple, non-intrusive absorption measurement technique that can detect and quantify trace-level gas species. The spectral absorbance of a gas is quantified from the integrated optical output of the modulated high-finesse cavity containing the sample which is irradiated by a wavelength-swept laser source. We constructed an experimental setup by using a tunable single mode external cavity diode laser operating at the wavelength near 765 nm and a Fabry-Perot cavity with length modulation achieved by a piezoelectric transducer where one of the cavity mirrors sat on. In the experiment performed on minute oxygen gas at the wave-length near 764.5nm, we demonstrated the minimum detectable absorption of $8.45\times10^{-8}cm^{-1}$.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.6
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• pp.64-71
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• 2004

The object of this study is to design the Radar Absorbing Structures (RAS) having sandwich structures in the X-band ($8.2{\sim}12.4GHz$) frequencies. Glass fabric/epoxy composites containing conductive carbon blacks and carbon fabric/epoxy composites were used for the face sheets. Polyurethane(PU) foams containing multi-walled carbon nanotube (MWNT) were used for the core. Their permittivities in the X-band were measured using the transmission line technique. The reflection loss characteristics for multi-layered sandwich structures were calculated using the theory of transmission and reflection in a multi-layered medium. Three kinds of specimens were fabricated and their reflection losses in the X-band were measured using the free space technique. Experimental results were in good agreements with simulated ones in 10dB absorbing bandwidth.

• Korean Journal of Plant Resources
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• v.8 no.3
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• pp.325-334
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• 1995

The early senescence mutant induced from Gihobyeo by $\gamma-ray$ irradiation was determined. The mutated gene expression was identified with comparing the characteristic of original cultivar. The mutant had so similar the morphological characteristics to original cultivar that it couldn't be distinguished until senescence occurred at about 20 days after heading. Suddenly yellow leaves were observed within a few days due to great decreases in total chlorophyll and various carotenoid contents. Transmission electron microscopy showed the formation of starch granules, distortion of fine structure of leaf cell organelles, especially grana structures, and the decrease in grain filled after senescence occurred. But banding patterns of total proteins and isozymes have not show any differences, The early senescence mutant will be very useful for study material not only on physiological and biochemical properties of plant senescence but also on gene expression regulating senescence which gives great influence on yield potential and its stability.

• Journal of Industrial Convergence
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• v.20 no.10
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• pp.33-38
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• 2022

In this paper, a simple method of forming a solution-based carbon nanotube (CNT) for use as a conductive material for electronic devices was studied. The CNT thin film coating was performed on the glass by applying the spin coating method and the argon atmospheric pressure plasma process. In order to observe changes in electrical and physical properties according to the number of coatings, samples formed in the same manner from times 1 to 5 were prepared, and surface shape, reflectance, transmittance, absorbance, and sheet resistance were measured for each sample. As the number of coatings increased, the transmittance decreased, and the reflectance and absorptivity increased in the entire measurement wavelength range. Also, as the wavelength decreases, the transmittance decreases, and the reflectance and absorption increase. In the case of electrical properties, it was confirmed that the conductivity was significantly improved when the second coating was applied. In conclusion, in order to replace CNT with a transparent electrode, it is necessary to consider the number of coatings in consideration of reflectivity and electrical conductivity together, and it can be seen that 2 times is optimal.