• 한국전기전자재료학회논문지
• /
• 제18권6호
• /
• pp.582-586
• /
• 2005

We have grown GaN layers with in-situ SiN mask by metal organic chemical vapor deposition (MOCVD) and study the physical properties of the GaN layer. We have also investigate the effect of the SiN mask on its optical property. By inserting a SiN mask, (102) the full width at half maximum (FWHM) decreased from 480 arcsec to 409 arcsec and threading dislocation (TD) density decreased from $3.21\times10^9\;cm^{-2}\;to\;9.7\times10^8\;cm^{-2}$. The PL intensity of GaN with SiN mask improved 2 times to that without SiN mask. We have thus shown that the SiN mask improved significantly the physical and optical properties of the GaN layer.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2002년도 춘계학술대회논문집
• /
• pp.460-465
• /
• 2002

The nonlinear vibration of the CRT shadow mask is analyzed in consideration of the V-shaped tension distribution and the effect of wire impact damping. The reduced order FEM model of the shadow mask is obtained from dynamic condensation for the mass and stiffness matrices. Damping wire is modeled using the lumped parameter method to effectively describe its contact interactions with the shadow mask. The nonlinear contact-impact model is composed of spring and damper elements, of which parameters are determined from the Hertzian contact theory and the restitution coefficient, respectively. The analysis model of the shadow mask with damping wires is experimentally verified through impact tests of shadow masks performed in a vacuum chamber. Using the validated analysis model of the shadow mask with damping wires, the‘design of experiments’technique is applied to search fur the optimal damping wire configuration so that the vibration attenuation of the shadow mask is maximized.

• 한국융합학회논문지
• /
• 제10권8호
• /
• pp.291-298
• /
• 2019

본 연구의 목적은 뷰티관심도가 마스크팩 사용 만족도 및 재구매에 미치는 영향을 분석하는 것에 있다. 본 연구는 마스크팩을 사용해본 소비자를 대상으로 설문지 305부의 자료를 SPSS. v21 통계 패키지 프로그램을 활용하여 분석하였다. 분석결과 뷰티 관심도 하위요인은 마스크팩 사용만족도 하위요인에 통계적으로 유의미한 정(+)의 영향을 미치는 것으로 나타났고, 마스크팩 사용만족도 하위요인은 재구매 의도에 유의미한 정(+)의 영향을 미치는 것으로 나타났다. 본 연구의 결과 소비자의 뷰티 관심도가 높을수록 마스크팩 사용만족도가 중요하며 그에 따라 재구매 의도가 높아지는 것으로 나타남을 알 수 있었다. 본 연구를 통해 향후 마스크팩 판매기업이 소비자들의 니즈를 파악하고 마케팅 요소로 활용한다면 성공적인 마케팅 효과를 기대할 수 있을 것이다.

• 한국응용과학기술학회지
• /
• 제33권1호
• /
• pp.30-40
• /
• 2016

본 연구는 2단계 발효된 달팽이 추출물을 5% 사용한 시트 마스크 팩 (2F-SEM)을 개발하였다. 이에 대한 피부미용학적 연구를 수행하기 위하여 순면 100%의 시트를 사용하여 얼굴모양으로 커팅하여 사용하였다. 플라세보 마스크 팩 (placebo mask pack; PM)과 일반 용매추출에 의한 달팽이 추출물을 사용한 마스크 팩 (Gene-SEM)에 대하여 피부 개선효과를 측정한 결과를 보고한다. 첫째; 2F-SEM의 보습효과는 PM 보다 11%, Gene-SEM는 PM 보다 4.7%가 상승되었다. 둘째; 2차 발효달팽이 추출물이 함유된 마스크 팩의 탄력도는 PM 보다 13.8%, Gene-SEM PM 보다 6.7% 이상 개선하는 효과를 보였다. 셋째; 2F-SEM의 피부 거칠기는 PM 보다 6.80%, Gene-SEM는 PM 보다 2.3%가 개선되었다. 넷째; 2F-SEM의 멜라닌감소효과는 PM 보다 15.0%, Gene-SEM는 PM 보다 8.7%이상 개선되었다. 다섯째; 2F-SEM의 잔주름개선효과는 PM보다 8.0%정도 우수하였다. Gene-SEM는 PM 보다 5.1%이상 개선되었다. 여섯째; 2차 발효 물을 이용한 2F-SEM의 관능 평가는 부드러움(softness), 보습 감(moisture), 주름개선효과(fine wrinkle improvement)에서 유의 차 있는 사용감촉을 보였다.

• 제어로봇시스템학회논문지
• /
• 제14권4호
• /
• pp.348-352
• /
• 2008

Deformation of the shadow mask is one of the problems encountered during the deposition of organic materials for manufacturing large size organic light emitting diode (OLED). The larger the glass substrate, the larger the shadow mask becomes. As the size of the shadow mask increases, its deformation becomes more severe, thereby making it difficult to deposit organic materials in a precise pattern on a substrate. In this paper, a new method for reducing drooping of the shadow mask for large size OLED vapor depositions is proposed. The proposed shadow mask with cross stripe wires has higher stiffness than the pure shadow mask, which results in reducing drooping of the shadow mask. A commercial FEM program, ANSYS, is used for the evaluation of the proposed shadow mask. The analysis showed that the shadow mask with cross stripe wires have an effect on reducing drooping about 18.6% or more.

• Transactions on Electrical and Electronic Materials
• /
• 제5권6호
• /
• pp.215-218
• /
• 2004

This paper presents a three-dimensional numerical simulation for thermal oxidation process. A new elasto-viscoplastic model for robust numerical oxidation simulation is proposed. The three-dimensional effects of oxidation process such as mask lifting effect and corner effects are analyzed. In nano-scale process, the oxidant diffusion is punched through to the other side of the mask. The mask is lifted so the thickness of oxide region is greatly enhanced. The compressive pressure during the oxidation is largest in the mask corner of the island structure. This is because the masked area near the corner is surrounded by an area larger than the others in the island structure. This stress induces the retardation of the oxide growth, especially at the masked corner in the island structure.

• Physical Therapy Rehabilitation Science
• /
• 제10권4호
• /
• pp.438-443
• /
• 2021

Objective: The purpose of this study was to determine the effect of the difference in mask filters on the respiration rate of healthy people. Design: A randomized cross-over design. Methods: A total of 15 subjects were selected for this study (n=15). After filling out the Physical Activity Readiness Questionnaire, the selected participants abstained from caffeinated beverages and meals 30 minutes before and sat in a chair 10 minutes before stabilizing their breathing. Afterwards, the lung function test was performed 3 times for each mask, and the maximum value was used. The provided masks were Mask Free, Dental Mask, KF80, and KF94. Exhalation was measured for 6 seconds for each mask, and breathing was stabilized by repeating inhalation and exhalation until the next time. Results: In this study, the difference in respiratory function according to the mask type was statistically significant except for FEV1 and FVC (p<0.05). As a result of post-hoc analysis, FVC, FEV1, PEF, and FEF values were significantly lower than those of the control group not wearing a mask (p<0.05). When wearing KF94, FVC, FEV1, PEF25-25%, and FEF were significantly lower than when wearing a dental mask (p<0.05). When wearing a KF80 mask, it was significantly lower in FVC and FEV1 than when wearing a dental mask (p<0.05). In FEV1/FVC, the difference by mask type was not statistically significant (p<0.05), but it was lower than the spirometry standard of COPD patients (FEV1/FVC<0.7). Conclusions: As Now that wearing a mask is essential, it has been confirmed that the mask affects the respiratory rate.Therefore, in the case of healthy adults, it is recommended to rest after wearing a mask if attention deficit or headache occurs. People with low breathing capacity are recommended to have low-intensity activities and frequent rest periods after wearing a mask.

• 한국소음진동공학회논문집
• /
• 제12권9호
• /
• pp.731-737
• /
• 2002

Nonlinear vibration of the CRT shadow mask with impact damping wires is analyzed in consideration of the mask tension distribution and the effect of wire impact damping. A reduced order FEM model of the shadow mask is obtained from dynamic condensation of the mass and stiffness matrices, and damping wire is modeled using the lumped parameter method to effectively describe its contact interactions with the shadow mask. The nonlinear contact-impact model is composed of spring and damper elements, of which parameters are determined from the Hertzian contact theory and the restitution coefficient, respectively. The analysis model of the shadow mask with damping wires is experimentally verified through impact tests of shadow masks performed in a vacuum chamber.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
• /
• pp.4-7
• /
• 1997

When we use Hadamard transform spectrometers (HTS), we can increase signal to noise ratio(SNR) by multiplexing which is done by masks. But if the mask has a single defective element, output-SNR decreases. In this paper the effect of a single defective element on the output-SNR is investigated. And a method of compensating for the defective mask element is presented.

• 한국방사선학회논문지
• /
• 제14권3호
• /
• pp.313-318
• /
• 2020

라돈은 불활성기체로서 단원자분자이기 때문에 입자 하나의 크기가 원자 하나의 크기를 나타내며 이는 대략 반경 1~100 nm를 가지고 있다는 것을 의미한다. 따라서 마스크가 차단하는 일반적인 미세먼지, 초 미세먼지의 크기보다 작은 반경을 가지지만 일정 이상의 라돈의 흡입을 차단할 수 있다면 평소 실내착용을 통해 라돈의 흡입을 통한 피폭을 줄일 수 있을 것으로 사료된다. 이에 따라 일상생활에서 착용하는 마스크의 라돈 차단 효과를 알아보고자 한다. 각각의 마스크 별 라돈 감소율을 보면 면 마스크가 33.45%, 의료용 마스크가 33.50%, KF80 마스크가 35.12%, KF94 마스크가 37.72% 순으로 감소하였다. 면, 의료용 마스크가 KF 마스크보다 라돈 차단 효과가 다소 떨어지지만 그 차이는 크지 않아 마스크의 착용만으로도 공기 중 라돈의 유입을 일정 수준 차단할 수 있음을 알 수 있었다.