• 한국항공운항학회지
• /
• 제26권3호
• /
• pp.55-65
• /
• 2018

The SBD systems have made it possible that all boarding procedures are completed by passengers. With the SBD, air tickets can be issued and baggage can be consigned without the help of airline officers. This way, the SBD can improve the passenger circulation speed as well as decrease the time for passengers to wait for check-in, which is connected to the reduction of airlines' operaitonal costs. However, given that the SBD is a new technology, it has potentials to be used as a tool for air terrorism. This study purposes to determine methods to enhance the security and operation of SBD systems. With the aim, this paper investigated the existing literature on SBDs, self-check-in, airport security, air terrorism, risk management, aviation accidents, and information security. In order to compile real-time information about the SBD operations, twelve airports in North America, Europe, and Asia were analyzed based on existing studies on international SBD trends.

• Design & Manufacturing
• /
• 제9권3호
• /
• pp.9-13
• /
• 2015

Plastic material has been applied to many automobile parts with the automotive lightweighting trend. In this study, a passenger air bag(PAB) housing which is produced by steel material in the present were molded using a plastics material. Before design and making of a mold for the PAB housing molding, it was carried out injection molding analysis. By analyzing the deformation results, the correction dimension for mold designing was determined. The design and manufacturing the mold applied the correction dimension were conducted. It was performed actual injection molding. The warpage value of the PAB housing was similar to the warpage of the injection molding analysis.

• 한국자동차공학회논문집
• /
• 제9권4호
• /
• pp.193-203
• /
• 2001

The Monte Carlo method was used to evaluate the reliability of crash discrimination algorithms. Through the Fast Fourier Transformation, crash pulses obtained during frontal crash tests of a mini van and a sports utility vehicle were transformed to signals in the frequency domain, and the signals were divided into basic signals and changeable signals. The changeable signals were modified through random generation, and they were combined with the basic signals. Then, the combined signals were transferred back to the time domain. In this way numerous crash pulses could be generated. For the generated pulses, crash discrimination algorithms were evaluated by examining whether they did not result in air bag deployment for the pulses requiring no air bag deployment and whether they resulted in time-to-fires faster than required time-to-fires for the pulses requiring air bag deployment. The crash discrimination algorithm in which the absolute value of the deceleration change multiplied by the velocity change or the summation of the absolute value of the deceleration change was used as a metric was Proven to be highly reliable.

• 한국대기환경학회지
• /
• 제19권4호
• /
• pp.437-449
• /
• 2003

A multi-functional indoor smog chamber was designed and evaluated to investigate photochemical or water vapor reaction mechanisms of air pollutants. Various smog chamber experiments could be conducted using ambient air or purified air in this smog chamber. The smog chamber consisted of a housing, a Teflon bag, blacklights, injection ports, sampling ports, and utility facilities. The characteristics of light source, the wall losses of air pollutants, and the quality of purified air were experimentally investigated. The maximum NO$_2$ photolysis rate was 1.10 min$^{-1}$ . In a 2.5-m$^3$ Teflon bag, the wall losses of ambient $O_3$, NO, and NO$_2$ were 1.2~2.4$\times$10$^{-3}$ min$^{-1}$ , 0.7~2.0$\times$10$^{-3}$ min$^{-1}$ , and 0.4~2.0$\times$10$^{-3}$ min$^{-1}$ , respectively. The wall loss of ambient particles ranging 0.05 to 0.2 ${\mu}{\textrm}{m}$ was 1.8~5.4$\times$10$^{-3}$ min$^{-1}$ , which was slightly higher than those of ambient gaseous species. The purified air supply system provided high quality of air with NO$_{x}$ < 1 ppb, and total hydrocarbons < 5 ppb.b.

• 한국대기환경학회지
• /
• 제31권1호
• /
• pp.54-62
• /
• 2015

Small scale paint overspray booths are being operated nationwidely, for repair of passenger car body parts. paint aerosols are emitted from the paint overspray booth in operations. In paint overspray booth operations without ventilation system and air pollutants collection unit, it may land on nearby equipment. In this study a removal of sticky paint aerosol for application of the small-scale overspray paint booth. it's cause the surface of filter bag from generated sticky paint aerosol. To remove adhesion of paint aerosol the agglomerating agents are injected and mixed with sticky paint aerosols prior to reach the filter bag. The paint spray rate was set as $10{\pm}5g/min$ from air-atomized spray guns in the spray booth, injection rate of agglomerating was $10{\pm}5g/min$ in the mixing chamber. The filtration velocity including air pollutants varied from 0.2 m/min to 0.4 m/min. Bag cleaning air pressure was set as $5.0kg_f/min$ for detaching dust cake from surface of filter bag. Bag cleaning interval at the filtration velocity of 0.2 m/min was around 3 times longer than that of the 0.4 m/min. The residual pressure drop maintained highest value at the highest filtration velocity. Fractional efficiency of 99.952%~99.971% was possible to maintain for the particle size of 2.5 microns. Total collection efficiency at the filtration velocity of 0.2 m/min was 99.42%. During this study we could confirm high collection efficiency and long cleaning intervals for the test with filtration velocity of 0.2 m/min indicating an optimal value for the given dimensions of the test unit and test operating conditions.

• 한국대기환경학회:학술대회논문집
• /
• 한국대기환경학회 2005년도 추계학술대회 논문집
• /
• pp.193-195
• /
• 2005

• Bulletin of the Korean Chemical Society
• /
• 제23권3호
• /
• pp.488-496
• /
• 2002

SPME techniques have proven to be very useful tools in the analysis of wide VOCs in the air. In this study, we estimated VOCs in ambient and workplace air using a Tedlar ba /SPME/GC/MS system. The calibration curve was set to be linear over the range of 1-30 ppbv. The detection limits ranged from 10 pptv to 0.93 ppbv for all VOCs. Reproducibility of TO-14 target gas mixtures by SPME/GC/MS averaged at 8.8 R.S.D (%). Air toxic VOCs (hazardous air pollutants, HAPs) containing a total of forty halohydrocarbons, aromatics, and haloaro-matic carbons could be analyzed with significant accuracy, detection limit and linearity at low ppbv level. Only reactive VOCs with low molecular weight, such as chloromethane, vinylchloride, ethylchloride and 1,2-dichloro-ethane, yielded relatively poor results using this technique. In ambient air samples, ten VOCs were identified and quantified after external calibration. VOC concentration in ambient and workplace air ranged from 0.04 to 1.85 ppbv. The overall process was successfully applied to identify and quantify VOCs in ambient/workplace air.

• 한국입자에어로졸학회지
• /
• 제4권1호
• /
• pp.9-20
• /
• 2008

The effect of light intensity on the ozone formation and the aerosol number concentration during the photochemical reactions of ambient air was investigated in an indoor smog chamber. The smog chamber consists of a housing, 64 blacklights, and a $2.5-m^3$ reaction bag made of Teflon film. The bag was filled with the unfiltered ambient air in Seoul from January 10 to March 18, 2002. In this work, the photolysis rate of $NO_2$, $k_1$ was used as an index of light intensity. Three levels of light intensity were controlled by changing the number of blacklights turned on among 64 blacklights: $0.29min^{-1}$ (50%), $0.44min^{-1}$ (75%), $0.57min^{-1}$ (100%). The ozone concentration increased rapidly within 10 minutes after irradiation irrespective of light intensity, thereafter it increased linearly during the irradiation. The ozone production rate seems to be dependent on both the light intensity and the quality of ambient air introduced into the reaction bag. The change in aerosol number concentration also depended on both the light intensity and the ambient air quality, especially aerosol size distribution. Based on the initial ambient aerosol size distributions, the photochemical potential for aerosol formation and growth is classified into two cases. One is the case showing aerosol formation and growth processes, and the other is the case showing no apparent change in particle size distribution.

• 한국산학기술학회논문지
• /
• 제18권12호
• /
• pp.57-64
• /
• 2017

오늘날 EU환경규제로 포장용 완충재로 사용되는 EPS(스티로폼) 대체용 공기 충진 완충재는 출시 이후 점진적으로 시장이 확대되는 포장업계 블루칩이다. 공기충진형 완충재는 뛰어난 완충능력과 친환경성으로 EPS를 대체하여 빠르게 시장을 확장하고 있다. 기존 공기 충진 완충재에 대비하여 원료절감과 공정향상, 직관적 미관 향상을 모두 충족하는 새로운 선택 충진형 공기 충진재 제조기술이다. 본 연구는 다단 에어셀 충진 밸브성형기술은 선택충전 기술을 바탕으로, 밸브형성 구조기술을 적용하여 선택적으로 다양한 형태로 충진이 가능한 기술이다. 다단 에어셀 충진 밸브성형기술의 구조도는 밸브단이 구분된 제1주입필름, 밸브필름, 제2주입필름 등 3겹의 필름을 적층하여 복수의 주입구를 형성한 기술이다. 기존의 기술은 연결된 다수의 공기주머니에 공기를 주입하기 위한 별도의 외부 공기주입로가 필수적으로 구성되어야 하나, 본 연구는 공기 주머니의 내부에 외부 공기주입로가 형성되어 공기를 주입하기 위한 외부 공기주입로가 외견상 없어짐으로써 그에 따른 원재료 및 공정이 감소하고, 공기가 주입되어 원형 튜브로 팽창하는 과정에서 단면의 길이가 63~66%로 축소되는 공기주머니와 다르게 공기주입 후 내부 공기가 배출되고 단면이 원래의 길이를 유지하여 불필요하게 접힌 채 붙어 있는 외부 공기주입로를 내부에 일체화 하여 완충재의 미관이 향상되는 기술적 특징과 다수의 연속된 공기주머니에 선택적으로 공기를 충전할 수 있는 선택충전에 관한 것으로 기존 기술대비 뛰어난 차별성을 갖는 스마트한 공기충전형 완충재 제조 기술이다.

• 분석과학
• /
• 제19권1호
• /
• pp.96-102
• /
• 2006

Trimethylamine(이하 TMA)은 물질특성상 시료의 채취 및 분석과 관련하여, 여러 가지 어려운 문제점들을 가지고 있다. 일반적으로 TMA의 채취방법으로 황산용액 흡수법이나 황산여과지 방법을 추천하고있다. 이들 방법은 아직까지 운용상 어려움과 분석시 숙련도를 요구한다. 본문에서는 보조적인 방법으로 Tedlar bag에 기초한 채취 및 SPME 를 이용한 분석기법의 특성에 대해 평가하고자 하였다. Tedlar bag은 시료의 채취 및 보관과 관련한 불안정성, 분석시 재현성 등에 대해 일부 문제점들이 지적받고 있다. 따라서 본 연구에서는 이런 문제점들을 여러 가지 기준으로 평가하고자 하였다. 이를 위해 다음과 같이 3가지 관점에서 비교실험을 수행하였다: (1) Tedlar bag에 TMA 시료를 보존할 때의 경시 변화, (2) Tedlar bag의 표면에 의한 TMA의 흡착 손실 정도, (3) SPME를 이용한 반복 분석시 파이버에 의한 시료의 흡착손실 등을 조사하였다. 최대 20일까지를 기준으로 경시 변화의 경향성을 조사한 결과, 48시간 까지 저농도에서 40~50% 정도로 시료의 감소가 일어났다. 그리고 두 가지 농도대에서 Tedlar bag 내부의 표면흡착에 의한 손실 여부를 평가한 결과, 저농도에서 약 20%, 고농도에서는 5% 이내의 손실을 확인하였다. 또한 동일한 Tedlar bag의 시료를 SPME로 반복분석한 결과, SPME fiber를 반복사용할 때 마다 백내부의 시료가 매회 2-3% 수준 감소하는 것을 확인할 수 있었다.