• Analytical Science and Technology
• /
• v.14 no.6
• /
• pp.494-498
• /
• 2001

In this study, cerium nitrate was used as an alternative to chromate for the surface-treatment of Al coated steel to improve the corrosion resistance. The surface of Al coated steel was characterized by means of a X-ray photoelectron spectroscopy(XPS). It was found that cerium on the surface of Al coated steel had a mixture of oxidation states such as Ce(+4) and Ce(+3), and the relative concentration of each state was 57 % and 43 %, respectively. The surface film consisting of these cerium compounds played an important role for achieving the corrosion resistance of Al coated steel.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
• /
• 2006.05a
• /
• pp.168-171
• /
• 2006

플라스마 디스플레이는 패널내부에 진공상태를 요구하며 작동 중에 발생하는 불순가스에 의해 진공도가 떨어져 소자 수명, 휘도, 방전 개시 전압 등 많은 부분에 문제를 야기시킨다. 이에 불순가스 발생의 원인을 규명하기 위해 PDP에 상용적으로 사용되는 유연 유전체를 이용하여 열적 거동에 의해 불순가스 발생과 고 진공에서의 표면 조도를 분석하였다. $100^{\circ}$에서부터 $H_{2}O$의 가스가 발생되며 $300^{\circ}C$이상에서는 $CO_2$와 함께 가스가 발생하였다. 고 진공에서 표면조도는 상온에서부터 상승하다가 유리 전이점에서 감소하며, 다시 연화점 이상에서 상승하는 것으로 나타났다. 이와 같은 결과는 PDP에서 불순가스 발생의 원인을 규명하기 위한 기초적인 실험이라 할 수 있다.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.15 no.3
• /
• pp.916-923
• /
• 1991

본 연구에서는 표면 균열이 있는 평판의 탄소성 피로하중 상태에서 성장하는 균열 형태의 변화와, 작용하는 응력의 크기에 따른 균열 개페구 특성의 변화를 연구하 였다.또, 유효 응력 확대계수 범위, .DELTA.K$_{eff}$와 J적분범위, .DELTA.J가 탄소성 응력 상태에서의 표면 피로균열 진전속도를 나타내는 역학양으로 사용되는데 따른 적합성등 을 검토하였다.

• Annual Conference of KIPS
• /
• 2022.05a
• /
• pp.438-440
• /
• 2022

산업 현장에서 인력으로 작업할 수 있는 물리적 한계를 극복하기 위해 특수 목적 차량 작업 시 차량의 넘어짐 방지와 차체 보호를 위해 아웃트리거를 착지시키는데 도로 상태에 따라 사용자가 직접 최적화를 수행하는데 어려움이 존재한다. 본 논문에서는 도로 표면 상태를 신속하게 판단하여 아웃트리거 수직 및 수평 전개 착지 시 시간 소모, 안전사고 발생을 낮추기 위해 시멘틱 분할을 이용한 도로 표면 상태를 분석하는 연구를 수행하였다. 13가지로 구분된 도로 표면 상황에 대하여 DeepLabV3+를 통해 실험한 결과 픽셀 성능0.7819, mIoU 0.7085 결과를 도출하였다.

• Journal of Convergence for Information Technology
• /
• v.11 no.5
• /
• pp.267-275
• /
• 2021

Skin condition is an important concern in beauty aspect. This study considered a rough skin condition analysis method that beauty industry workers can do through visual observation or skin condition images taken with smartphones. First, studies that combine subjective and objective evaluations were selected among degree papers and academic papers searched by keywords related to 'skin condition' in the Research Information Sharing Service(RISS). Among them, papers that derive correlations with visually verifiable factors were selected. Next, the relationship between factors that match subjective skin condition and objective skin measurement results and factors that can be visually identified on the skin surface was investigated. According to the study, the most suitable factor for matching subjective and objective evaluations was 'oil volume', which is significantly related to 'pore', 'skin texture' and 'erythema', which can be visually checked on the skin surface. It is believed that a rough skin condition analysis will be possible using this.

• Korean Chemical Engineering Research
• /
• v.53 no.5
• /
• pp.614-619
• /
• 2015

A plasma surface modification of powders has been carried out in a circulating fluidized bed reactor under reduced pressure. Polystyrene (PS) particles treated by plasma are grafted with polyethylene glycol (PEG) on the surface. The virgin, plasma-treated and grafted powders were characterized by DPPH method, FTIR, SEM and contact angle meter. The plasma-treated PS powders have well formed peroxide on the surface, By PEG grafting polymerization, PEG is well grafted and dispersed on the surface of the plasma-treated PS powders. The PEG-g-PS particle was successfully synthesized using the plasma circulating fluidized bed reactor under reduced pressure.

• Proceedings of the Korean Vacuum Society Conference
• /
• 1999.07a
• /
• pp.236-236
• /
• 1999

AC-PDP(Plasma display Panel)는 기체 방전을 이용한 디스플레이로서 기체에 직접 노출되는 MgO 보호막의 이차전자 방출계수(${\gamma}$)는 AC-PDP의 방전특성을 결정짓는 중요한 요소이다. MgO 보호막의 이차전자 방출계수는 AC-PDP에 주입하는 기체의 종류, 결정 방향성과 표면오염상태등에 영향을 받는다. 본 연구에서는 MgO 보호막을 열처리한 상태와 열처리 하지 않은 상태를 ${\gamma}$-FIB 장치를 이용하여 2차전자방출 계수를 측정하여 비교하였다. 또한 24시간 MgO 보호막을 대기중에 방치하여 두었을 때 MgO 보호막의 표면오염상태에 대한 2차전자방출계수값을 측정하여 MgO 보호막의 표면오염에 대한 방전 전압특성저하가 어느정도인지를 알아보았다. 실험에 사용한 혼합기체는 Ne+Xe, He+Ne+Xe 혼합기체를 사용하였고, MgO 보호막은 21inch 규격의 실제 PDP Panel의 MgO 보호막을 사용하였다.

• International Journal of Highway Engineering
• /
• v.3 no.4 s.10
• /
• pp.117-126
• /
• 2001

In this research, evaluation of adhesion in tension property of SBR-modified concrete to ordinary portland cement concrete was conducted with uniaxial direct tensile bond test which was proposed by Kuhlmann. A test set-up was fabricated in order to minimize the eccentric force by introducing a joint which might fully rotate. The main experimental variables were cement-latex ratios, surface preparations and moisture levels. The results obtained were as follows: The LMC specimen at 15% latex-cement ratio increased the adhesion in tension by range of 37% compared to that of conventional cement concrete. This might be due to latex film formed between cement paste and aggregate. The effects of surface preparation on bond of latex modified concrete to conventional concrete were significant at the conditions by sand paper and wire brush. A better bond could be achieved by rough surface rather than smooth. The saturated and surface dry (SSD) condition were considered to be the most appropriate moisture level followed by wet, finally by dry. Thus, a proper surface preparation and moisture level are quite necessity in order to obtain better bonding at LMC overlay.

• Journal of the Korean Magnetics Society
• /
• v.25 no.6
• /
• pp.175-179
• /
• 2015

The half-metallicity and magnetism of the (001) surfaces of $(AlP)_1/(CrP)_1$ superlattice were investigated by means of FLAPW (Full-potential Liniarized Augmented Plane Wave) method. We considered four types of (001) surface termination, i.e., Al(S)-, Cr(S)-, P(S)Al(S-1)- and P(S)Cr(S-1)-term systems. We found that only Cr(S)-term system maintains the half-metallicity at the surface as only this system has the calculated magnetic moment of integer number of bohr magnetons. The magnetic moment of Cr(S) atom in the system was $3.02{\mu}_B$ which was increased from the bulk value by the effects of band narrowing and increased spin-splitting at the surface. The electronic density of states of the P(S) atom in the P(S)Al(S-1)-term showed very sharp surface states due to the broken $p_z$ bonds at the surface. We found there is still a strong p-d hybridization between the P(S) and Cr(S-1) layers in the P(S)Cr(S-1)-term which causes a considerable increase of magnetic moment of P(S) atom.

• Journal of the Korean Magnetics Society
• /
• v.15 no.5
• /
• pp.257-260
• /
• 2005

We investigated the half-metallicity and magnetism for the zinc-blende CrS(001) surfaces by use of the full-potential linearized augmented plane wave (FLAPW) method. We considered two-types of (001) surfaces terminated by Cr (Cr-Term) and S (S-Term) atoms, respectively. From the calculated layer-by-layer density of states, it is found that both of the systems retain the half-metallicity at the (001) surfaces. The calculated magnetic moment ($4.07\;{\mu}_B$) for the CrS(S) atom in Cr-Term is enhanced considerably compared to the bulk value ($3.61\;{\mu}_B$) while that ($3.15\;{\mu}_B$) of the Cr(S-1) in S-Term is much reduced.