Essential macleod program (EMP) was used to optimize the transmittance of the transparent conducting layers in an oxidemetal- oxide structure. For EMP simulation, the optical coefficient of the material was extracted using an ellipsometer. Following the simulation studies, oxide-metal-oxide samples were fabricated experimentally, and their optical and electrical properties were analyzed. Multilayer SiInZnO/Ag/Siinzno (S/A/S) structures were grown on glass substrates using radio frequency (RF) and direct current (DC) sputtering at room temperature. Due to the occurrence of destructive interference at the metal and oxide interface, the S/A/S structure exhibited excellent optical properties. As the thickness of the top and bottom oxide layers was increased, the transmittance spectrum was red-shifted due to partial wave interference at the Ag interface. Change in thickness of the top oxide layer had a greater effect on the transmittance than that of the bottom oxide layer. This was due to the difference in refractive index occurring at each interface. Change in Ag thickness shifted the absorption edge in the short wavelength region. Whereas electrical properties, such as sheet resistance and carrier concentration, were found to be dependent on thickness of the sandwiched metal layer. An excellent figure of merit of 63.20 ×10−3Ω−1 was obtained when the thickness of the Ag layer was 11 nm, and the top and bottom oxide layer thickness were 45 and 60 nm, respectively. These values suggest promising optoelectronic properties and are encouraging for future transparent electrode applications.

We present an updated version of the multilayer spectral inversion (MLSI) recently proposed as a technique to infer the physical parameters of plasmas in the solar chromosphere from a strong absorption line. In the original MLSI, the absorption prole was constant over each layer of the chromosphere, whereas the source function was allowed to vary with optical depth. In our updated MLSI, the absorption prole is allowed to vary with optical depth in each layer and kept continuous at the interface of two adjacent layers. We also propose a new set of physical requirements for the parameters useful in the constrained model tting. We apply this updated MLSI to two sets of Hα and Ca ii line spectral data taken by the Fast Imaging Solar Spectrograph (FISS) from a quiet region and an active region, respectively. We nd that the new version of the MLSI satisfactorily ts most of the observed line proles of various features, including a network feature, an internetwork feature, a mottle feature in a quiet region, and a plage feature, a superpenumbral bril, an umbral feature, and a fast down ow feature in an active region. The MLSI can also yield physically reasonable estimates of hydrogen temperature and nonthermal speed as well as Doppler velocities at different atmospheric levels. We conclude that the MLSI is a very useful tool to analyze the Hα line and the Ca ii 8542 line spectral daya, and will promote the investigation of physical processes occurring in the solar photosphere and chromosphere.

온도와 상대습도는 작물 재배에 있어서 중요한 요소로써, 수량과 품질의 증대를 위해서는 적절히 제어 되어야 한다. 그리고 정확한 환경 제어를 위해서는 환경이 어떻게 변화할지 예측할 필요가 있다. 본 연구의 목적은 현 시점의 환경 데이터를 이용한 다층 퍼셉트론(multilayer perceptrons, MLP)을 기반으로 미래 시점의 기온 및 상 대습도를 예측하는 것이다. MLP 학습에 필요한 데이터는 어윈 망고(Mangifera indica cv. Irwin)을 재배하는 8 연동 온실(1,032m2)에서 2016년 10월 1일부터 2018년 2 월 28일까지 10분 간격으로 수집되었다. MLP는 온실 내부 환경 데이터, 온실 외 기상 데이터, 온실 내 장치의 설정 및 작동 값을 사용하여 10~120분 후 기온 및 상대습도를 예측하기 위한 학습을 진행하였다. 사계절이 뚜렷한 우리나라의 계절에 따른 예측 정확도를 분석하기 위해서 테스트 데이터로 계절별로 3일간의 데이터를 사 용했다. MLP는 기온의 경우 은닉층이 4개, 노드 수가 128개일 때(R2 = 0.988), 상대습도는 은닉층 4개, 노드 수 64개에서 가장 높은 정확도를 보였다(R2 = 0.990). MLP 특성상 예측 시점이 멀어질수록 정확도는 감소하 였지만, 계절에 따른 환경 변화에 무관하게 기온과 상대 습도를 적절히 예측하였다. 그러나 온실 내 환경 제어 요소 중 분무 관수처럼 특이적인 데이터의 경우, 학습 데이터 수가 적기 때문에 예측 정확도가 낮았다. 본 연구에서는 MLP의 최적화를 통해서 기온 및 상대습도를 적절히 예측하였지만 실험에 사용된 온실에만 국한되었다. 따라서 보다 일반화를 위해서 다양한 장소의 온실 데이터 이용과 이에 따른 신경망 구조의 변형이 필요하다.

Stainless steel is being used in various industries such as automobile and aerospace for its cheap manufacturing cost and excellent mechanical properties. However, stainless steel failed to stably protect a specimen with a Cr2O3 protective layer at temperatures above 1000 ℃. Thus, improving the high temperature flame resistance of the specimen through additional surface coating was needed. In this study, multilayer coatings of YSZ and Al2O3 were performed on SUS 304 specimens using pack cementation coatings and thermal plasma spray. The multilayer coated specimen showed enhanced thermal properties due to the coated layers. The microstructures and phase stability are discussed together with flame conditions at 1350 ℃.

ZnMgBeGaO/Ag/ZnMgBeGaO multilayer structures were sputter grown and characterized in detail. Results indicated that the electrical properties of the ZnMgBeGaO films were significantly improved by inserting an Ag layer with proper thickness (~ 10 nm). Structures with thicker Ag films showed much lower optical transmission, although the electrical conductivity was further improved. It was also observed that the electrical properties of the multilayer structure were sizably improved by annealing in vacuum (~35% at 300 oC). The optimum ZnMgBeGaO(20nm)/Ag(10nm)/ZnMgBeGaO(20nm) structure exhibited an electrical resistivity of ~2.6 × 10−5 Ωcm (after annealing), energy bandgap of ~3.75 eV, and optical transmittance of 65%~ 95 % over the visible wavelength range, representing a significant improvement in characteristics versus previously reported transparent conductive materials.

목 적: 곡률이 없는 안경렌즈 위에 나노 구조 층을 포함한 안경렌즈 3층 코팅 막의 반사방지에 관한 연구 를 하였다. 방 법: 시뮬레이터 설계에서 안경렌즈 위에 하드코팅 막을, 그 위에 Al2O3/ ZrO2/Al2O3(나노 구조) 막을 쌓았다. 원기둥 hole 반경, 두께, 주기와 ZrO2 막의 두께에 따른 반사율 스펙트럼을 관찰하여 최적의 반사 방지막을 찾았다. 결 과: 나노 원기둥 hole 주기와 두께를 고정하고 반경을 변화시키면서 반사율 스펙트럼을 관찰한 결과, 반경이 70 nm일 때 파장 450 nm에서 650 nm까지 반사율이 0%에 가까웠다. 그리고 나노 원기둥 hole 주기와 반경을 고정하고 두께를 변화시키면서 반사율 스펙트럼을 관찰한 결과, 나노 원기둥 hole 높이가 약 100 nm 에서 최적의 반사율 스펙트럼을 얻을 수 있었다. 또한 나노 원기둥 hole 주기와 반경을 변화시키면서 반사율 스펙트럼을 관찰한 결과, 주기 200 nm 이하에서는 최적의 반사율 스펙트럼을 나타내었다. ZrO2 막의 두께를 변화시킨 결과 130 nm에서 반사방지막 코팅이 최적화됨을 알 수 있었다. 결 론: Al2O3/ ZrO2/Al2O3(나노 구조) 막으로 이루어진 안경렌즈 3층 코팅 막의 반사방지막에 관한 연구 한 결과, 나노 원기둥 hole 반경은 70 nm에서, 높이는 100 nm에서, 주기는 200 nm 이하에서, ZrO2 막의 두께는 130 nm에서 반사율 스펙트럼이 최적이 되었다.

There have been many studies on superwetting surfaces, ranging from superhydrophilicity to superhydrophobicity, owing to the variety of their potential applications. There are some drawbacks to developing these films for certain applications, such as the fragility of the microscopic roughness feature that is vital to ensure superwettability. At the first part of in this presentation, we fabricated intrinsically stable superwetting films using the organosilicate based layer-by-layer (LbL) self-assembly method in order to control hierarchical roughness and adjusted the surface chemistry of the multilayer structures. At the second part, hydrophilic branched poly(ethylenimine) and nanoparticle were assembled into LbL multilayers in the presence of UV-curable poly(urethane acrylate).