Indium-Free Amorphous Ca-Al-O Thin Film as a Transparent Conducting Oxide

Sim, So Hee,Kang, Kyeong Tae,Lee, Sangyun,Lee, Miso,Taniguchi, Hiroki,Kim, Suyoung,Roh, Seulki,Oh, Jun Hyeob,Lee, Sang A,Bae, Jong-Seong,Jang, Jae Hyuck,Hwang, Jungseek,Han, Seungwu,Park, Tuson,Choi, American Chemical Society 2019 Chemistry of materials Vol.31 No.19

<P>Transparent conducting oxide (TCO) is a promising material system for transparent electrodes, which is one of the most essential elements in current electronic and energy devices. In particular, In-based TCOs such as Sn:In<SUB>2</SUB>O<SUB>3</SUB> (ITO) and In-Ga-Zn-O (IGZO) have shown large optical band gap and high electrical conductivity, sufficient for the applications. However, In is an expensive element, which hampers its facile industrial application. Moreover, In-based TCOs show an abrupt decrease in conductivity when their thickness decreases below ∼100 nm, possibly due to inhomogeneity within the thin films. Here, we introduce an amorphous Ca-Al-O (CAO) thin film as a promising candidate for the In-free TCOs. The amorphous CAO thin film has very low resistivity (∼10<SUP>-5</SUP> Ω cm) at room temperature, as well as high transparency in the visible region of the light spectrum (>80%). The isotropic Ca <I>s</I>-orbital in the conduction band is found to be responsible for the superior performance of CAO as a TCO. Owing to the exceptional structural homogeneity of the CAO thin film, thickness-independent transport characteristics are observed, maintaining its TCO performance down to 10 nm of thickness.</P> [FIG OMISSION]</BR>

피스톤 핀과 링의 코팅 재질에 따른 엔진 마찰력 저감에 대한 시험적 고찰

심대곤(Daegon Sim),김수영(·Suyoung Kim) 한국자동차공학회 2014 한국자동차공학회 학술대회 및 전시회 Vol.2014 No.11

One important development area for better fuel economy is to reduce mechanical friction losses in engine components. Especially the friction reduction of piston assembly of which account for 30-50% of total engine friction is significantly effective method. This paper describes the friction reduction effect of DLC(diamond-like carbon) coatings and ZALC(ZrAlCu) coatings at the piston pin and rings by engine test. In the case of DLC and ZALC coating pin, the friction torque was decreased at all engine speed and the friction reduction effect was good at low oil temperature condition. In the case of DLC and ZALC coating rings, the friction torque was decreased at high engine speed but the friction torque was increased at low engine speed. Test results show that ZALC coating is more effective than DLC coating by 2%.

ESTEREL을 이용한 RTOS Scheduler 의 검증 및 구현

양진석(Jinseok Yang),김진현(Jinhyun Kim),심재환(Jaehwan Sim),이수영(Suyoung Lee),최진영(Jinyoung Choi) 한국정보과학회 2004 한국정보과학회 학술발표논문집 Vol.31 No.2Ⅰ

오늘날 RTOS가 운영되는 시스템이 고안정성을 요구 할수록 임베디드 소프트웨어인 RTOS 의 중요성은 날이 갈수록 증대하고 있다. 검증된 RTOS의 개발을 목표로 본 논문에서는 RTOS의 태스크 스케쥴러를 정형명세하고, 정형명세된 스케쥴러가 가져야 하는 몇가지의 검증특성들을 모덜체킹 기법을 통해서 검증하였다. 또한 에스테럴로 정형 명세된 스케쥴러에서 자동 생성된 C 소스를 사용하여 직접 태스크를 스케쥴해 주는 간단한 RTOS 를 제작함으로서 검증된 RTOS 를 제작 할 수 있는 방법을 제시 하고자 한다.

Evaluation of GSICS Correction for COMS/MI Visible Channel Using S-NPP/VIIRS

( Donghyun Jin ),( Soobong Lee ),( Seonyoung Lee ),( Daeseong Jung ),( Suyoung Sim ),( Morang Huh ),( Kyung-soo Han ) 대한원격탐사학회 2021 大韓遠隔探査學會誌 Vol.37 No.1

The Global Space-based Inter-Calibration System (GSICS) is an international partnership sponsored by World Meteorological Organization (WMO) to continue and improve climate monitoring and to ensure consistent accuracy between observation data from meteorological satellites operating around the world. The objective for GSICS is to inter-calibration from pairs of satellites observations, which includes direct comparison of collocated Geostationary Earth Orbit (GEO)-Low Earth Orbit (LEO) observations. One of the GSICS intercalibration methods, the Ray-matching technique, is a surrogate approach that uses matched, co-angled and colocated pixels to transfer the calibration from a well calibrated satellite sensor to another sensor. In Korea, the first GEO satellite, Communication Ocean and Meteorological Satellite (COMS), is used to participate in the GSICS program. The National Meteorological Satellite Center (NMSC), which operated COMS/MI, calculated the Radiative Transfer Model (RTM)-based GSICS coefficient coefficients. The L1P reproduced through GSICS correction coefficient showed lower RMSE and Bias than L1B without GSICS correction coefficient applied. The calculation cycles of the GSICS correction coefficients for COMS/MI visible channel are provided annual and diurnal (2, 5, 10, 14-day), but long-term evaluation according to these cycles was not performed. The purpose of this paper is to perform evaluation depending on the annual/diurnal cycles of COMS/MI GSICS correction coefficients based on the ray-matching technique using Suomi-NPP/Visible Infrared Imaging Radiometer Suite (VIIRS) data as reference data. As a result of evaluation, the diurnal cycle had a higher coincidence rate with the reference data than the annual cycle, and the 14-day diurnal cycle was the most suitable for use as the GSICS correction coefficient.

Uncertainty analysis of BRDF Modeling Using 6S Simulations and Monte-Carlo Method

( Kyeong-sang Lee ),( Minji Seo ),( Sungwon Choi ),( Donghyun Jin ),( Daeseong Jung ),( Suyoung Sim ),( Kyung-soo Han ) 대한원격탐사학회 2021 大韓遠隔探査學會誌 Vol.37 No.1

This paper presents the method to quantitatively evaluate the uncertainty of the semi-empirical Bidirectional Reflectance Distribution Function (BRDF) model for Himawari-8/AHI. The uncertainty of BRDF modeling was affected by various issues such as assumption of model and number of observations, thus, it is difficult that evaluating the performance of BRDF modeling using simple uncertainty equations. Therefore, in this paper, Monte-Carlo method, which is most dependable method to analyze dynamic complex systems through iterative simulation, was used. The 1,000 input datasets for analyzing the uncertainty of BRDF modeling were generated using the Second Simulation of a Satellite Signal in the Solar Spectrum (6S) Radiative Transfer Model (RTM) simulation with MODerate Resolution Imaging Spectroradiometer (MODIS) BRDF product. Then, we randomly selected data according to the number of observations from 4 to 35 in the input dataset and performed BRDF modeling using them. Finally, the uncertainty was calculated by comparing reproduced surface reflectance through the BRDF model and simulated surface reflectance using 6S RTM and expressed as bias and root-meansquare- error (RMSE). The bias was negative for all observations and channels, but was very small within 0.01. RMSE showed a tendency to decrease as the number of observations increased, and showed a stable value within 0.05 in all channels. In addition, our results show that when the viewing zenith angle is 40° or more, the RMSE tends to increase slightly. This information can be utilized in the uncertainty analysis of subsequently retrieved geophysical variables.

Comparison of Land Surface Temperature Algorithm Using Landsat-8 Data for South Korea

( Sungwon Choi ),( Kyeong-sang Lee ),( Minji Seo ),( Noh-hun Seong ),( Donghyun Jin ),( Daeseong Jung ),( Suyoung Sim ),( Im Gook Jung ),( Kyung-soo Han ) 대한원격탐사학회 2021 大韓遠隔探査學會誌 Vol.37 No.1

Land Surface Temperature (LST) is the radiological surface temperature which observed by satellite. It is very important factor to estimate condition of the Earth such as Global warming and Heat island. For these reasons, many countries operate their own satellite to observe the Earth condition. South Korea has many landcovers such as forest, crop land, urban. Therefore, if we want to retrieve accurate LST, we would use high-resolution satellite data. In this study, we made LSTs with 4 LST retrieval algorithms which are used widely with Landsat-8 data which has 30 m spatial resolution. We retrieved LST using equations of Price, Becker et al. Prata, Coll et al. and they showed very similar spatial distribution. We validated 4 LSTs with Moderate resolution Imaging Spectroradiometer (MODIS) LST data to find the most suitable algorithm. As a result, every LST shows 2.160 ~ 3.387 K of RMSE. And LST by Prata algorithm show the lowest RMSE than others. With this validation result, we choose LST by Prata algorithm as the most suitable LST to South Korea.

동아시아 지역의 위성 구름탐지 산출물 상호 비교를 통한 품질 평가

변유경 ( Yugyeong Byeon ),최성원 ( Sungwon Choi ),진동현 ( Donghyun Jin ),성노훈 ( Noh-hun Seong ),정대성 ( Daeseong Jung ),심수영 ( Suyoung Sim ),우종호 ( Jongho Woo ),전우진 ( Uujin Jeon ),한경수 ( Kyung-soo Han ) 대한원격탐사학회 2021 大韓遠隔探査學會誌 Vol.37 No.6

구름탐지란 위성영상내의 픽셀 혹은 화소에서의 구름 유무를 결정하는 것을 의미하며 해당 위성영상의 활용성과 정확도에 영향을 미치는 중요한 요소로 작용한다. 본 연구에서는 구름탐지 자료를 제공해주는 여러 선진기관들의 위성 중에서, GK-2A(GeoKompsat-2A)/AMI(Advanced Meteorological Imager)와 Terra(Earth Observation System-Terra)/MODIS(Moderate-Resolution Imaging Spectroradiometer), Suomi-NPP(The Suomi National Polar-orbiting Partnership)/VIIRS(Visible Infrared Imaging Radiometer Suite)의 구름탐지 자료의 차이에 대해서 정량적 및 정성적으로 비교 분석을 수행하고자 한다. 정량적으로 비교한 결과 1월의 Proportion Correct (PC)지수 값이 GK-2A & MODIS가 74.16%, GK-2A & VIIRS가 75.39%를 나타냈으며 4월의 GK-2A & MODIS는 87.35%, GK-2A & VIIRS는 87.71%로 4월이 1월보다 위성별로 큰 차이 없이 구름을 탐지한 것으로 나타났다. 정성적 비교 결과는 RGB영상과 비교하였을 때, 앞선 정량적 결과들의 경향과 동일하게 1월보다 4월에 해당하는 결과들이 구름을 잘 탐지한 것을 확인할 수 있었으나 얇은 구름이나 적설이 존재하는 경우에는 위성별로 구름탐지 결과에 다소 차이가 존재하였다. Cloud detection means determining the presence or absence of clouds in a pixel in a satellite image, and acts as an important factor affecting the utility and accuracy of the satellite image. In this study, among the satellites of various advanced organizations that provide cloud detection data, we intend to perform quantitative and qualitative comparative analysis on the difference between the cloud detection data of GK-2A/AMI, Terra/MODIS, and Suomi-NPP/VIIRS. As a result of quantitative comparison, the Proportion Correct (PC) index values in January were 74.16% for GK-2A & MODIS, 75.39% for GK-2A & VIIRS, and 87.35% for GK-2A & MODIS in April, and GK- 2A & VIIRS showed that 87.71% of clouds were detected in April compared to January without much difference by satellite. As for the qualitative comparison results, when compared with RGB images, it was confirmed that the results corresponding to April rather than January detected clouds better than the previous quantitative results. However, if thin clouds or snow cover exist, each satellite were some differences in the cloud detection results.

Sentinel-2A 위성자료를 활용한 선박 및 후류 탐지 개선

전우진 ( Uujin Jeon ),서민지 ( Minji Seo ),성노훈 ( Noh-hun Seong ),최성원 ( Sungwon Choi ),심수영 ( Suyoung Sim ),변유경 ( Yugyeong Byeon ),한경수 ( Kyung-soo Han ) 대한원격탐사학회 2021 大韓遠隔探査學會誌 Vol.37 No.3

최근 증가된 해상 교통량의 영향으로 지속적으로 발생하는 선박사고에 대한 신속한 탐지 및 대처가 필요하다. 이를 위해, 광역 범위로 실시간 모니터링이 가능한 위성영상을 기반으로 선박탐지 연구가 활발히 수행되고 있다. 그러나, 분광특성을 활용하여 선박탐지를 수행한 선행연구에서는 후류(Wake) 제거를 수행하지 않아 후류가 선박으로 오탐지될 가능성이 존재한다. 이에 본 연구에서는 Ship Detection Index (SDI)를 이용하여 Sentinel-2A/Multispectral Instrument (MSI) 위성영상에서 선박탐지를 수행하고 선박과 후류의 분광특성 차이를 기반으로 하는Wake Detection Index (WDI)를 활용하여 후류를 제거하였다. 본 연구의 선박탐지 알고리즘의 정확도 검증을 위해 Probability of detection (POD), False alarm rate (FAR) 지수를 활용하였으며, 검증 결과 SDI만 적용한 결과에 비해 POD는 유사하게 나타나고 FAR는 6.4% 개선되었다. It is necessary to quickly detect and respond to ship accidents that occur continuously due to the influence of the recently increased maritime traffic. For this purpose, ship detection research is being actively conducted based on satellite images that can be monitored in real time over a wide area. However, there is a possibility that the wake may be falsely detected as a ship because the wake removal is not performed in previous studies that performed ship detection using spectral characteristics. Therefore, in this study, ship detection was performed using SDI (Ship Detection Index) based on the Sentinel-2A satellite image, and the wake was removed by utilizing the difference in the spectral characteristics of the ship and the wake. Probability of detection (POD) and false alarm rate (FAR) indices were used to verify the accuracy of the ship detection algorithm in this study. As a result of the verification, POD was similar and FAR was improved by 6.4% compared to the result of applying only SDI.

폐 FRP 선박의 실질적 재활용 연구

연주한(Juhan Yeon),박용준(Yongjun Park),구자영(Jayoung Gu),홍상기(Sangki Hong),이수영(Suyoung Lee),심명규(Myoungkyu Sim) 한국해양환경·에너지학회 2007 한국해양환경·에너지학회 학술대회논문집 Vol.2007 No.-

세계 각국에서는 FRP선박의 폐처리 또는 재활용(재자원화)을 위하여 실용성과 안정성을 지니는 많은 기계적 방법에 대한 연구 개발을 진행하여왔다. 그러나 많은 연구가 진행되어 왔음에도 기계적 처리 방법의 두 가지 문제, 즉 파쇄공정 중의 2차 오염 및 재자원화 용도의 한계가 아직도 기계적 재활용의 확대를 어렵게 하고 있다. 실제 폐 FRP선발의 구성을 확인한 후 실질적인 선박의 재활용 기술과 경제적, 친환경적 기술을 통한 폐 FRP 선박의 재처리/재활용기술을 연구한다. Since 1990s, these many researchers have been fully involved in developing recycling methods for FRP boats. There are four basic classes of recycling covered in the literature. the first is "Mechanical recycling" which involves shredding and grinding of the scrap FRP in a new product. Despite of the safety hazards, mechanical recycling is one of the simpler and more technically proven methods. Recent researchers should be more interested in these methods. It is fact that most of FRP wastes are depend려 on incineration or reclamation. Because it is made up of reinforced fiber glass, it is very difficult to break into pieces. By the disposing of waste FRP this way, it also occurs secondary problem such as air pollution and unacceptable noise. This study is to propose a new method which is efficient and environment friendly waste FRP regenerating.

천리안위성 1·2A호 지표면 알베도 상호 오차 분석 및 비교검증

우종호 ( Jongho Woo ),최성원 ( Sungwon Choi ),진동현 ( Donghyun Jin ),성노훈 ( Noh-hun Seong ),정대성 ( Daeseong Jung ),심수영 ( Suyoung Sim ),변유경 ( Yugyeong Byeon ),전우진 ( Uujin Jeon ),손은하 ( Eunha Sohn ),한경수 ( Kyung-so 대한원격탐사학회 2021 大韓遠隔探査學會誌 Vol.37 No.6

장기간에 걸친 전 지구적인 위성관측 지표면 알베도 자료는 전 지구 기후 및 환경의 변화 감시에 활발히 이용되고 있으며 그 활용도와 중요성이 크다. 우리나라의 경우 정지궤도위성 천리안위성 1호(Communication, Ocean and Meteorological Satellite, COMS) MI(Meteorological Imager) 센서와 천리안위성 2A호(GEO-KOMPSAT-2A, GK-2A) AMI (Advanced Meteorological Imager) 센서의 세대교체를 통해 지속적인 지표면 알베도 산출물의 확보가 가능하다. 그러나 COMS/MI 및 GK-2A/AMI의 지표면 알베도 산출물은 센서 및 알고리즘의 차이로 인해 산출물 간의 차이가 존재한다. 따라서 COMS/MI와 GK-2A/AMI 지표면 알베도 산출 기간을 확장하고 지속적인 기후변화 감시 연계성 확보를 위해 두 위성 산출물 간의 오차 분석이 선행되어야 한다. 본 연구에서는 COMS/MI 및 GK-2A/AMI 지표면 알베도 자료의 중복기간을 대상으로 지상관측자료 AERONET (Aerosol Robotic Network)와 타 위성자료 GLASS (Global Land Surface Satellite)와 함께 비교 분석하였다. 오차 분석 결과 AERONET과의 검증에서 COMS/MI의 평균 제곱근 오차(Root Mean Square Error, RMSE)가 0.043로 GK-2A/AMI의 RMSE인 0.015보다 높게 나타났다. 또한GLASS와 비교하였을 때 COMS/MI의 RMSE는 0.029로GK-2A/AMI의 0.038보다 낮게 나타났다. 이러한 오차특성을 이해하고 COMS/MI 및 GK-2A/AMI의 지표면 알베도 자료를 사용할 때 장기간 기후변화 감시에 적극적으로 활용할 수 있을 것이다. Global satellite observation surface albedo data over a long period of time are actively used to monitor changes in the global climate and environment, and their utilization and importance are great. Through the generational shift of geostationary satellites COMS (Communication, Ocean and Meteorological Satellite)/MI (Meteorological Imager sensor) and GK-2A (GEO-KOMPSAT-2A)/AMI (Advanced Meteorological Imager sensor), it is possible to continuously secure surface albedo outputs. However, the surface albedo outputs of COMS/MI and GK-2A/AMI differ between outputs due to differences in retrieval algorithms. Therefore, in order to expand the retrieval period of the surface albedo of COMS/MI and GK-2A/AMI to secure continuous climate change monitoring linkage, the analysis of the two satellite outputs and errors should be preceded. In this study, error characteristics were analyzed by performing comparative analysis with ground observation data AERONET (Aerosol Robotic Network) and other satellite data GLASS (Global Land Surface Satellite) for the overlapping period of COMS/MI and GK-2A/AMI surface albedo data. As a result of error analysis, it was confirmed that the RMSE of COMS/MI was 0.043, higher than the RMSE of GK-2A/AMI, 0.015. In addition, compared to other satellite (GLASS) data, the RMSE of COMS/MI was 0.029, slightly lower than that of GK-2A/AMI 0.038. When understanding these error characteristics and using COMS/MI and GK-2A/AMI’s surface albedo data, it will be possible to actively utilize them for long-term climate change monitoring.