• 제목/요약/키워드: Gap-filling

검색결과 181건 처리시간 0.025초

Spatial Gap-Filling of Hourly AOD Data from Himawari-8 Satellite Using DCT (Discrete Cosine Transform) and FMM (Fast Marching Method)

  • Youn, Youjeong;Kim, Seoyeon;Jeong, Yemin;Cho, Subin;Kang, Jonggu;Kim, Geunah;Lee, Yangwon
    • 대한원격탐사학회지
    • /
    • 제37권4호
    • /
    • pp.777-788
    • /
    • 2021
  • Since aerosol has a relatively short duration and significant spatial variation, satellite observations become more important for the spatially and temporally continuous quantification of aerosol. However, optical remote sensing has the disadvantage that it cannot detect AOD (Aerosol Optical Depth) for the regions covered by clouds or the regions with extremely high concentrations. Such missing values can increase the data uncertainty in the analyses of the Earth's environment. This paper presents a spatial gap-filling framework using a univariate statistical method such as DCT-PLS (Discrete Cosine Transform-based Penalized Least Square Regression) and FMM (Fast Matching Method) inpainting. We conducted a feasibility test for the hourly AOD product from AHI (Advanced Himawari Imager) between January 1 and December 31, 2019, and compared the accuracy statistics of the two spatial gap-filling methods. When the null-pixel area is not very large (null-pixel ratio < 0.6), the validation statistics of DCT-PLS and FMM techniques showed high accuracy of CC=0.988 (MAE=0.020) and CC=0.980 (MAE=0.028), respectively. Together with the AI-based gap-filling method using extra explanatory variables, the DCT-PLS and FMM techniques can be tested for the low-resolution images from the AMI (Advanced Meteorological Imager) of GK2A (Geostationary Korea Multi-purpose Satellite 2A), GEMS (Geostationary Environment Monitoring Spectrometer) and GOCI2 (Geostationary Ocean Color Imager) of GK2B (Geostationary Korea Multi-purpose Satellite 2B) and the high-resolution images from the CAS500 (Compact Advanced Satellite) series soon.

국제거래상 신의성실의 원칙에 관한 연구 - CISG를 중심으로 - (A Study on the Principles of Good Faith under International Transaction -Focused on the CISG-)

  • 한낙현
    • 무역상무연구
    • /
    • 제46권
    • /
    • pp.61-104
    • /
    • 2010
  • The purpose of this work aims to analyse the principles of good faith under international transaction with CLOUT and UNILEX cases. Article 7(1) CISG sets the stage for the interpretation by promoting a uniform approach using good faith and the international charter of the convention. In other words, article 7(1) defines the purpose and the principle of interpretation and is applied to the Convention as a whole. As such, it also includes article 7(2), which goes beyond the big picture and settles the problems of gap filling. It is also important to understanding that the mandate of the CISG is to look for a solution, which is not only restricted to interpretation but extends to solving a problem. The problem in this work is to find out how gap filling is achieved and, because of the autonomous mandate of interpretation, to explain and understand its relationship with domestic law. The solution to the interpretation of article 7(2) must be found within the four corners of the CISG. To restate, article 7(2) describes two situations where gap filling is needed. First, if the matter is governed by the Convention but not expressly settled, then a gap must be filled in conformity with general principles on which it is based. Second, if the matter is not covered then the gap must be filled taking domestic law into consideration. There are two reasons why a matter may not be covered by the Convention. First and most obviously, it has been specifically exclude from the sphere of Application by the CISG itself, such as validity in article 4. Second, changes in business methods will lead to gaps. The United Nations has established a service known as CLOUT. This contains abstracts of hundreds of selected decisions of both courts and arbitration tribunals. And UNILEX is cosponsored by the Italian Centre for Comparative and Foreign Law Studies and UNIDROIT Contract Principles. The cases are in abstract format, but, when available, the full text of the case in the original language is also supplied.

  • PDF

인공신경망 기법을 이용한 청미천 유역 Flux tower 결측치 보정 (A point-scale gap filling of the flux-tower data using the artificial neural network)

  • 전현호;백종진;이슬찬;최민하
    • 한국수자원학회논문집
    • /
    • 제53권11호
    • /
    • pp.929-938
    • /
    • 2020
  • 본 연구에서는 청미천 유역에서의 플럭스타워에서 산출되는 증발산량의 결측값을 보완하기 위해 인공신경망(Artificial Neural Network, ANN)을 사용하였다. 비교 평가를 위해, Mean Diurnal Variation(MDV), Food and Agriculture Organization Penman-Monteith(FAO-PM) 방법들을 이용하여 증발산량을 산정하였고, ANN 방법을 이용한 결과와 비교하였다. 비교 평가 방법으로 시계열 방법 및 통계 분석(결정계수, IOA, RMSE, MAE)이 사용되었다. 각 gap-filling 모델의 검증을 위해 2015년의 30분 단위 데이터를 이용하였으며, 121개의 결측값 중 MDV, FAO-PM, ANN 방법 순으로 각각 70, 53, 54개의 결측값을 보완하여 모든 데이터가 관측되지 않은 36개의 데이터를 제외하면 각각 82.4%, 62.4%, 63.5%의 성능을 보였다. 결정계수(MDV, FAO-PM, ANN 방법 순으로 각각 0.673, 0.784, 0.841)와 IOA(MDV, FAO-PM, ANN 방법 순으로 각각 0.899, 0.890, 0.951)를 분석한 결과, 3가지 방법 모두 양질의 상관성을 보여 활용성이 충분하다고 판단되며, 이 중 ANN 모델이 가장 높은 적합도와 양질의 성능을 나타내었다. 본 연구를 기반으로 기계학습방법을 이용한 플럭스 타워 자료의 gap-filing 연구에 보다 적절하게 활용될 수 있을 것이다.

가역성을 갖는 무황변 Polyvinyl Butyral 메움제의 개발과 이를 이용한 삼천사지 분청사기접시의 복원 (The Development of the Unfading Polyvinyl Butyral Gap-filling Material Based on Reversible Properties and Restoration of a Punchong Plate from Sam-cheon Temple Site with This Polyvinyl Butyral Product)

  • 한원식;위광철;박기정;홍태기
    • 보존과학회지
    • /
    • 제25권3호
    • /
    • pp.293-298
    • /
    • 2009
  • Polyvinyl butyral (Butvar) 원재와 silane계 첨가제를 iso-propyl alcohol에 용해시킨 도자기 복원용 메움제를 제조하였다. 이는 원하는 정도로 경도의 조절이 가능하고 접착 강도와 전단 강도에서 매우 우수한 결과를 나타내었으며 충진성, 수축성, 도색성 등에서도 일반적으로 사용되는 에폭시계 메움제와 같은 결과들을 나타내고 있었다. 특히, 현재 일반적으로 사용되는 에폭시계 메움제의 문제점인 황변 현상과 복원 가역성을 해결함으로서, 도자기의 복원의 항구성과 지속적인 안정성을 부여할 수 있을 것으로 보인다. 또 본 메움제를 이용하여 삼천사지 분청사기를 복원하였으며 복원 후, 이를 재 용해하여 메움제를 완벽히 제거하는 과정을 통하여 복원의 가역성도 보이고자 하였다.

  • PDF

해양모니터링 자료의 장기결측 보충 기법 (Long-gap Filling Method for the Coastal Monitoring Data)

  • 조홍연;이기섭;이욱재
    • 한국해안·해양공학회논문집
    • /
    • 제33권6호
    • /
    • pp.333-344
    • /
    • 2021
  • 해양모니터링 자료에서 빈번하게 발생하는 장기결측구간의 자료 보충기법을 제안한다. 제안하는 방법은 결측구간의 장기변동 추세 성분과 단기변동 잔차성분을 추정하여 조합하는 방식으로 결측구간의 미지 정보를 추정한다. 이 방법을 이용하여 울릉도 해상부이 자료의 수온 항목, 약 1개월 정도의 장기결측 구간의 자료를 보충하였으며, 부이에서 관측하는 자료 항목에 대해서도 결측 보충을 수행하였다. 보충된 자료는 항목에 따라 차이를 보이지만 변동양상이 적절하게 재현되는 것으로 파악되었다. 이 방법은 추세추정과 잔차 반영에 따른 편향오차와 분산오차가 발생하지만, 장기결측으로 인한 통계적인 측도 추정의 편향오차는 크게 절감하는 것으로 파악되었다. 결측보충 모형의 추정 RMS 오차의 평균과 90% 신뢰구간은 각각 0.93, 0.35~1.95 범위이다.

Effect of Plasma Pretreatment on Superconformal Cu Alloy Gap-Filling of Nano-scale Trenches

  • 문학기;이정훈;이수진;윤재홍;김형준;이내응
    • 한국진공학회:학술대회논문집
    • /
    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
    • /
    • pp.53-53
    • /
    • 2011
  • As the dimension of Cu interconnects has continued to reduce, its resistivity is expected to increase at the nanoscale due to increased surface and grain boundary scattering of electrons. To suppress increase of the resistivity in nanoscale interconnects, alloying Cu with other metal elements such as Al, Mn, and Ag is being considered to increase the mean free path of the drifting electrons. The formation of Al alloy with a slight amount of Cu broadly studied in the past. The study of Cu alloy including a very small Al fraction, by contrast, recently began. The formation of Cu-Al alloy is limited in wet chemical bath and was mainly conducted for fundamental studies by sputtering or evaporation system. However, these deposition methods have a limitation in production environment due to poor step coverage in nanoscale Cu metallization. In this work, gap-filling of Cu-Al alloy was conducted by cyclic MOCVD (metal organic chemical vapor deposition), followed by thermal annealing for alloying, which prevented an unwanted chemical reaction between Cu and Al precursors. To achieve filling the Cu-Al alloy into sub-100nm trench without overhang and void formation, furthermore, hydrogen plasma pretreatment of the trench pattern with Ru barrier layer was conducted in order to suppress of Cu nucleation and growth near the entrance area of the nano-scale trench by minimizing adsorption of metal precursors. As a result, superconformal gap-fill of Cu-Al alloy could be achieved successfully in the high aspect ration nanoscale trenches. Examined morphology, microstructure, chemical composition, and electrical properties of superfilled Cu-Al alloy will be discussed in detail.

  • PDF

휴대용 초음파진단기를 위한 펄스 도플러 갭 필링 알고리즘의 개선 (Improvements of Pulse Doppler Gap Filling Algorithms for Portable Medical Ultrasound Imaging System)

  • 배무호;안형준
    • 한국음향학회지
    • /
    • 제31권8호
    • /
    • pp.580-589
    • /
    • 2012
  • 이 논문에서는 휴대용, 또는 저가형 초음파진단기에 비교적 고급 기능인 도플러 갭 필링 모드를 적용하고자할 때 적합한 알고리즘들을 찾아보았고, 그 결과 미러링 기반, 또는 자기회귀 모델 기반의 알고리즘들을 찾을 수 있었다. 또, 계산량이 지나치게 많아지지 않는 범위 내에서, 그러한 알고리즘들의 성능의 문제점을 보완하여 더욱 개선시켰다. 수정된 알고리즘들은 인공적으로 발생시킨 도플러 신호 및 실제 초음파장비를 써서 인체로부터 획득한 도플러 데이터를 써서 시뮬레이션 및 실험을 함으로써 유효성을 확인하였다.

Flowable oxide CVD Process for Shallow Trench Isolation in Silicon Semiconductor

  • Chung, Sung-Woong;Ahn, Sang-Tae;Sohn, Hyun-Chul;Lee, Sang-Don
    • JSTS:Journal of Semiconductor Technology and Science
    • /
    • 제4권1호
    • /
    • pp.45-51
    • /
    • 2004
  • We have proposed a new shallow trench isolation (STI) process using flowable oxide (F-oxide) chemical vapor deposition (CVD) for DRAM application and it was successfully developed. The combination of F-oxide CVD and HDP CVD is thought to be the superior STI gap-filling process for next generation DRAM fabrication because F-oxide not only improves STI gap-filling capability, but also the reduced local stress by F-oxide in narrow trenches leads to decrease in junction leakage and gate induced drain leakage (GIDL) current. Finally, this process increased data retention time of DRAM compared to HDP STI. However, a serious failure occurred by symphonizing its structural dependency of deposited thickness with poor resistance against HF chemicals. It could be suppressed by reducing the flow time during F-oxide deposition. It was investigated collectively in terms of device yield. In conclusion, the combination of F-oxide and HDP oxide is the very promising technology for STI gap filling process of sub-100nm DRAM technology.

선수파 중 슬로싱을 고려한 병렬배치된 두 부유체의 거동 특성에 관한 실험 연구 (Experimental Study of Motion Behavior of Side-by-Side Moored Two Floating Bodies Including Sloshing in Head Sea)

  • 조석규;성홍근;홍장표;홍사영;홍석원
    • 한국해양공학회지
    • /
    • 제26권6호
    • /
    • pp.46-52
    • /
    • 2012
  • The motions and drift forces of side-by-side moored FSRU and LNGC including the sloshing effect, were studied using experiments. The FSRU and LNGC contained LNG cargo tanks and the LNG sloshing could affect the motions and drift forces of the structures due to its coupling with floating body motion. The effect of coupling can vary with the LNG filling level, and the effect of the filling level was investigated. The coupling effect was stronger at lower filling level. It was confirmed that longitudinal sloshing influenced the surge and surge mean drift force in head sea. In addition, gap flow affected the sway and mean drift forces. Sloshing attenuated the sway and yaw excited by gap flow in side-by-side configuration.

언더필 공정에 대한 유동 특성과 침투 시간 예측 연구 (Flow Characteristics and Filling Time Estimation for Underfill Process)

  • 심형섭;이성혁;김종민;신영의
    • Journal of Welding and Joining
    • /
    • 제25권3호
    • /
    • pp.45-50
    • /
    • 2007
  • The present study is devoted to investigate the transient flow and to estimate the filling time fur underfill process by using the numerical model established on the fluid momentum equation. For optimization of the design and selection of process parameters, this study extensively presents an estimation of the filling time in the view points of some important factors related to underfill materials and flip-chip geometry. From the results, we conclude that the filling time changes with respect to the under fill materials because of different viscosity, surface tension coefficient and contact angle. It reveals that, as the gap height increases, the filling time decreases substantially, and goes to the saturated values.