• 제목/요약/키워드: LST

검색결과 443건 처리시간 0.028초

Spatial Downscaling of MODIS Land Surface Temperature: Recent Research Trends, Challenges, and Future Directions

  • Yoo, Cheolhee;Im, Jungho;Park, Sumin;Cho, Dongjin
    • 대한원격탐사학회지
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    • 제36권4호
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    • pp.609-626
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    • 2020
  • Satellite-based land surface temperature (LST) has been used as one of the major parameters in various climate and environmental models. Especially, Moderate Resolution Imaging Spectroradiometer (MODIS) LST is the most widely used satellite-based LST product due to its spatiotemporal coverage (1 km spatial and sub-daily temporal resolutions) and longevity (> 20 years). However, there is an increasing demand for LST products with finer spatial resolution (e.g., 10-250 m) over regions such as urban areas. Therefore, various methods have been proposed to produce high-resolution MODIS-like LST less than 250 m (e.g., 100 m). The purpose of this review is to provide a comprehensive overview of recent research trends and challenges for the downscaling of MODIS LST. Based on the recent literature survey for the past decade, the downscaling techniques classified into three groups-kernel-driven, fusion-based, and the combination of kernel-driven and fusion-based methods-were reviewed with their pros and cons. Then, five open issues and challenges were discussed: uncertainty in LST retrievals, low thermal contrast, the nonlinearity of LST temporal change, cloud contamination, and model generalization. Future research directions of LST downscaling were finally provided.

Retrieval of emissivity and land surface temperature from MODIS

  • Suh Myoung-Seok;Kang Jeon-Ho;Kim So-Hee;Kwak Chong-Heum
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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    • pp.165-168
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    • 2005
  • In this study, emissivity and land surface temperature (LST) were retrieved using the previously developed algorithms and Aqua/MODIS data. And sensitivity of estimated emissivity and LST to the predefined values, such as land cover, normalized difference vegetation index (NOVI) and spectral emissivity were investigated. The methods used for emissivity and LST were vegetation cover method (VCM) and four different split-window algorithms. The spectral emissivity retrieved by VCM was not sensitive to the NOVI error but more sensitive to the land cover error. The comparison of LST showed that the LST was systematically different without regard to the land cover and season. And the LST was very sensitive to the emissivity error excepting the Uliveri et al. This preliminary result indicates that more works are needed for the retrieval of reliable LST from satellite data.

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MTSAT-1R 자료를 이용한 지표면온도 산출 및 분석 (Retrieval and analysis of LST from MTSAT-1R)

  • 곽서연;서명석;강전호
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2007년도 춘계학술대회 논문집
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    • pp.271-276
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    • 2007
  • 지표면의 파장별 방출율을 알고 있다는 가정하에 대기의 흡수효과가 상이한 두 파장역을 이용하여 대기효과를 보정해주는 일반적인 분리대기창(Generalized Split-Window) 방법으로 MTSAT-1R 자료로부터 지표면 온도(LST) 산출 알고리즘을 개발하였다. 지표면온도 산출 회귀식은 대기복사전달모델 MODTRAN4.0으로 위성으로부터 LST를 산출하는데 영향을 주는 여러 가지 요소(주/야간,수증기, 방출율,위성관측각 등)들을 고려하여 모의된 자료로부터 도출하였다. 개발한 LST 산출알고리즘의 수준을 분석하기 위해 MSGl SEVIRI 센서에 적합하도록 개 발된 Sobrino and Romaguera(2004)의 알고리즘과 GMS-5 VISSR 센서에 적합하도록 개발된 Prata and Cechet(1999)의 알고리즘과 비교하였다. 3 알고리즘을 MTSAT-1R 자료에 적용하여 LST를 산출한 결과 LST의 공간분포는 정성적으로 서로 유사하게 나타났으나,정량적으로는 지리적 위치,계절 및 주간/야간에 따라서 LST가 다르게 나타났다.

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The Influence of Opposing Flow and Its Separation of SBF over Masan on Southeast Coast of the Korea

  • Ji, Hyo-Eun;Lee, Kwi-Ok;Lee, Soon-Hwan;Park, Soon-Young;Jeon, Won-Bae;Lee, Hwa-Woon
    • Asian Journal of Atmospheric Environment
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    • 제5권4호
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    • pp.216-227
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    • 2011
  • A Sea breeze front (SBF) appears clear particularly if there is opposing wind, and the convergence zone along a SBF affects air quality in coastal areas. This study analyzes features of SBF separation in the presence of an opposing flow in the southeastern coastal area of Korea Peninsula. Using a Regional Atmospheric Modeling System (RAMS) numerical simulation and an opposing flow, two types of SBF were observed at Masan coastal area of Korea. In one, the SBF penetrated inland despite of the opposing flow at Jinhae (1100 LST), Wondong (1700 LST), Saenglim (1700 LST), and Miryang (1700 LST). In the other, the SBF remained on the coastline along with Jinhae (1100 LST), Masan (1400 LST), Jinbuk (1400 LST), and Gaecheon (1700 LST), because the inflow of the sea breeze was not sufficient to penetrate inland against the opposing flow. This study shows that SBFs are affected by the formation of an opposing flow, as well as the inflows of a sea breeze and the opposing flow.

한반도에서의 천리안 위성 지표면 온도 유용성 평가 (Availability of Land Surface Temperature from the COMS in the Korea Peninsula)

  • 백종진;최민하
    • 한국수자원학회논문집
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    • 제45권8호
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    • pp.755-765
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    • 2012
  • 지표면 온도는 수문기상학에서 매우 중요한 인자로써 지면-대기의 상호순환을 이해하는 데 필수적인 요소이다. 따라서 지표면 온도를 정확하게 산출하기 위한 연구가 이루어지고 있다. 그러나 국내에서는 현재까지 시 공간적으로 일정한 자료를 대상으로 한 연구가 미흡한 상황이다. 본 연구에서는 국내 최초의 정지궤도 위성인 Communication, Ocean and Meteorological Satellite (COMS)의 지표면 온도 자료를 사용하여 MODerate-resolution Imaging Spectroradiometer (MODIS) 센서를 탑재한 위성(Terra/Aqua)에서 제공되는 지표면 온도와 비교 분석을 실시하였다. 또한, COMS 자료의 정확성 확인을 위하여 지상관측지점의 자료와 비교하였다. 그 결과 MODIS와의 비교에서는 COMS가 Aqua/Terra에 비하여 전체적으로 과소 산정되었으며, Aqua보다는 Terra와 비슷한 경향을 가지고 있는 것을 확인할 수 있었다. 지상 관측 일평균자료와의 비교에서도 COMS가 과소 산정되는 것으로 나타났다. 각각의 오차는 알고리즘 사용 인자의 차이, 자료의 시간적 차이, 외부적인 요인 등으로 인해 발생하는 것으로 판단된다. 그러나 전체적인 경향성이 비슷한 것으로 나타나 COMS의 활용 가능성을 확인할 수 있었으며, 추후보다 정확한 검 보정에 대한 연구가 필요한 실정이다.

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

  • Choi, Sungwon;Lee, Kyeong-Sang;Seo, Minji;Seong, Noh-Hun;Jin, Donghyun;Jung, Daeseong;Sim, Suyoung;Jung, Im Gook;Han, Kyung-Soo
    • 대한원격탐사학회지
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    • 제37권1호
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    • pp.153-160
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    • 2021
  • 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.

연명치료 중단의 입법화 방안에 관한 연구 - 성년후견제도의 도입과 관련하여 - (A Study on the Method of Legislation on Withholding or Withdrawing of LST -In relation to the introduction of adult guardianship-)

  • 이은영
    • 의료법학
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    • 제10권2호
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    • pp.203-249
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    • 2009
  • It is the so-called Shinchon Severance Hospital Case brought to an end by the decision of the Supreme Court that opened the real discourse of withholding or withdrawing of LST (Life-Sustaining Treatment) in the legal profession as well as medical profession in Korea. Everyone has sympathy with the validity and necessity of legal regulation on withdrawing-including withholding-of LST save the requirements & procedure of withdrawing of LST. In this situation, the legislative bill of amendment to the Korean Civil Law introducing of adult guardianship was pre-announced by the Ministry of Justice on September 18th 2009. The adult guardianship is a guardianship system that supports an mentally handicapped adult to deal with his affairs by support of a guardian. The object of adult guardianship includes affairs of body or well-being as well as property of adult wards. In particular, affairs of medical matters are of importance in the duty and authority of adult guardians. So, the introduction of adult guardianship is of much importance de lege lata as well as de lege ferena in the discussion of withdrawing of LST as a medical treatment. Since the legislation on withdrawing of LST intents to protect the right of death with dignity on the basis of patients' autonomy, the ratio legis of withdrawing of LST is variant from that of adult guardianship. In this context, it seems reasonable to legislate the withdrawing of LST separately from the adultguardianship. In the meantime, the adult guardianship of the legislative bill of amendment to the Korean Civil Law is related to the withdrawing of LST, since the main purpose of adult guardianship is to protect patients' quality of lives and to regulate guardianship contracts based on patients' autonomy. In that context, it seems reasonable to incorporate the legislation of withdrawing of LST into the adult guardianship system. In the latter case, it is not easy to adopt the withdrawing of LST into the legislative bill of the Korean Civil Law for the bill is pre-announced already as previously stated. However, the legislation of withdrawing of LST is not inferior to the legislation of adult guardianship as a matter of urgency. Moreover, it is likely that the legislative bill of Amendment to the Korean Civil Law generates discrepancies in interpretation of the requirements & procedure of withdrawing of LST as the amended German Civil Law did. In short, it is desirable for the legislator to revise the legislative bill despite delay.

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Participation and Influencing Factors in the Decision-Making of Life-Sustaining Treatment: A Focus on Deceased Patients with Hematologic Neoplasms

  • Jae Eun Jang;Jeong Moon Ryu;Min Hee Heo;Do Eun Kwon;Ji Yeon Seo;Dong Yeon Kim
    • Journal of Hospice and Palliative Care
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    • 제26권2호
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    • pp.69-79
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    • 2023
  • Purpose: This study aimed to investigate the involvement of patients who died from hematologic neoplasms in the decision-making process surrounding the withdrawal of life-sustaining treatment (LST). Methods: A total of 255 patients diagnosed with hematologic neoplasms who ultimately died following decisions related to LST during their end-of-life period at a university hospital were included in the study. Data were retrospectively obtained from electronic medical records and analyzed utilizing the chi-square test, independent t-test, and logistic regression. Results: In total, 42.0% of patients participated in the decision-making process regarding LST for their hematologic neoplasms, while 58.0% of decisions were made with family involvement. Among these patients, 65.1% died in general wards and 34.9% in intensive care units (ICUs) as a result of decisions such as the suspension of LST. The period from the LST decision to death was longer when the decision was made by the patient (average, 27.15 days) than when it was made by the family (average, 7.48 days). Most decisions were made by doctors and family members in the ICU, where only 20.6% of patients exercised their right to make decisions regarding LST, a rate considerably lower than 79.4% observed in general wards. Decisions to withhold or withdraw LST were more commonly made by patients themselves than by their families. Conclusion: The key to discussing the decision to suspend hospice care and LST is respecting the patient's self-determination. If a patient is lucid prior to admission to the ICU, considerations about suspending LST should involve the patient input.

Study on seismic response of a seismic isolation liquid storage tank

  • Xiang Li;Jiangang Sun;Lei Xu;Shujin Zhang;Lifu Cui;Qinggao Zhang;Lijie Zhu
    • Earthquakes and Structures
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    • 제26권5호
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    • pp.337-348
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    • 2024
  • This paper presents a new seismic isolation design for liquid storage tank (LST). The seismic isolation system includes: LST, flexible membrane, sand mat and rolling seismic isolation devices. Based on the mechanical equilibrium theory, the symmetric concave rolling restoring force model of the isolation device is derived. Based on the elasticity theory and restoring force model of the seismic isolation, a simplified mechanical model of LST with the new seismic isolation is established. The rationality of the seismic isolation design of LST is explored. Meanwhile, the seismic response of the new seismic isolation LST is investigated by numerical simulation. The results show that the new seismic isolation tank can effectively reduce the seismic response, especially the control of base shear and overturning moment, which greatly reduces the risk of seismic damage. The seismic reduction rate of the new seismic isolation storage tanks in Class I, II, and III sites is better than that in Class IV sites. Moreover, the seismic isolation device can effectively control the ground vibration response of storage tanks with different liquid heights. The new seismic isolation LST design provides better isolation for slender LSTs than for broad LSTs.

고해상도 Landsat 8 위성자료기반의 지표면 온도 산출 (Retrieval of Land SurfaceTemperature based on High Resolution Landsat 8 Satellite Data)

  • 지준범;김부요;조일성;이규태;최영진
    • 대한원격탐사학회지
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    • 제32권2호
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    • pp.171-183
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    • 2016
  • 2013년부터 2014년까지 관측된 Landsat 8 위성자료로부터 지표면 온도를 산출하였고 산출된 지표면 온도는 지상에서 관측된 지표면 온도를 이용하여 보정하였다. 지표면 온도지도는 Landsat 8로부터 산출된 지표면 온도를 지상에서 관측된 지표면 온도와의 선형 회귀식을 이용하여 계산되었다. 계절과 년에 대한 지표면 온도는 각각 계절과 년에 대하여 사례들을 평균하여 계산되었다. 지표면 온도는 도시의 공업 또는 상업지역에서 높은 온도가 나타나는 반면, 서울주변의 높은 고도의 산악과 해양, 강 등에서 낮은 지표면 온도가 나타났다. 위성에서 산출된 지표면 온도를 보정하기 위하여 서울을 포함한 수도권지역에서 관측되는 기상청 종관측소 3개 지점 (서울(지점번호: 108), 인천(지점번호: 119), 수원(지점번호: 112))의 지표면 관측 자료를 이용하여 선형회귀방법을 적용하였다. Landsat 8의 지표면 온도는 모든 자료에서 기울기가 0.78이었고 5개의 흐린날을 제외한 맑은 상태의 자료에서 0.88이었다. 그리고 초기 지표면온도에서 상관계수는 0.88이었고 평방근 오차 (Root Mean Sqare Error (RMSE))는 $5.33^{\circ}C$이었다. 지표면 온도 보정이후에는 상관계수는 0.98 그리고 RMSE는 $2.34^{\circ}C$이었으며 회귀식의 기울기는 0.95로 개선되었다. 계절 및 년 지표면 온도는 상업지역과 공업지역 그리고 도시와 주변지역을 잘 표현하였다. 결과적으로 지상에서 관측된 지표면 온도를 이용하여 위성에서 산출된 지표면온도를 보정하였을 때 실제 상태와 유사한 분포를 보였다.