• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.965-967
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• 2003

Information on forest volume, forest coverage and biomass are important for developing global perspectives about CO$_{2}$ concentration changes. Forest biomass cannot be directly measured from space yet, but remotely sensed greenness can be used to estimate biomass on decadal and longer time scales in regions of distinct seasonality, as in the north. Hence, in this research, numerical methods were used to estimate forest biomass in higher northern regions. A regression model linking Normalized Difference Vegetation Index(NDVI), to forest biomass extracted from SPOT/4 VEGETATION data and PAL 8km data in regional and continental area (N40-N70) respectively. Statistical tests indicated that the regression model can be used to represent the changes of forest biomass carbon pools and sinks at high latitude regions over years 1982-2000. This study suggests that the implementation of estimation of biomass based on 8-km resolution NOAA/AVHRR PAL and SPOT-4/VEGETATION data could be detected over a range of land cover change processes of interest for global biomass change studies.

• 한국안전학회지
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• 제37권6호
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• pp.18-24
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• 2022

Hydrogen is a clean fuel and is used in many applications in power systems such as fuel cells. It has unique properties such as wide flammability, high burning velocity, and difficulty to liquefy, which lead to critical safety issues. Fire and explosion are the most frequently occurring accidents and one of the major reasons is autoignition. In the ignition process, the chemistry of hydrogen combustion depends mainly on radical pools, and the temperature at which chain-branching and terminating rates are equal is called the crossover temperature. This study addresses the homogeneous autoignition of diluted hydrogen-air mixtures to investigate the effects of dilution on the crossover temperature to prevent explosions in the future. The new criterion for crossover temperature is introduced by only hydrogen radicals to adjust more simply. The detailed calculations indicate that the crossover temperatures are low at high dilutions of carbon dioxide and nitrogen because the concentrations of active radicals are reduced when an inert gas is added. This result is expected to contribute to hydrogen safety and realize a hydrogen society in the future.

• 한국산림과학회지
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• 제100권4호
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• pp.591-597
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• 2011

본 연구는 산림탄소계정을 고려한 국유림 장기경영계획 수립 시 의사결정정보를 제공하기 위해, 경영 시나리오에 따른 CBM-CFS3 모델을 적용한 산림탄소축적량의 변화를 예측하였다. 목재생산 수준에 따라 기존 경영계획의 연간 벌채면적(120 ha) 유지(시나리오1), 매분기별 30% 증가(시나리오 2), 현 수준의 3배 증가(시나리오3), 5배 증가(시나리오4) 등의 4가지 경영시나리오를 구성하였고, 100년의 계획기간동안 총 탄소축적량, 탄소저장고별 축적량, 수확된 목제품 탄소량, 영급구조의 변화를 예측하였다. 연구 결과, 기존 벌채수준을 유지하는 시나리오1의 경우 목제품을 포함한 총 탄소축적량이 433.1 tC/ha로 가장 높았으나 계획기간 말 임분구조가 노령림에 편중되는 문제점이 나타났으며, 반면 시나리오4의 경우 계획기간 말 노령림 면적이 크게 줄어들고 총 탄소축적량이 385.5 tC/ha으로 크게 떨어지는 문제점이 있었다. 벌채면적을 매분기 30% 증가시키는 시나리오2와 현 수준의 3배로 증가시키는 시나리오3의 경우, 영급분포가 I~VIII영급에 고르게 분포하고 총 탄소축적량도 각각 411.7 tC/ha, 410.5 tC/ha으로 초기의 산림탄소축적량을 지속적으로 유지하는 것으로 나타나, 산림탄소계정을 고려한 경영계획에 적합한 것으로 판단되었다.

• 한국토양비료학회지
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• 제47권3호
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• pp.191-198
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• 2014

Absorption and accumulation of heavy metals in plants were determined by phytoavailable contents rather than total contents of heavy metals. Therefore, phytoavailability-based management protocol should be prepared for safe food crop production in contaminated agricultural lands. This study was conducted to understand the distribution and phytoavailability of heavy metal in the Korean agricultural soils affected by abandoned mining sites along with investigation of soil properties (soil pH, OM, DOC, clay content, Al/Fe/Mn content) influencing on the metal phytoavailability. For this, 142 agricultural soils located nearby 39 abandoned mining sites distributed in five province in Korea, were analyzed. Among the four different heavy metals, cadmium (Cd) and zinc (Zn) appeared to exist in more phytoavailable form than cupper (Cu) and lead (Pb). Soil pH was the main factor governing phytoavailable Cd, Pb, and Zn showing positive relationship with partitioning coefficients of the corresponding metals; Cd (r = 0.66, P < 0.001), Pb (r = 0.70, P < 0.001), and Zn (r = 0.62, P < 0.001). This implied higher phytoavailability of the corresponding metals with higher soil pH. In contrast, phytoavailability of Cu (r = 0.41, p < 0.01) was only negatively related with soil DOC (dissolved organic carbon).