• 생약학회지
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• 제7권4호
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• pp.247-250
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• 1976

Phytochemical survey has been made of the occurrence of alkaloids, saponins, terpenoids and flavonoids in 43 Saudi Arabian plants. The result is presented in Table I.

• Archives of Pharmacal Research
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• 제5권1호
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• pp.13-15
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• 1982

Quercetin-3-O-${\beta}$-D glucofuranoside, mp 243-$6^{\circ}$, was isolate dfrom leaves of Polygonum sachalinense Fr. Schm and characterized on the basis of its spectral data. This is the second report of its occurrence in nature.

• 생약학회지
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• 제10권2호
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• pp.83-84
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• 1979

Caffeic aldehyde was isolated from the seeds of Phytolacca americana. This is the first reported occurrence of the compound in nature.

• 약학회지
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• 제17권3호
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• pp.161-166
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• 1973

A glucoside mixture of ${\alpha}$-spinasterol and ${\delta}^7$-stigmastenol was isoated from the roots of Phytolacca esculenta $_{VAN}$ H$_{OUTTE}4. This the first reported occurrence of these glucosides in Phytolaccaceae family.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.166-166
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• 2023

Compound hazards (CHs) are two or more extreme climate events combined which occur simultaneously in the same region at the same time. Compared to individual hazards, the combination of hazards that cause CHs can result in greater economic losses and deaths. While several extreme climate events have been recorded across Asia for the past decades, many studies have only focused on a single hazard. In this study, we assess the spatiotemporal pattern of dry compound hazards which includes drought, heatwave, fire and wind across Asia for the last 42 years (1980-2021) using the historical data from ERA5 Reanalysis dataset. We utilize a daily spatial data of each climate event to assess the occurrence of such compound hazards on a daily basis. Heatwave, fire and wind hazard occurrences are analyzed using daily percentile-based thresholds while a pre-defined threshold for SPI is applied for drought occurrence. Then, the occurrence of each type of compound hazard is taken from overlapping the map of daily occurrences of a single hazard. Lastly, a multivariate assessment are conducted to quantify the occurrence frequency, hotspots and trends of each type of compound hazard across Asia. By conducting a multivariate analysis of the occurrence of these compound hazards, we identify the relationships and interactions in dry compound hazards including droughts, heatwaves, fires, and winds, ultimately leading to better-informed decisions and strategies in the natural risk management.

• Animal Systematics, Evolution and Diversity
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• 제31권3호
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• pp.176-181
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• 2015

Biodiversity is plummeting worldwide, and the major causes of such decline include habitat degradation and climate change. While cities do contribute to the negative impact to the environment, they can also serve as strategic centres for conservation programs. Sites qualifying as biogeographic islands within metropolitan Seoul were studied for the occurrence of two hylid species: the endangered Hyla suweonensis and the abundant H. japonica. This study demonstrates that neither habitat diversity nor surface area, but solely the occurrence of aggregated rice paddies is a requisite for H. suweonensis, hypothetically due to its strict breeding requirements. On the contrary, H. japonica occurrence was not affected by any of these factors, and all types of habitats studied were adequate for this species. The presence of an endangered species within the boundaries of one of the most populated metropolises suggests a strong natural resilience, which should be enhanced with appropriate actions. We emphasize that the management plans therein can, and should, be used as the first step in the conservation of H. suweonensis in metropolitan Seoul.

• International Journal of Contents
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• 제14권3호
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• pp.53-60
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• 2018

Based on the previous studies on sinkholes and ground subsidence conducted until date, the factors affecting the occurrence of sinkholes can be divided into natural environmental factors and human environmental factors in accordance with the purpose of the study. Furthermore, to be more specific, the human environment can be classified into the artificial type and the social type. In this study, the assessment indices for assessing risks of sinkholes and ground subsidence were developed by performing AHP analysis based on the results of the study by Lee et al. (2016), who selected the risk factors for the occurrence of sinkholes by performing Delphi analysis targeting relevant experts. Analysis showed that the artificial environmental factors were of significance in affecting the occurrence of sinkholes. Explicitly, the underground factors were found to be of importance in the natural environment, and among them, the level of underground water turned out to be an imperative influencing factor. In the artificial environment, the underground and subterranean structures exhibited similar importance, and in the underground structures, the excessive use of the underground space was found to be an important influencing factor. In the subterranean ones, the level of water leakage and the erosion of the water supply and sewage piping system were the influential factors, and in the surface, compaction failure was observed as an imperative factor. In the social environment, the regional development, and above all, the groundwater overuse were found to be important factors. In the managemental and institutional environment, the improper construction management proved to be the most important influencing factor.

• 한국산학기술학회논문지
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• 제19권5호
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• pp.611-617
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• 2018

대형구조물의 효과적인 구조 안전성 확보를 위해서는 결함탐지기술을 포함한 건전성 모니터링의 적용이 필요하다. 본 연구에서는 보 구조물에 발생하는 균열위치와 균열크기를 추정하기 위하여 다음과 같은 2단계의 균열추정방법을 제안한다. 우선, 보 구조물의 분포 국부 변형률 계측결과를 이용하여 변형률 모드형상을 구하고, 이에 대한 수정 라플라시안(Laplacian) 연산을 통하여 균열발생 영역을 추정한다. 이후, 가속도 측정을 통하여 구한 고유주파수와 신경망기법을 이용하여, 미리 추정된 균열발생 영역을 대상으로 균열위치와 균열크기를 추정한다. 이때, 신경망을 훈련시키기 위하여, 에너지법에 의해 유도된 균열보의 등가휨강성을 이용하여 균열보의 고유주파수를 해석적으로 구한다. 기법을 검증하기 위하여 알루미늄 캔틸레버 보에 대한 손상실험을 수행하였다. 인위적으로 실험체에 균열을 가한 후 자유진동실험을 수행하여 동적 변형률과 가속도를 계측하고 이를 이용하여 변형률 모드형상과 고유주파수를 구하였다. 변형률 모드형상에 대한 수정 라플라시안 연산을 통하여 균열발생 영역을 추정하고, 고유주파수와 신경망기법을 이용하여, 미리 추정된 균열발생 영역에 대하여 균열위치와 균열크기를 판정하였다. 3가지 손상경우에 대한 균열발생 영역의 추정결과는 실제 영역과 잘 일치하였으며, 균열위치와 균열크기 추정결과의 정확성을 상당히 향상시킬 수 있었다. 제안된 기법은 장대구조물에 대한 구조물 건전성 모니터링에 효과적으로 활용될 수 있을 것으로 판단된다.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2007년도 정기총회 및 학술발표대회
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• pp.315-318
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• 2007

In order to reduce the amount of damage from natural disasters, we needs prevention meteorological database classified into the cause of disaster, damage elements etc. For this, we have analyzed four data, such as Statistical yearbook of calamities issued by the National Emergency Management Agency and Annual Climatological Report issued by the Korea Meteorological Administration and Recently 10 years for natural disaster damage and Statistics Yearbook from the Ministry of Government Administration and Human affairs. Through the analysis of disaster data, we have selected input variables, such as causes and elements, occurrence frequencies, vulnerable areas of natural disaster, etc. In order to reduce damage from natural disaster, the prevention activities and forecasting based on meteorological parameters and damage datas are required. In addition, it is necessary to process meteorological information for disaster prevention activities. Through these procedure, we have established the foundation of database about natural disasters. This database will be used to assess the natural disasters and build risk model and natural disasters mitigation plan.

• 아시안잔디학회지
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• 제10권3호
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• pp.231-246
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• 1996

In order to elucidate the human impact on the distribution of cellular slime molds, samples were collected from 3 types of forest ; natural forests(Mt. Deogyu and Mt. Tsukuba), semi-natural forests(Seoul Great Zoo and Tama Zoo), artificial forests(Seoul National University and Tokyo Gakugei University) .The distribution of cellular slime molds in mountains was different from that of zoo and universities. In mountains, endemic species was occurred and species diversity was higher than in zoo and universities. In zoo and universities disturbed by human, Dictyostelium sphaerocephalum was occurred with higher importance value than in mountains. 6 species were selected to investigate the effect of temperature on froctification; Polysphondylium canlidum, D. delicatum. D. firmibasis, D. sphaerocephalum P. violaceum, D. purpureum. P. violaceum and D. purpureum had an optimum temperature for fructification around 25~3O˚C but the others around 22~23˚C. The degree of sensitivity to temperature was as follows; P. candidum >D. lelicatum > D. firmibasis > D. sphaerocephalum > P. violaceum > D. purpureum. Key words: Human impact, Cellular slime molds, Occurrence and distribution, fructification, Dictylostelium delicatum. Dictyostelium sphaerocephalum.