• Journal of Korean Society of Forest Science
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• v.75 no.1
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• pp.51-54
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• 1986

The good growth of Populus alba ${\times}$ P. glandulosa is shown at the foothill of the mountain where good soil moisture is available, but its growth is poor at the upper part of the mountain where soil moisture is limitted. Stomatal frequency, stomatal size and transpiration rates that affect soil moisture demand were determined in order to know how this character is inherited from its parents. Number of stomata per $mm^2$, length and width of stomata from the abaxial leaf and transpiration rate ($g/cm^2$) per day in P. alba ${\times}$ P. glandulosa showed intermediate values between those of their parents, while P. alba showed the highest values and P. davidiana the lowest values. The values of stomatal frequency of P. alba ${\times}$ P. glandulosa were close to the expected mean values of parents in the $x^2$ test, and in the regression analysis the transpiration rates for the hybrid and its midparent had strong relationship with 0.97 of regression coefficient. The fact that these intermediate characteristics were observed in the hybrid suggests incomplete dominance in the hybrid. It is concluded that soil moisture demand in P. alba ${\times}$ P. glandulosa and its parents is closed related to stomatal frequency, stomatal size and transpiration rate.

• The Korean Journal of Nuclear Medicine
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• v.34 no.1
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• pp.74-81
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• 2000

Purpose: The purpose of this study was to develop in vivo dosimetries using both chromosomal aberrations and micronuclei in mice to assess biological effects of radiations. Materials and Methods: Five each mice were irradiated with 0, 1, 2, 3, 4, 5, 10 Gy of Cs-137 gamma-rays. We scored numbers of chromosomal aberrations in metaphase spreads and numbers of micronuclei in bone marrow smears under light microscope, and obtained the dose-response relationships. We also examined the relationship between the two dose-response curves. Results: The frequency of both chromosomal aberrations and micronuclei increased with dose, in a linear-quadratic manner The delta, beta, and alpha coefficients were 0.0176, 0.0324, and 0.0567 for metaphase analysis (r=1.0, p<0.001) and 0.0019, 0.0073, and 0.0506 for micronuclei assay (r=1.0, p<0.001). The frequency of chromosomal aberrations and micronuclei in different radiation doses was significantly correlated (r=0.99, p<0.01). Conclusion: In vivo dosimetry using either metaphase analysis or micronucleus assay was feasible in mice. These methods could be useful to evaluate biological effects of radiation.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.167-167
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• 2016

일반적으로 빈도해석은 강우의 연 최대 강우자료들을 통해 지속기간별 확률강우량을 산정한다. 하지만 강우자료들은 관측기간이 상대적으로 짧은 편이라 지점 별 강우특성을 고려한 확률강우량 산정은 쉽지 않다. 각 지점 별 강우특성을 고려하기 위해서 연속적인 시계열로 기록되어 있는 강우자료를 독립 강우사상으로 분리하여 강우사상간의 시간, 즉, 무강우시간을 결정하는 것이 선행되어야 한다. 연속강우자료를 독립 강우사상으로 분리하기 위해서는 강우사상 간의 기준이 필요하다. 기존의 연구에서는 강우사상을 분리하기 위한 기준으로 무강우시간(Inter-Event Time, IET)을 사용하고 있다. 국내의 경우에는 무강우시간을 10시간부터 12시간까지 다양하게 적용하고 있다. 따라서 본 연구에서는 기상청 산하 강우관측소의 우기(4월~10월) 자료를 이용하여 시간 단위를 각각 1분, 5분 그리고 1시간으로 분리하였다. 강우분리방법은 자기상관계수와 포아송분포(Poisson distribution)를 고려한 지수분포(exponential distribution)의 변동계수를 이용하여 무강우시간 결정 방법(Inter-Event Time Definition, IETD)을 적용하였다. 각 지점별로 추출된 1분, 5분 그리고 1시간의 무강우시간을 비교 및 분석하였고, 이를 통해 각 지점의 시간단위 특성에 의한 적절한 무강우시간 및 강우사상시간을 제시할 수 있을 것으로 판단된다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.5
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• pp.617-626
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• 2022

In Korea, annual precipitation and its variability have gradually increased since modern meteorological observations began, and the risk of disasters has also been increasing due to significant regional variations and recent abnormal climate conditions. Given that damage from storms and floods mainly occurs around rivers, it is crucial to determine the appropriate design frequency for river-related projects. This study examined existing design practices used to determine hydrological design frequencies and suggested a new method to determine appropriate design frequencies. The study collected available data pertaining to seven evaluation factors, specifically the basin areas, shape parameters, channel slopes, stream orders, backwater effect reaches, extreme rainfall frequencies, and urbanized flood inundation areasfor 413 local rivers in Chungcheongnam-do in Korea. The estimated weights for areas of extreme rainfall frequencies and urbanized flood inundation were found to be 18, having a great effect on determining the design frequency. Compared with the established design frequency in previous government reports, the estimated design frequency increased for 255 rivers and decreased for 158 rivers.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5B
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• pp.489-499
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• 2006

The Potential Flood Damage (PFD) is widely used for representing the degree of potential of flood damage. However, this cannot be related with the design frequency of river basin and so we have difficulty in the use of water resources field. Therefore, in this study, the concept of Potential Risk for Flood Damage Occurrence (PRFD) was introduced and estimated, which can be related to the design frequency. The PRFD has three important elements of hazard, exposure, and vulnerability. The hazard means a probability of occurrence of flood event, the exposure represents the degree that the property is exposed in the flood hazard, and the vulnerability represents the degree of weakness of the measures for flood prevention. Those elements were devided into some sub-elements. The hazard is explained by the frequency based rainfall, the exposure has two sub-elements which are population density and official land price, and the vulnerability has two sub-elements which are undevelopedness index and ability of flood defence. Each sub-elements are estimated and the estimated values are rearranged in the range of 0 to 100. The Analytic Hierarchy Process (AHP) is also applied to determine weighting coefficients in the equation of PRFD. The PRFD for the Anyang river basin and the design frequency are estimated by using the maximum rainfall. The existing design frequency for Anyang river basin is in the range of 50 to 200. And the design frequency estimation result of PRFD of this study is in the range of 110 to 130. Therefore, the developed method for the estimation of PRFD and the design frequency for the administrative districts are used and the method for the watershed and the river channel are to be applied in the future study.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5B
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• pp.515-524
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• 2008

An estimation of reliable probability precipitation is one of the most important processes for reasonable hydrologic structure design. A probability precipitation has been calculated by frequency analysis using annual maximum rainfall series on the each duration among the observed rainfall data. Annual maximum rainfall series have abstracted on hourly rainfall data or daily rainfall data. So, there is necessary to proper conversion factor between the fixed and sliding durations. Therefore, in this study, conversion factors on the each duration between fixed and sliding durations have calculated using minutely data compared to hourly and daily data of 37 stations observed by Meteorological Administration in Korea. Also, regression equations were computed by regression analysis of conversion factors on the each duration. Consequently, conversion factors were used basis data for calculations of stable probability precipitation.

• Journal of Korean Library and Information Science Society
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• v.51 no.2
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• pp.273-294
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• 2020

The purpose of this study is to provide an in-depth analysis on the publication patterns of the 1,029 journal articles by the Life Sciences' faculty at the K University, for the years 2004-2017 and to investigate any difference between their publication patterns and the citedness for the years 2004-2018. Among the three funding agency types, the research publications supported by foreign funding received the more citations than publications by other types of funding, and the study also found a statistical difference in the citedness (F = 10.467, p < .000***). In addition, the internationally co-authored publications received more citations than three other types of co-authored publications in terms of the immediacy index per publication and the average citations per publication.

• Journal of the Korean Data and Information Science Society
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• v.22 no.6
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• pp.1113-1121
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• 2011

Recently, a variety of data mining techniques has been applied in various fields like healthcare, insurance, and internet shopping mall. Association rule mining is a popular and well researched method for discovering interesting relations among large set of data items. Association rule mining is the method to quantify the relationship between each set of items in very huge database based on the association thresholds. There are three primary quality measures for association rules; support and confidence and lift. In this paper we consider some similarity measures with negative co-occurrence frequencies which is widely used in cluster analysis or multi-dimensional analysis as association thresholds. The comparative studies with support, confidence and some similarity measures are shown by numerical example.

• Journal of Korea Water Resources Association
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• v.55 no.9
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• pp.701-705
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• 2022

Reliable drought inflow scenarios are required to plan reservoirs in response to the present severe drought-like conditions. However, the previously developed method for generating drought inflows, the K-water cumulative difference method (KCM), is considered inadequate owing to its potential for negative inflow, reversal phenomena, and overestimation. Nevertheless, the occurrence of these aspects has not been theoretically analyzed. Hence, this study employed the quantile function and frequency factor for log-normal and Gumbel distributions to quantify the contributing factors of these limitations. Consequently, it was found that the negative inflows are generated when the difference in the location parameters, during the accumulation process, exceeds that of the scale parameters. In addition, as the standard deviation decrease during the accumulation process, the reversal phenomena, and inflated values prevailed.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.51-51
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• 2023

최근 기후의 급격한 변화 및 이상기후로 인해 전 세계적으로 가뭄의 발생빈도가 증가하고 있는 추세이다. 우리나라의 경우 지역·계절별 강수량의 편차로 인해 국지적으로 극심한 가뭄이 발생하고 있으며, 향후 피해는 더욱 증가할 것으로 예측하고 있다. 농업가뭄은 농작물 생육에 따른 수확량 및 수자원 이용에 직접적인 영향을 미치고 있으며, 농업수리시설물의 의존도가 높기 때문에 저수지의 대응능력과 농경지의 수리답 시설이 농업가뭄 대응을 위한 중요한 지표로써 활용되고 있다. 본 연구에서는 수리시설물의 가뭄대응능력과 평야부 농경지의 가뭄빈도를 이용하여 농업가뭄 취약성 평가를 수행하였다. 2015년 이후 매년 가뭄이 발생하는 충청남도 태안군을 시범지역으로 선정하였으며, 논 중심의 농업가뭄을 평가하기 위해 기상영향, 가뭄발생현황, 보조수원능력, 가뭄대응능력 4가지의 관련 항목을 선정하였다. 기상영향, 가뭄발생현황, 보조수원현황 항목은 계수화를 위해 데이터 속성 정보만을 이용하여 가중치를 산정하는 엔트로피 (Entropy) 방법을 적용하였으며, 가뭄대응능력 항목은 농업수리시설물과 농경지 평균 가뭄빈도 분석을 통해 점수화를 수행하였다. 본 연구의 결과는 지역별로 선제적인 가뭄대응 우선순위를 결정할 수 있고, 용수공급의 효율화 등 논 중심의 농업가뭄 대응을 위한 기초자료로써 활용될 수 있을 것으로 판단된다.