• 한국지하수토양환경학회지:지하수토양환경
• /
• 제21권3호
• /
• pp.21-34
• /
• 2016

In the present study, we applied various machine learning techniques comparatively for prediction of subsurface structures based on multiple secondary information (i.e., well-logging data). The machine learning techniques employed in this study are Naive Bayes classification (NB), artificial neural network (ANN), support vector machine (SVM) and logistic regression classification (LR). As an alternative model, conventional hidden Markov model (HMM) and modified hidden Markov model (mHMM) are used where additional information of transition probability between primary properties is incorporated in the predictions. In the comparisons, 16 boreholes consisted with four different materials are synthesized, which show directional non-stationarity in upward and downward directions. Futhermore, two types of the secondary information that is statistically related to each material are generated. From the comparative analysis with various case studies, the accuracies of the techniques become degenerated with inclusion of additive errors and small amount of the training data. For HMM predictions, the conventional HMM shows the similar accuracies with the models that does not relies on transition probability. However, the mHMM consistently shows the highest prediction accuracy among the test cases, which can be attributed to the consideration of geological nature in the training of the model.

• The Korean Journal of Ecology
• /
• 제23권6호
• /
• pp.453-460
• /
• 2000

The forest vegetation of Mt. seondal was classified into eight communities and one afforestation by the phytosocialogical method (Z-M method). In general, Quercus mongolica trees occupied most of the area, while afforestation forest was distributed on the lower slope, cultivated land, and at the vicinity of village. The vegetation on the top part of Mt. Seondal was comparatively well preserved, but that in the lower areas has been disturbed heavily by human activity and some had mixed forests composed of pine trees, oaks, ashes, and Rhododendron micrantum shrub. By cluster analysis method. nine groups were identified as follows : Quercus mongolica group, Q. mongolica - Pinus densiflora group, Q. mongolica - Rhododendron schlipen - bachii group, Q. mongolica - Symplocos chinensis for. pilosa group, P. densiflora group, Juglans mandshurica group, Fraxinus mandshurica group, Betula costata group and Larix leptolepis group. These groups showed differences in species composition, but Quercus mongolica, Q. mongolica - P. densiflora, Q. mongolica - R. schlippenbachii and Q. mongolica - S. chinensis for. pilosa groups among them showed very similar floristic composition to each other. In the relationship between polar ordination axes and environmental variables, altitude was the environmental factor determining variation in species composition along axis X and soil moisture was the environmental along axis Y. They were the main factors in determining forest vegetation. The result of cluster analysis and polar ordination for the forest vegetation were corresponded to those of phytosocialogical classification in classifying vegetation.

• 한국조경학회지
• /
• 제27권2호
• /
• pp.58-68
• /
• 1999

This study was carried out to verify the distribution patterns of Salix gracilistyla and Phragmites japonica communities known as obligatory riparian species according to physical factors such as micro-landforms, substrates, etc., at Soo-ip stream corridor. Firstly four vegetation types - Salix gracilistyla dominant type, Phragmites japonica dominant type, mixed type of two species, and mixed type of two species to other species, were classified by cluster analysis based on UPGMA-Euclidean distance. Also these vegetation types showed many different distribution patterns in response to the longitudinal and lateral view along the stream corridor and substrate composition. Salix gracilistyla was major component of dominant vegetation types developed at attack point of bending reach and on substrates composed of rock fragments, but contrastly Phragmites japonica was most important component of dominant vegetation types at point bar of bending reach and floodplain, and on substrates composed of soil materials. Secondly the species and environment biplot form CCA strongly supported the vegetation types divided by classification. Namely Salix gracilistyla was closely correlated with rock fragments and steep slope, which is resistant to physical action even though located near running water. But Phragmites japonica showed a high correlation with soil particles sedimented at floodplain by divergent flow.

• 한국농공학회지
• /
• 제43권4호
• /
• pp.37-49
• /
• 2001

This study was performed in order to produce the basic data for developing prediction techniques of desalinization to be applicable to reclaimed tidal lands at the beginning stage. the desalinization experiments were carried out by two water management practices, namely, the leaching method by subsurface drainage and the rinsing method by surface drainage. The 5 soil samples used in this study were collected in 4 tidal land reclamation projects. Regression equations were obtained in order to investigate the changes of electrical conductivity during the desalinization of reclaimed tidal lands and to estimate water requirements for desalinization. The results obtained from this study were summarized as follows: 1. According to USDA Salinity Laboratory classification system of salt affected soils the reclaimed tidal land soils used in this study were saline-sodic soils with the high electrical conductivity and the high exchangeable sodium percentage. 2. With the increase of the water requirements for desalinization the electrical conductivity was decreased with high degree of correlationships and the desalinization effects were remakable in both the leaching method and the rinsing method. 3. In case of the leaching method the electrical conductivity had been reduced below the classification value of salt affected soils when the depth o water leached per unit depth of soil (Dwl/Ds) was 0.3 and the desalinization effects showed a tendency to be much the same in each treatment.

• 한국화재소방학회논문지
• /
• 제19권3호
• /
• pp.64-69
• /
• 2005

산불은 경제적 손실뿐만 아니라 인명을 위협할 수 있는 국가적 재해다. 이러한 산불을 미연에 방지하고 피해를 저감하기 위해서는 산불발생위험지역을 사전에 판단하여 효율적으로 관리하는 것이 필요하다. 본 연구에서는 입지환경에서 중요한 부분을 차지하는 산림토양특성 중 토양형, 지형, 토성, 경사, 배수 등과 산불발생지점을 가지고 각 지점별 산불발생위험을 예측할 수 있는 산불발생확률 모형을 개발하였다. 개발 시 조건부확률과 GIS를 이용하였다 개발된 산불발생확률 모형의 적합성 검정을 위하여 추정모형의 예측력 비율을 검토할 수 있는 예측비곡선에 적용한 결과 실효성이 있는 것으로 나타났다. 이러한 결과를 적용하여 산불관리자가 손쉽게 산불발생위험지역을 파악할 수 있도록 위험지역을 구분하였다.

• Mycobiology
• /
• 제43권4호
• /
• pp.392-401
• /
• 2015

Using dilution plating method, 47 fungal isolates were obtained from a soil sample collected from Dokdo in the East Sea of Korea in 2013. In this study, two fungal isolates, EML-MFS30-1 and EML-DDSF4, were confirmed as undescribed species, Metarhizium guizhouense and Mortierella oligospora in Korea based on current classification system using multi loci including rDNA internal transcribed spacer, large subunit, small subunit, and ${\beta}$-tubulin (BTUB) genes. Herein, detailed morphological descriptions on characters of the undescribed fungal species as well as their molecular phylogenetic status are provided with comparisons to related species.

• 한국토양비료학회지
• /
• 제42권5호
• /
• pp.385-392
• /
• 2009

대표적인 흑색 화산회토인 남원통은 Ap, BA 및 Bw층에서 Oxalate 침출성 (Al + 1/2 Fe) 함량이 각각 5.2%, 7.4%, 9.8%로 높고 인산보유능이 각각 85.4%, 98.4% 98.3%로 매우 높다. 용적밀도가 각각 $0.72,\;0.62,\;0.76Mg\;m^{-3}$으로 매우 낮다. 전 토층이 Andic 토양 특성을 보유하고 있어서 Andisols로 분류 된다. Udic 토양수분상을 보유하고 있으며, 토양수분 장력 1,500 kPa에서의 토양수분함량이 전토층에서 15% 이상이므로 아목은 Udands로 분류된다. Ap층과 BA층에서는 Allophane과 Al-유기복합체가 혼재되어 있으나, Bw층에서는 활성 Al이 주로 Allophane의 구성분으로 존재하고 있으며, 전 토층을 통하여 Allophane과 Ferrihydrite 함량이 높다. 습윤시 명도와 채도 값이 Ap, BA 및 Bw층 모두에서 2 이하이고, 유기탄소 함량이 각각 $125,\;115,\;42g\;kg^{-1}$이며, melanic index가 각각 1.53, 1.50, 1.55이다. 0 에서 72 cm 깊이까지 모든 층위에서 melanic 감식표층의 분류조건을 충족시키고 있다. 따라서 대군은 Melanudands로 분류된다. Ap, BA 및 Bw층에서 토양수분장력 1,500 kPa일 때 토양수분함량이 풍건 시료의 경우 각각 28.9, 29.1, 27.6%로 15% 이상이며, 비풍건 시료의 경우 34.2, 55.3, 48.7%로 70% 이하이다. 0~72 cm의 깊이에서 유기탄소 함량이 $60g \;kg^{-1}$ 이상이며, 습윤시 명도와 채도 값이 2 이하이므로 아군은 Pachic Melanudands 로 분류된다. 토양수분 제어부위에서 토양수분장력 1,500 kPa일때 토양수분함량이 풍건 시료의 경우 12% 이상이며, 비풍건 시료의 경우 30~100% 범위 내에 있으므로 대체 토성속은 medial에 속한다. 8 x acid oxalate 침출 Si(%) + 2 x acid oxalate 침출 Fe(%) 값이 광물속 제어부위에서 12.3~19.5로 5 이상이다. 또한 2 x acid oxalate 침출 Fe 값이 8 x acid oxalate 침출 Si(%) 값보다 크므로 광물속은 ferrihydritic에 속한다. 남원통은 thermic 토양온도상을 보유하므로 ashy, thermic family of Typic Melanudands가 아니라 medial, ferrihydritic, thermic family of Pachic Melanudands로 분류되어야 한다.

• 수산해양교육연구
• /
• 제27권6호
• /
• pp.1764-1782
• /
• 2015

The purpose of this study is to investigate the understanding on the acid-base, acid rain and soil acidification of the elementary students. The participants in the current study were 280 6th graders from a elementary school in Gyeongnam Province. A questionnaire consists of four categories: understanding of (a) acid-base basic knowledge, (b) acid rain and (c) soil acidification. (d) In addition, students were asked to comment about the introduction of the acid rain experiment in the science textbook. The results are as follows; First, the results regarding acid-base basic knowledge. They know the classification, characteristics, and properties of acid-based solutions well but they don't know the acid-base neutralization, examples using properties and application in real life. Second, the results regarding acid rain, students know the definition and damage of acid rain but they don't know the causing substances, emission source and way of solution of acid rain for lack of knowledge. Third, the results regarding soil acidification was the well-known part for the students because they had continued learning about the soil from the lesson of acid rain. Also, we looked into the difference in gender and region about the understanding of acid-base, acid rain and soil acidification. According to the gender of the data about the understanding of acid-base, acid rain and soil acidification, the percentage of correct answers of female was higher than male's. Also we expected that urban students were higher than rural students on the understanding of acid-base, acid rain and soil acidification, but the understanding of urban students were similar to rural students. Fourth, we got positive answers and negative answers to the introduction of acid rain experiment. Most of the positive opinion were I want to know a lot acid rain experiment", followed by "It is possible to prevent the risk of the damage and It seems to having fun and new order. Most of the negative opinion were Acid rain experiment may be difficult and complicated followed by Just a theory in the book is enough, Acid rain experiment were boring and not fun, Acid rain experiment is dangerous, There are many to study in this order.

• 한국토양비료학회지
• /
• 제34권1호
• /
• pp.71-75
• /
• 2001

포화침출액의 전기전도도, ECe와 토양과 증류수를 1:5로 하여 측정된 EC1:5간의 직선 관계식의 경사 또는 희석 배수 (DF)에 대해 서로 독립적으로 발표된 연구 결과를 분석한 결과, DF는 CEC와 고도의 유의성을 보이는 부상관 관계에 있었다. 이 관계로부터 한국 대표 토양에 대한표토의 CEC로부터 산출한 DF는 사토에서 12.29, 식토에서 6.44이었다. 이 연구에서 포화수분점에 대한 조사가 이루어지지 않았으나, 측정된 EC1:5로부터 ECe를 추정할 때 토양의 CEC를 고려해야 하며, 제시된 토성에 따른 DF값의 적용이 바람직할 것으로 판단되었다.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제6권4호
• /
• pp.97-112
• /
• 2001

지하수의 보전 보호를 위한 정책 중 가장 중요한 것이 지역적으로 지하수 보전구역을 지정하여 관리하는 것이며, 지하수 보전구역은 지하수법(제12조)에 의하여 지하수 보전지구와 개발제한지구로 분류되어 관리하도록 규정되어 있다. 금번연구에서는 GIS(지리정보시스템)을 이용하여 서울시 지하수 분류도를 먼저 작성한 후 가장 수질이 양호한 1급 및 2급 지하수 대창지역(상류의 지하수 함양지역이나 유일 대수층지역 등)을 지하수 보전지구의 우선 대상지역으로 선정하였으며, 지하수분류는 건설교통부(2000)에서 제시한 지하수의 현재 수질상태, 음용수원으로서의 현재 및 장래 이용성, 기초 수리지질특성, 각종 지하수오염유발행위.시설 소재여부 등에 따라 4등급 분류방법을 기본으로 하였다. 작성된 지하수 분류도에서 1차 선정된 서울시 지하수 보전지구 우선 대상지는 약 57,1$\textrm{km}^2$(서울시 전체면적의 약 9.4%)로 나타났으며, 보전지구의 최종 지정을 위해서는 대상지역에 대한 지하수 정밀조사가 필요하다. 또한 지하수 보전지구의 관리방안도 제주도(2000)와 건설교통부(2000)의 지하수 보전관리계획을 참조하여 서울시에 적합한 안이 마련되었다.