• Journal of the Korean association of regional geographers
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• v.19 no.4
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• pp.737-746
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• 2013

This study was carried out to suggest plan of earth surface erosion by typifying landforms in Gwangeung Forest. Elements of landform were classifyed as hierachical system by scale. Scale for classification set a decision as four categories. We could classify landforms which level zero is 4 levels of elements, level one is 6, level two is twelve, level three is twenty seven. However, micro landforms of valley bottom which is hard to mapping made a categorization as upper valley, middle valley, artificial channel valley. Plan for soil erosion suggested yarding corridor, landform management for surroundings of slope and bridge using rock and gravel, road construction for forest management stable bedrock rather than soil layer, repose angles and piling up rocks for channel walls, and setting up buffer zone when forest thinning be carried out. The result of this research will be expected to provide information for forest management of mountainous areas by landform types.

• Korean Journal of Environment and Ecology
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• v.12 no.2
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• pp.119-130
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• 1998

The purposes of this study were to investigate vegetation structure and to present management plan of mountain type green space in Kangwhado, Inchon. The actual vegetation in survey sites(11,331ha) was divided into 19 community types. It was consisted of secondary forest(92.32%) which was Quercus acutissima, Pinus densiflora-Q. acutissima, and Q. mongolica community so on. Artificial planting forest area, such as Robinia pseudoacacia and Pinus rigida forest and others, was 5.40%(612ha) and it was less than cases in other cities in the Metropolitan area. According to the classification by TWINSPAN, 57 survey plots were divided into seven community types; P rigida(community A), Q. acutissima(community B) P. densiflora-Q. acutissima(community C), Q. acutissima-P. densiflora (community D), P. densiflora-Carpinus laxiflora-Q. serrata-Q. acutissima(community E), Q. serrata-Q. mongolica(community F), and Zelkova serrata-Acer mono(community G). From this result, ecological succession trend of vegetation in this area seems to be change from P. densiflora forest through Q. acutissima forest to Q. mongolica, Q. serrata, and C. laxiflora forest. It was similar to the ordinary successional trend of temperate deciduous forest in middle area, Korea. In addition, this study area was showed acid soil(pH 4.17). Therefore, there is a need for managing the soil environment for effective vegetation management.

• Journal of Korean Society of Forest Science
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• v.39 no.1
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• pp.35-46
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• 1978

The morphological characteristics of vascular bundle sheath occurring on the culm wall were investigated by using many species of Bambusa and Sasa in order to test new classification method for endomorphological charateristics of Bamboos. The results obtained were as follows. 1. As for the thickness of the culm wall in the culm, it was shown that the culm wall of the Bambusa becomes thinner in propertion to its nearness to the upper part of the tree, but no distinctive difference appeared in the Sasa. 2. It was shown that many species of Bambusa has a, b types but the Sasa had a' type and had a, b types. 3. It was shown that many species of Bambusa had e', h, and i types but the Sasa had not them and both of species had not f type. 4. It was shown that many species of Bambusa had c, d, e, and g types, but the Sasa had c, d, and e types and had not g type. 5. In the classification of Bambusa and Sasa, The method of the physiological classification was more effective than test of external observation, and it will encourage further study.

• Journal of Korean Society of Forest Science
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• v.110 no.4
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• pp.516-529
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• 2021

Coniferous forests in the Baekdudaegan protected area are gradually losing their landscape diversity and uniqueness along with their ecological stability due to changes in vegetation composition and structures caused by various disturbance factors, such as climate change, vegetation succession, and human interference. This study provides basic data for establishing a comprehensive conservation plan for coniferous forests in the Baekdudaegan protected area. We classified the vegetation unit types using the Zurich-Montpellier School of Phytosociology and two-way indicator species analysis methods and analyzed the species diversity and structural characteristics based on the vegetation information of 755 stands collected in the natural resources change survey of the Baekdudaegan mountains (2016 to 2020) by the Korea Forest Service. Therefore, the vegetation of the coniferous forests of theBaekdudaegan protected area was classified into 15 types under the vegetation unit hierarchy of two community groups, four communities, seven sub-communities, and 14 variants. Furthermore, we compared the total coverage among vegetation types, importance values, constancy classes, life-forms, and diversity indices. Additionally, the average total coverage and number of species per 100 m² of all coniferous forests were 232% and 21 species, respectively, with the species diversity and dominance indices averaging 1.907 and 0.222, respectively.

• Journal of Korean Society of Forest Science
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• v.94 no.6
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• pp.462-467
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• 2005

This study aims to classify the biotope types and evaluate its functions for acquiring the basic information which can support the landscape ecological management of the urban forest in the case of the three parks in Daegu metropolitan city and then to analyze vegetation landscape patterns. The biotope classification was mostly divided into 5 to 6 biotope type groups in the high units and 15 to 20 biotope types belong to them and then could know that the more big the park size, the more diverse and large the biotope types and its average area. The biotope grade over the three parks was dominating low rank grade (1 to 3 grade) 72.7% that forest organism is inadequate as live, and high grade (7 to 9 grade) did not appear entirely. Most in Biotope function estimation were appeared less than the middle rank grade and biotope area is bigger, those grade rises and temperature could know that is fallen. Vegetation landscape patterns was very simple because only two kinds of Robinia pseudo-acacia and Quercus acutissima is appeared as the dominated landscape elements in all of the three parks. And also because average area of those elements is generally 1ha or so, there was much problems in consecutiveness of functional role as forest ecosystem component. Conclusively, Ecological landscape management need to improve Biotope diversity and functionality, and it secures ecological minimal area and space linkage.

• Industry Promotion Research
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• v.7 no.1
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• pp.1-8
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• 2022

We investigated various types of machine learning methods that can be applied to censored data. Exploratory data analysis reveals the distribution of each feature, relationships among features. Next, classification problem has been set up where the dependent variable is death_event while the rest of the features are independent variables. After applying various machine learning methods to the data, it has been found that just like many other reports from the artificial intelligence arena random forest performs better than logistic regression. But recently well performed artificial neural network and gradient boost do not perform as expected due to the lack of data. Finally Kaplan-Meier and Cox proportional hazard model have been employed to explore the relationship of the dependent variable (t_i, δ_i) with the independent variables. Also random forest which is used in machine learning has been applied to the survival analysis with censored data.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.5
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• pp.103-114
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• 2012

The purpose of this research is classifying stream into different types depending on various factor from the perspective of stream corridor restoration and using it as basic data, which are used to consider efficient management and planning for the healthy stream according to the characteristic by types. In this study, 130 points of location of the Nakdong river basin which consist of various geographic factors have been chosen and hierarchical cluster analysis has been carried out in these points by using biological and physiochemical factors whose health can be considered to be predicted and evaluated. As a result of cluster analysis, there were three divided types. Type A whose biology and water quality are considered the best was the highest in forest area percentage so that it was classified into natural stream. Type B was classified into a rural region stream with a mixture of urban and agricultural region. Type C, with the most damaged water quality and biology health had the most urban region surface area and was named as urban region stream. Moreover, an overall restoration strategy according to characteristic by stream types was set. By the results of correlation analysis on factors, water quality showed a high correlation with biological properties and was affected by surrounding land usage. In evaluation of streams, it proves the need to consider not only other habitat's geographical and biological factors but also the water quality and land usage factors. There needs to be further research on stream ecosystem functionality factors and structural aspects by using a more objective and total evaluation result in selecting additional index and various other specific classification methods by stream types and its restoration strategies.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.106-107
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• 2022

The ship type identification of the surrounding ship is important information for navigators and VTS officers since they can estimate the maneuverability and near-future route of the ships. However, it is more than frequent that the information is not provided due to transmission trouble and seafarers' unfamiliarity with AIS. Thus, this study suggests predicting ship types through the Random Forest classifier after preparing a training and test dataset that contains ship features and types. The AIS data for Ulsan coast in 2018 was used for this study. The method may provide the effect that many navigators and VTS officers discuss and share the experience of predicting ship types.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.4
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• pp.101-111
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• 2008

To provide more natural elements in the harsh urban environment, 'planting trees as urban forests' has been emphasized as having an important role, and trees are expected to be as functional as the trees under more natural conditions in rural areas, and provide people with benefits. To do this, urban forest policies needed a better idea of planting methods and management of trees through the theory of landscape ecology, and also the feedback system according to the evaluation and assessment of urban forests. In this case study, a new principle and assessment indices for the evaluation are applied for the 4 urban forests in two Korean metropolitan cities, Daejeon and Ulsan. The evaluation of Korean urban forest-function as biotope and the assessment for the classification of biotope diversity types are carried out. The AUEM(Adding Up Estimation Matrix) is applied for the analysis of urban forests. Unlikely previous researches on the other Korean metropolitan cities, the size of urban forest has less influence on the vegetation diversity. The most frequent biotope grade is the 3rd grade at Namseon park and Mt. Hamwol, while Mt. Bomun and Mt. Yeompo show the 4th grade. The grades of forest-function as biotope are from 3rd to 5th in which lower than average in forest-function grades. This means that the 4 sites are still not-matured forests and less-functional forests as the urban biotope.

• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.439-442
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• 1999

It is important to analyze the seasonal change profiles of land cover type in large scale for establishing preservation strategy and environmental monitoring. Because the NOAA-AVHRR data sets provide global data with high temporal resolution, it is suitable for the land cover classification of the large area. The objectives of this study were to classify land cover of Korea, to investigate the phenological profiles of land cover. The NOAA-AVHRR data from Jan. 1998 to Dec. 1998 were received by Korea Ocean Research & Development Institute(KORDI) and were used for this study. The NDVI data were produced from this data. And monthly maximum value composite data were made for reducing cloud effect and temporal classification. And the data were classified using the method of supervised classification. To label the land cover classes, they were classified again using generalized vegetation map and Landsat-TM classified image. And the profiles of each class was analyzed according to each month. Results of this study can be summarized as follows. First, it was verified that the use of vegetation map and TM classified map was available to obtain the temporal class labeling with NOAA-AVHRR. Second, phenological characteristics of plant communities of Korea using NOAA-AVHRR was identified. Third, NDVI of North Korea is lower on Summer than that of South Korea. And finally, Forest cover is higher than another cover types. Broadleaf forest is highest on may. Outline of covertype profiles was investigated.